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  30                  <h1>Coding Guidelines</h1>
  31                  <p>Olympus coding guidelines document</p>
  32                  <p style="display: none;"><a href="#start_here">Skip</a></p>
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  44  
  45  <p>These are the phpBB Coding Guidelines for Olympus, all attempts should be made to follow them as closely as possible.</p>
  46  
  47  <h1>Coding Guidelines</h1>
  48  
  49      <div class="paragraph menu">
  50          <div class="inner"><span class="corners-top"><span></span></span>
  51  
  52          <div class="content">
  53  
  54  <ol>
  55      <li><a href="#defaults">Defaults</a>
  56      <ol style="list-style-type: lower-roman;">
  57          <li><a href="#editorsettings">Editor Settings</a></li>
  58          <li><a href="#fileheader">File Header</a></li>
  59          <li><a href="#locations">File Locations</a></li>
  60          <li><a href="#constants">Special Constants</a></li>
  61      </ol>
  62      </li>
  63      <li><a href="#code">Code Layout/Guidelines</a>
  64      <ol style="list-style-type: lower-roman;">
  65          <li><a href="#namingvars">Variable/Function Naming</a></li>
  66          <li><a href="#codelayout">Code Layout</a></li>
  67          <li><a href="#sql">SQL/SQL Layout</a></li>
  68          <li><a href="#optimizing">Optimizations</a></li>
  69          <li><a href="#general">General Guidelines</a></li>
  70      </ol>
  71      </li>
  72      <li><a href="#styling">Styling</a>
  73      <ol style="list-style-type: lower-roman;">
  74          <li><a href="#cfgfiles">Style Config Files</a></li>
  75          <li><a href="#genstyling">General Styling Rules</a></li>
  76      </ol></li>
  77      <li><a href="#templating">Templating</a>
  78      <ol style="list-style-type: lower-roman;">
  79          <li><a href="#templates">General Templating</a></li>
  80          <li><a href="#inheritance">Template Inheritance</a></li>
  81      </ol></li>
  82      <li><a href="#charsets">Character Sets and Encodings</a></li>
  83      <li><a href="#translation">Translation (<abbr title="Internationalisation">i18n</abbr>/<abbr title="Localisation">L10n</abbr>) Guidelines</a>
  84      <ol style="list-style-type: lower-roman;">
  85          <li><a href="#standardisation">Standardisation</a></li>
  86          <li><a href="#otherconsiderations">Other considerations</a></li>
  87          <li><a href="#writingstyle">Writing Style</a></li>
  88      </ol>
  89      </li>
  90      <li><a href="#disclaimer">Copyright and disclaimer</a></li>
  91  </ol>
  92  
  93          </div>
  94  
  95          <span class="corners-bottom"><span></span></span></div>
  96      </div>
  97  
  98      <hr />
  99  
 100  <a name="defaults"></a><h2>1. Defaults</h2>
 101  
 102      <div class="paragraph">
 103          <div class="inner"><span class="corners-top"><span></span></span>
 104  
 105          <div class="content">
 106  
 107  <a name="editorsettings"></a><h3>1.i. Editor Settings</h3>
 108  
 109      <h4>Tabs vs Spaces:</h4>
 110      <p>In order to make this as simple as possible, we will be using tabs, not spaces. We enforce 4 (four) spaces for one tab - therefore you need to set your tab width within your editor to 4 spaces. Make sure that when you <strong>save</strong> the file, it's saving tabs and not spaces. This way, we can each have the code be displayed the way we like it, without breaking the layout of the actual files.</p>
 111      <p>Tabs in front of lines are no problem, but having them within the text can be a problem if you do not set it to the amount of spaces every one of us uses. Here is a short example of how it should look like:</p>
 112  
 113      <div class="codebox"><pre>
 114  {TAB}$mode{TAB}{TAB}= request_var('mode', '');
 115  {TAB}$search_id{TAB}= request_var('search_id', '');
 116      </pre></div>
 117  
 118      <p>If entered with tabs (replace the {TAB}) both equal signs need to be on the same column.</p>
 119  
 120      <h3>Linefeeds:</h3>
 121      <p>Ensure that your editor is saving files in the UNIX (LF) line ending format. This means that lines are terminated with a newline, not with Windows Line endings (CR/LF combo) as they are on Win32 or Classic Mac (CR) Line endings. Any decent editor should be able to do this, but it might not always be the default setting. Know your editor. If you want advice for an editor for your Operating System, just ask one of the developers. Some of them do their editing on Win32.</p>
 122  
 123      <a name="fileheader"></a><h3>1.ii. File Header</h3>
 124  
 125      <h4>Standard header for new files:</h4>
 126      <p>This template of the header must be included at the start of all phpBB files: </p>
 127  
 128      <div class="codebox"><pre>
 129  /**
 130  *
 131  * @package {PACKAGENAME}
 132  * @copyright (c) 2007 phpBB Group
 133  * @license http://opensource.org/licenses/gpl-2.0.php GNU General Public License v2
 134  *
 135  */
 136      </pre></div>
 137  
 138      <p>Please see the <a href="#locations">File Locations section</a> for the correct package name.</p>
 139  
 140      <h4>Files containing inline code:</h4>
 141  
 142      <p>For those files you have to put an empty comment directly after the header to prevent the documentor assigning the header to the first code element found.</p>
 143  
 144      <div class="codebox"><pre>
 145  /**
 146  * {HEADER}
 147  */
 148  
 149  /**
 150  */
 151  {CODE}
 152      </pre></div>
 153  
 154      <h4>Files containing only functions:</h4>
 155  
 156      <p>Do not forget to comment the functions (especially the first function following the header). Each function should have at least a comment of what this function does. For more complex functions it is recommended to document the parameters too.</p>
 157  
 158      <h4>Files containing only classes:</h4>
 159  
 160      <p>Do not forget to comment the class. Classes need a separate @package definition, it is the same as the header package name. Apart from this special case the above statement for files containing only functions needs to be applied to classes and it's methods too.</p>
 161  
 162      <h4>Code following the header but only functions/classes file:</h4>
 163  
 164      <p>If this case is true, the best method to avoid documentation confusions is adding an ignore command, for example:</p>
 165  
 166      <div class="codebox"><pre>
 167  /**
 168  * {HEADER}
 169  */
 170  
 171  /**
 172  * @ignore
 173  */
 174  Small code snipped, mostly one or two defines or an if statement
 175  
 176  /**
 177  * {DOCUMENTATION}
 178  */
 179  class ...
 180      </pre></div>
 181  
 182      <a name="locations"></a><h3>1.iii. File Locations</h3>
 183  
 184      <p>Functions used by more than one page should be placed in functions.php, functions specific to one page should be placed on that page (at the bottom) or within the relevant sections functions file. Some files in <code>/includes</code> are holding functions responsible for special sections, for example uploading files, displaying &quot;things&quot;, user related functions and so forth.</p>
 185  
 186      <p>The following packages are defined, and related new features/functions should be placed within the mentioned files/locations, as well as specifying the correct package name. The package names are bold within this list:</p>
 187  
 188      <ul>
 189          <li><strong>phpBB3</strong><br />Core files and all files not assigned to a separate package</li>
 190          <li><strong>acm</strong><br /><code>/includes/acm</code>, <code>/includes/cache.php</code><br />Cache System</li>
 191          <li><strong>acp</strong><br /><code>/adm</code>, <code>/includes/acp</code>, <code>/includes/functions_admin.php</code><br />Administration Control Panel</li>
 192          <li><strong>dbal</strong><br /><code>/includes/db</code><br />Database Abstraction Layer.<br />Base class is <code>dbal</code>
 193              <ul>
 194                  <li><code>/includes/db/dbal.php</code><br />Base DBAL class, defining the overall framework</li>
 195                  <li><code>/includes/db/firebird.php</code><br />Firebird/Interbase Database Abstraction Layer</li>
 196                  <li><code>/includes/db/msssql.php</code><br />MSSQL Database Abstraction Layer</li>
 197                  <li><code>/includes/db/mssql_odbc.php</code><br />MSSQL ODBC Database Abstraction Layer for MSSQL</li>
 198                  <li><code>/includes/db/mysql.php</code><br />MySQL Database Abstraction Layer for MySQL 3.x/4.0.x/4.1.x/5.x</li>
 199                  <li><code>/includes/db/mysqli.php</code><br />MySQLi Database Abstraction Layer</li>
 200                  <li><code>/includes/db/oracle.php</code><br />Oracle Database Abstraction Layer</li>
 201                  <li><code>/includes/db/postgres.php</code><br />PostgreSQL Database Abstraction Layer</li>
 202                  <li><code>/includes/db/sqlite.php</code><br />Sqlite Database Abstraction Layer</li>
 203              </ul>
 204          </li>
 205          <li><strong>diff</strong><br /><code>/includes/diff</code><br />Diff Engine</li>
 206          <li><strong>docs</strong><br /><code>/docs</code><br />phpBB Documentation</li>
 207          <li><strong>images</strong><br /><code>/images</code><br />All global images not connected to styles</li>
 208          <li><strong>install</strong><br /><code>/install</code><br />Installation System</li>
 209          <li><strong>language</strong><br /><code>/language</code><br />All language files</li>
 210          <li><strong>login</strong><br /><code>/includes/auth</code><br />Login Authentication Plugins</li>
 211          <li><strong>VC</strong><br /><code>/includes/captcha</code><br />CAPTCHA</li>
 212          <li><strong>mcp</strong><br /><code>mcp.php</code>, <code>/includes/mcp</code>, <code>report.php</code><br />Moderator Control Panel</li>
 213          <li><strong>ucp</strong><br /><code>ucp.php</code>, <code>/includes/ucp</code><br />User Control Panel</li>
 214          <li><strong>utf</strong><br /><code>/includes/utf</code><br />UTF8-related functions/classes</li>
 215          <li><strong>search</strong><br /><code>/includes/search</code>, <code>search.php</code><br />Search System</li>
 216          <li><strong>styles</strong><br /><code>/styles</code>, <code>style.php</code><br />phpBB Styles/Templates/Themes/Imagesets</li>
 217      </ul>
 218  
 219      <a name="constants"></a><h3>1.iv. Special Constants</h3>
 220  
 221      <p>There are some special constants application developers are able to utilize to bend some of phpBB's internal functionality to suit their needs.</p>
 222  
 223      <div class="codebox"><pre>
 224  PHPBB_MSG_HANDLER          (overwrite message handler)
 225  PHPBB_DB_NEW_LINK          (overwrite new_link parameter for sql_connect)
 226  PHPBB_ROOT_PATH            (overwrite $phpbb_root_path)
 227  PHPBB_ADMIN_PATH           (overwrite $phpbb_admin_path)
 228  PHPBB_USE_BOARD_URL_PATH   (use generate_board_url() for image paths instead of $phpbb_root_path)
 229  PHPBB_DISABLE_ACP_EDITOR   (disable ACP style editor for templates)
 230  PHPBB_DISABLE_CONFIG_CHECK (disable ACP config.php writeable check)
 231  
 232  PHPBB_ACM_MEMCACHE_PORT     (overwrite memcached port, default is 11211)
 233  PHPBB_ACM_MEMCACHE_COMPRESS (overwrite memcached compress setting, default is disabled)
 234  PHPBB_ACM_MEMCACHE_HOST     (overwrite memcached host name, default is localhost)
 235  
 236  PHPBB_ACM_REDIS_HOST        (overwrite redis host name, default is localhost)
 237  PHPBB_ACM_REDIS_PORT        (overwrite redis port, default is 6379)
 238  PHPBB_ACM_REDIS_PASSWORD    (overwrite redis password, default is empty)
 239  PHPBB_ACM_REDIS_DB          (overwrite redis default database)
 240  
 241  PHPBB_QA                   (Set board to QA-Mode, which means the updater also checks for RC-releases)
 242  </pre></div>
 243  
 244  <h4>PHPBB_USE_BOARD_URL_PATH</h4>
 245  
 246  <p>If the <code>PHPBB_USE_BOARD_URL_PATH</code> constant is set to true, phpBB uses generate_board_url() (this will return the boards url with the script path included) on all instances where web-accessible images are loaded. The exact locations are:</p>
 247  
 248  <ul>
 249      <li>/includes/session.php - user::img()</li>
 250      <li>/includes/functions_content.php - smiley_text()</li>
 251  </ul>
 252  
 253  <p>Path locations for the following template variables are affected by this too:</p>
 254  
 255  <ul>
 256      <li>{T_THEME_PATH} - styles/xxx/theme</li>
 257      <li>{T_TEMPLATE_PATH} - styles/xxx/template</li>
 258      <li>{T_SUPER_TEMPLATE_PATH} - styles/xxx/template</li>
 259      <li>{T_IMAGESET_PATH} - styles/xxx/imageset</li>
 260      <li>{T_IMAGESET_LANG_PATH} - styles/xxx/imageset/yy</li>
 261      <li>{T_IMAGES_PATH} - images/</li>
 262      <li>{T_SMILIES_PATH} - $config['smilies_path']/</li>
 263      <li>{T_AVATAR_PATH} - $config['avatar_path']/</li>
 264      <li>{T_AVATAR_GALLERY_PATH} - $config['avatar_gallery_path']/</li>
 265      <li>{T_ICONS_PATH} - $config['icons_path']/</li>
 266      <li>{T_RANKS_PATH} - $config['ranks_path']/</li>
 267      <li>{T_UPLOAD_PATH} - $config['upload_path']/</li>
 268      <li>{T_STYLESHEET_LINK} - styles/xxx/theme/stylesheet.css (or link to style.php if css is parsed dynamically)</li>
 269      <li>New template variable {BOARD_URL} for the board url + script path.</li>
 270  </ul>
 271  
 272          </div>
 273  
 274          <div class="back2top"><a href="#wrap" class="top">Back to Top</a></div>
 275  
 276          <span class="corners-bottom"><span></span></span></div>
 277      </div>
 278  
 279      <hr />
 280  
 281  <a name="code"></a><h2>2. Code Layout/Guidelines</h2>
 282  
 283      <div class="paragraph">
 284          <div class="inner"><span class="corners-top"><span></span></span>
 285  
 286          <div class="content">
 287  
 288      <p>Please note that these guidelines apply to all php, html, javascript and css files.</p>
 289  
 290      <a name="namingvars"></a><h3>2.i. Variable/Function Naming</h3>
 291  
 292      <p>We will not be using any form of hungarian notation in our naming conventions. Many of us believe that hungarian naming is one of the primary code obfuscation techniques currently in use.</p>
 293  
 294      <h4>Variable Names:</h4>
 295      <p>Variable names should be in all lowercase, with words separated by an underscore, example:</p>
 296  
 297      <div class="indent">
 298          <p><code>$current_user</code> is right, but <code>$currentuser</code> and <code> $currentUser</code> are not.</p>
 299      </div>
 300  
 301      <p>Names should be descriptive, but concise. We don't want huge sentences as our variable names, but typing an extra couple of characters is always better than wondering what exactly a certain variable is for. </p>
 302  
 303      <h4>Loop Indices:</h4>
 304      <p>The <em>only</em> situation where a one-character variable name is allowed is when it's the index for some looping construct. In this case, the index of the outer loop should always be $i. If there's a loop inside that loop, its index should be $j, followed by $k, and so on. If the loop is being indexed by some already-existing variable with a meaningful name, this guideline does not apply, example:</p>
 305  
 306      <div class="codebox"><pre>
 307  for ($i = 0; $i &lt; $outer_size; $i++)
 308  {
 309     for ($j = 0; $j &lt; $inner_size; $j++)
 310     {
 311        foo($i, $j);
 312     }
 313  }
 314      </pre></div>
 315  
 316      <h4>Function Names:</h4>
 317      <p>Functions should also be named descriptively. We're not programming in C here, we don't want to write functions called things like "stristr()". Again, all lower-case names with words separated by a single underscore character. Function names should preferably have a verb in them somewhere. Good function names are <code>print_login_status()</code>, <code>get_user_data()</code>, etc. </p>
 318  
 319      <h4>Function Arguments:</h4>
 320      <p>Arguments are subject to the same guidelines as variable names. We don't want a bunch of functions like: <code>do_stuff($a, $b, $c)</code>. In most cases, we'd like to be able to tell how to use a function by just looking at its declaration. </p>
 321  
 322      <h4>Summary:</h4>
 323      <p>The basic philosophy here is to not hurt code clarity for the sake of laziness. This has to be balanced by a little bit of common sense, though; <code>print_login_status_for_a_given_user()</code> goes too far, for example -- that function would be better named <code>print_user_login_status()</code>, or just <code>print_login_status()</code>.</p>
 324  
 325      <h4>Special Namings: </h4>
 326      <p>For all emoticons use the term <code>smiley</code> in singular and <code>smilies</code> in plural.</p>
 327  
 328      <a name="codelayout"></a><h3>2.ii. Code Layout</h3>
 329  
 330      <h4>Always include the braces:</h4>
 331      <p>This is another case of being too lazy to type 2 extra characters causing problems with code clarity. Even if the body of some construct is only one line long, do <em>not</em> drop the braces. Just don't, examples:</p>
 332  
 333      <p class="bad">// These are all wrong. </p>
 334  
 335      <div class="codebox"><pre>
 336  if (condition) do_stuff();
 337  
 338  if (condition)
 339      do_stuff();
 340  
 341  while (condition)
 342      do_stuff();
 343  
 344  for ($i = 0; $i &lt; size; $i++)
 345      do_stuff($i);
 346      </pre></div>
 347  
 348      <p class="good">// These are all right. </p>
 349      <div class="codebox"><pre>
 350  if (condition)
 351  {
 352      do_stuff();
 353  }
 354  
 355  while (condition)
 356  {
 357      do_stuff();
 358  }
 359  
 360  for ($i = 0; $i &lt; size; $i++)
 361  {
 362      do_stuff();
 363  }
 364      </pre></div>
 365  
 366      <h4>Where to put the braces:</h4>
 367      <p>This one is a bit of a holy war, but we're going to use a style that can be summed up in one sentence: Braces always go on their own line. The closing brace should also always be at the same column as the corresponding opening brace, examples:</p>
 368  
 369      <div class="codebox"><pre>
 370  if (condition)
 371  {
 372      while (condition2)
 373      {
 374          ...
 375      }
 376  }
 377  else
 378  {
 379      ...
 380  }
 381  
 382  for ($i = 0; $i &lt; $size; $i++)
 383  {
 384      ...
 385  }
 386  
 387  while (condition)
 388  {
 389      ...
 390  }
 391  
 392  function do_stuff()
 393  {
 394      ...
 395  }
 396      </pre></div>
 397  
 398      <h4>Use spaces between tokens:</h4>
 399      <p>This is another simple, easy step that helps keep code readable without much effort. Whenever you write an assignment, expression, etc.. Always leave <em>one</em> space between the tokens. Basically, write code as if it was English. Put spaces between variable names and operators. Don't put spaces just after an opening bracket or before a closing bracket. Don't put spaces just before a comma or a semicolon. This is best shown with a few examples, examples:</p>
 400  
 401      <p>// Each pair shows the wrong way followed by the right way. </p>
 402  
 403      <div class="codebox"><pre>
 404  $i=0;
 405  $i = 0;
 406  
 407  if($i&lt;7) ...
 408  if ($i &lt; 7) ...
 409  
 410  if ( ($i &lt; 7)&amp;&amp;($j &gt; 8) ) ...
 411  if ($i &lt; 7 &amp;&amp; $j &gt; 8) ...
 412  
 413  do_stuff( $i, 'foo', $b );
 414  do_stuff($i, 'foo', $b);
 415  
 416  for($i=0; $i&lt;$size; $i++) ...
 417  for ($i = 0; $i &lt; $size; $i++) ...
 418  
 419  $i=($j &lt; $size)?0:1;
 420  $i = ($j &lt; $size) ? 0 : 1;
 421      </pre></div>
 422  
 423      <h4>Operator precedence:</h4>
 424      <p>Do you know the exact precedence of all the operators in PHP? Neither do I. Don't guess. Always make it obvious by using brackets to force the precedence of an equation so you know what it does. Remember to not over-use this, as it may harden the readability. Basically, do not enclose single expressions. Examples:</p>
 425  
 426      <p class="bad">// what's the result? who knows. </p>
 427      <div class="codebox"><pre>
 428  $bool = ($i &lt; 7 &amp;&amp; $j &gt; 8 || $k == 4);
 429      </pre></div>
 430  
 431      <p class="bad">// now you can be certain what I'm doing here.</p>
 432      <div class="codebox"><pre>
 433  $bool = (($i &lt; 7) &amp;&amp; (($j &lt; 8) || ($k == 4)));
 434      </pre></div>
 435  
 436      <p class="good">// But this one is even better, because it is easier on the eye but the intention is preserved</p>
 437      <div class="codebox"><pre>
 438  $bool = ($i &lt; 7 &amp;&amp; ($j &lt; 8 || $k == 4));
 439      </pre></div>
 440  
 441      <h4>Quoting strings:</h4>
 442      <p>There are two different ways to quote strings in PHP - either with single quotes or with double quotes. The main difference is that the parser does variable interpolation in double-quoted strings, but not in single quoted strings. Because of this, you should <em>always</em> use single quotes <em>unless</em> you specifically need variable interpolation to be done on that string. This way, we can save the parser the trouble of parsing a bunch of strings where no interpolation needs to be done.</p>
 443      <p>Also, if you are using a string variable as part of a function call, you do not need to enclose that variable in quotes. Again, this will just make unnecessary work for the parser. Note, however, that nearly all of the escape sequences that exist for double-quoted strings will not work with single-quoted strings. Be careful, and feel free to break this guideline if it's making your code easier to read, examples:</p>
 444  
 445      <p class="bad">// wrong </p>
 446      <div class="codebox"><pre>
 447  $str = "This is a really long string with no variables for the parser to find.";
 448  
 449  do_stuff("$str");
 450      </pre></div>
 451  
 452      <p class="good">// right</p>
 453      <div class="codebox"><pre>
 454  $str = 'This is a really long string with no variables for the parser to find.';
 455  
 456  do_stuff($str);
 457      </pre></div>
 458  
 459      <p class="bad">// Sometimes single quotes are just not right</p>
 460      <div class="codebox"><pre>
 461  $post_url = $phpbb_root_path . 'posting.' . $phpEx . '?mode=' . $mode . '&amp;amp;start=' . $start;
 462      </pre></div>
 463  
 464      <p class="good">// Double quotes are sometimes needed to not overcrowd the line with concatenations.</p>
 465      <div class="codebox"><pre>
 466  $post_url = "{$phpbb_root_path}posting.$phpEx?mode=$mode&amp;amp;start=$start";
 467      </pre></div>
 468  
 469      <p>In SQL statements mixing single and double quotes is partly allowed (following the guidelines listed here about SQL formatting), else one should try to only use one method - mostly single quotes.</p>
 470  
 471      <h4>Associative array keys:</h4>
 472      <p>In PHP, it's legal to use a literal string as a key to an associative array without quoting that string. We don't want to do this -- the string should always be quoted to avoid confusion. Note that this is only when we're using a literal, not when we're using a variable, examples:</p>
 473  
 474      <p class="bad">// wrong</p>
 475      <div class="codebox"><pre>
 476  $foo = $assoc_array[blah];
 477      </pre></div>
 478  
 479      <p class="good">// right </p>
 480      <div class="codebox"><pre>
 481  $foo = $assoc_array['blah'];
 482      </pre></div>
 483  
 484      <p class="bad">// wrong</p>
 485      <div class="codebox"><pre>
 486  $foo = $assoc_array["$var"];
 487      </pre></div>
 488  
 489      <p class="good">// right </p>
 490      <div class="codebox"><pre>
 491  $foo = $assoc_array[$var];
 492      </pre></div>
 493  
 494      <h4>Comments:</h4>
 495      <p>Each complex function should be preceded by a comment that tells a programmer everything they need to know to use that function. The meaning of every parameter, the expected input, and the output are required as a minimal comment. The function's behaviour in error conditions (and what those error conditions are) should also be present - but mostly included within the comment about the output.<br /><br />Especially important to document are any assumptions the code makes, or preconditions for its proper operation. Any one of the developers should be able to look at any part of the application and figure out what's going on in a reasonable amount of time.<br /><br />Avoid using <code>/* */</code> comment blocks for one-line comments, <code>//</code> should be used for one/two-liners.</p>
 496  
 497      <h4>Magic numbers:</h4>
 498      <p>Don't use them. Use named constants for any literal value other than obvious special cases. Basically, it's ok to check if an array has 0 elements by using the literal 0. It's not ok to assign some special meaning to a number and then use it everywhere as a literal. This hurts readability AND maintainability. The constants <code>true</code> and <code>false</code> should be used in place of the literals 1 and 0 -- even though they have the same values (but not type!), it's more obvious what the actual logic is when you use the named constants. Typecast variables where it is needed, do not rely on the correct variable type (PHP is currently very loose on typecasting which can lead to security problems if a developer does not keep a very close eye on it).</p>
 499  
 500      <h4>Shortcut operators:</h4>
 501      <p>The only shortcut operators that cause readability problems are the shortcut increment <code>$i++</code> and decrement <code>$j--</code> operators. These operators should not be used as part of an expression. They can, however, be used on their own line. Using them in expressions is just not worth the headaches when debugging, examples:</p>
 502  
 503      <p class="bad">// wrong </p>
 504      <div class="codebox"><pre>
 505  $array[++$i] = $j;
 506  $array[$i++] = $k;
 507      </pre></div>
 508  
 509      <p class="good">// right </p>
 510      <div class="codebox"><pre>
 511  $i++;
 512  $array[$i] = $j;
 513  
 514  $array[$i] = $k;
 515  $i++;
 516      </pre></div>
 517  
 518      <h4>Inline conditionals:</h4>
 519      <p>Inline conditionals should only be used to do very simple things. Preferably, they will only be used to do assignments, and not for function calls or anything complex at all. They can be harmful to readability if used incorrectly, so don't fall in love with saving typing by using them, examples:</p>
 520  
 521      <p class="bad">// Bad place to use them</p>
 522      <div class="codebox"><pre>
 523  ($i &lt; $size &amp;&amp; $j &gt; $size) ? do_stuff($foo) : do_stuff($bar);
 524      </pre></div>
 525  
 526      <p class="good">// OK place to use them </p>
 527      <div class="codebox"><pre>
 528  $min = ($i &lt; $j) ? $i : $j;
 529      </pre></div>
 530  
 531      <h4>Don't use uninitialized variables.</h4>
 532      <p>For phpBB3, we intend to use a higher level of run-time error reporting. This will mean that the use of an uninitialized variable will be reported as a warning. These warnings can be avoided by using the built-in isset() function to check whether a variable has been set - but preferably the variable is always existing. For checking if an array has a key set this can come in handy though, examples:</p>
 533  
 534      <p class="bad">// Wrong </p>
 535      <div class="codebox"><pre>
 536  if ($forum) ...
 537      </pre></div>
 538  
 539      <p class="good">// Right </p>
 540      <div class="codebox"><pre>
 541  if (isset($forum)) ...
 542      </pre></div>
 543  
 544      <p class="good">// Also possible</p>
 545      <div class="codebox"><pre>
 546  if (isset($forum) &amp;&amp; $forum == 5)
 547      </pre></div>
 548  
 549      <p>The <code>empty()</code> function is useful if you want to check if a variable is not set or being empty (an empty string, 0 as an integer or string, NULL, false, an empty array or a variable declared, but without a value in a class). Therefore empty should be used in favor of <code>isset($array) &amp;&amp; sizeof($array) &gt; 0</code> - this can be written in a shorter way as <code>!empty($array)</code>.</p>
 550  
 551      <h4>Switch statements:</h4>
 552      <p>Switch/case code blocks can get a bit long sometimes. To have some level of notice and being in-line with the opening/closing brace requirement (where they are on the same line for better readability), this also applies to switch/case code blocks and the breaks. An example:</p>
 553  
 554      <p class="bad">// Wrong </p>
 555      <div class="codebox"><pre>
 556  switch ($mode)
 557  {
 558      case 'mode1':
 559          // I am doing something here
 560          break;
 561      case 'mode2':
 562          // I am doing something completely different here
 563          break;
 564  }
 565      </pre></div>
 566  
 567      <p class="good">// Good </p>
 568      <div class="codebox"><pre>
 569  switch ($mode)
 570  {
 571      case 'mode1':
 572          // I am doing something here
 573      break;
 574  
 575      case 'mode2':
 576          // I am doing something completely different here
 577      break;
 578  
 579      default:
 580          // Always assume that a case was not caught
 581      break;
 582  }
 583      </pre></div>
 584  
 585      <p class="good">// Also good, if you have more code between the case and the break </p>
 586      <div class="codebox"><pre>
 587  switch ($mode)
 588  {
 589      case 'mode1':
 590  
 591          // I am doing something here
 592  
 593      break;
 594  
 595      case 'mode2':
 596  
 597          // I am doing something completely different here
 598  
 599      break;
 600  
 601      default:
 602  
 603          // Always assume that a case was not caught
 604  
 605      break;
 606  }
 607      </pre></div>
 608  
 609      <p>Even if the break for the default case is not needed, it is sometimes better to include it just for readability and completeness.</p>
 610  
 611      <p>If no break is intended, please add a comment instead. An example:</p>
 612  
 613      <p class="good">// Example with no break </p>
 614      <div class="codebox"><pre>
 615  switch ($mode)
 616  {
 617      case 'mode1':
 618  
 619          // I am doing something here
 620  
 621      // no break here
 622  
 623      case 'mode2':
 624  
 625          // I am doing something completely different here
 626  
 627      break;
 628  
 629      default:
 630  
 631          // Always assume that a case was not caught
 632  
 633      break;
 634  }
 635      </pre></div>
 636  
 637      <a name="sql"></a><h3>2.iii. SQL/SQL Layout</h3>
 638  
 639      <h4>Common SQL Guidelines: </h4>
 640      <p>All SQL should be cross-DB compatible, if DB specific SQL is used alternatives must be provided which work on all supported DB's (MySQL3/4/5, MSSQL (7.0 and 2000), PostgreSQL (7.0+), Firebird, SQLite, Oracle8, ODBC (generalised if possible)).</p>
 641      <p>All SQL commands should utilise the DataBase Abstraction Layer (DBAL)</p>
 642  
 643      <h4>SQL code layout:</h4>
 644      <p>SQL Statements are often unreadable without some formatting, since they tend to be big at times. Though the formatting of sql statements adds a lot to the readability of code. SQL statements should be formatted in the following way, basically writing keywords: </p>
 645  
 646      <div class="codebox"><pre>
 647  $sql = 'SELECT *
 648  &lt;-one tab-&gt;FROM ' . SOME_TABLE . '
 649  &lt;-one tab-&gt;WHERE a = 1
 650  &lt;-two tabs-&gt;AND (b = 2
 651  &lt;-three tabs-&gt;OR b = 3)
 652  &lt;-one tab-&gt;ORDER BY b';
 653      </pre></div>
 654  
 655      <p>Here the example with the tabs applied:</p>
 656  
 657      <div class="codebox"><pre>
 658  $sql = 'SELECT *
 659      FROM ' . SOME_TABLE . '
 660      WHERE a = 1
 661          AND (b = 2
 662              OR b = 3)
 663      ORDER BY b';
 664      </pre></div>
 665  
 666      <h4>SQL Quotes: </h4>
 667      <p>Use double quotes where applicable. (The variables in these examples are typecasted to integers beforehand.) Examples: </p>
 668  
 669      <p class="bad">// These are wrong.</p>
 670      <div class="codebox"><pre>
 671  "UPDATE " . SOME_TABLE . " SET something = something_else WHERE a = $b";
 672  
 673  'UPDATE ' . SOME_TABLE . ' SET something = ' . $user_id . ' WHERE a = ' . $something;
 674      </pre></div>
 675  
 676      <p class="good">// These are right. </p>
 677  
 678      <div class="codebox"><pre>
 679  'UPDATE ' . SOME_TABLE . " SET something = something_else WHERE a = $b";
 680  
 681  'UPDATE ' . SOME_TABLE . " SET something = $user_id WHERE a = $something";
 682      </pre></div>
 683  
 684      <p>In other words use single quotes where no variable substitution is required or where the variable involved shouldn't appear within double quotes. Otherwise use double quotes.</p>
 685  
 686      <h4>Avoid DB specific SQL: </h4>
 687      <p>The &quot;not equals operator&quot;, as defined by the SQL:2003 standard, is &quot;&lt;&gt;&quot;</p>
 688  
 689      <p class="bad">// This is wrong.</p>
 690      <div class="codebox"><pre>
 691  $sql = 'SELECT *
 692      FROM ' . SOME_TABLE . '
 693      WHERE a != 2';
 694      </pre></div>
 695  
 696      <p class="good">// This is right. </p>
 697      <div class="codebox"><pre>
 698  $sql = 'SELECT *
 699      FROM ' . SOME_TABLE . '
 700      WHERE a &lt;&gt; 2';
 701      </pre></div>
 702  
 703      <h4>Common DBAL methods: </h4>
 704  
 705      <h4>sql_escape():</h4>
 706  
 707      <p>Always use <code>$db-&gt;sql_escape()</code> if you need to check for a string within an SQL statement (even if you are sure the variable cannot contain single quotes - never trust your input), for example:</p>
 708  
 709      <div class="codebox"><pre>
 710  $sql = 'SELECT *
 711      FROM ' . SOME_TABLE . "
 712      WHERE username = '" . $db-&gt;sql_escape($username) . "'";
 713      </pre></div>
 714  
 715      <h4>sql_query_limit():</h4>
 716  
 717      <p>We do not add limit statements to the sql query, but instead use <code>$db-&gt;sql_query_limit()</code>. You basically pass the query, the total number of lines to retrieve and the offset.</p>
 718  
 719      <p><strong>Note: </strong> Since Oracle handles limits differently and because of how we implemented this handling you need to take special care if you use <code>sql_query_limit</code> with an sql query retrieving data from more than one table.</p>
 720  
 721      <p>Make sure when using something like "SELECT x.*, y.jars" that there is not a column named jars in x; make sure that there is no overlap between an implicit column and the explicit columns.</p>
 722  
 723      <h4>sql_build_array():</h4>
 724  
 725      <p>If you need to UPDATE or INSERT data, make use of the <code>$db-&gt;sql_build_array()</code> function. This function already escapes strings and checks other types, so there is no need to do this here. The data to be inserted should go into an array - <code>$sql_ary</code> - or directly within the statement if one or two variables needs to be inserted/updated. An example of an insert statement would be:</p>
 726  
 727      <div class="codebox"><pre>
 728  $sql_ary = array(
 729      'somedata'        =&gt; $my_string,
 730      'otherdata'        =&gt; $an_int,
 731      'moredata'        =&gt; $another_int
 732  );
 733  
 734  $db-&gt;sql_query('INSERT INTO ' . SOME_TABLE . ' ' . $db-&gt;sql_build_array('INSERT', $sql_ary));
 735      </pre></div>
 736  
 737      <p>To complete the example, this is how an update statement would look like:</p>
 738  
 739      <div class="codebox"><pre>
 740  $sql_ary = array(
 741      'somedata'        =&gt; $my_string,
 742      'otherdata'        =&gt; $an_int,
 743      'moredata'        =&gt; $another_int
 744  );
 745  
 746  $sql = 'UPDATE ' . SOME_TABLE . '
 747      SET ' . $db-&gt;sql_build_array('UPDATE', $sql_ary) . '
 748      WHERE user_id = ' . (int) $user_id;
 749  $db-&gt;sql_query($sql);
 750      </pre></div>
 751  
 752      <p>The <code>$db-&gt;sql_build_array()</code> function supports the following modes: <code>INSERT</code> (example above), <code>INSERT_SELECT</code> (building query for <code>INSERT INTO table (...) SELECT value, column ...</code> statements), <code>UPDATE</code> (example above) and <code>SELECT</code> (for building WHERE statement [AND logic]).</p>
 753  
 754      <h4>sql_multi_insert():</h4>
 755  
 756      <p>If you want to insert multiple statements at once, please use the separate <code>sql_multi_insert()</code> method. An example:</p>
 757  
 758      <div class="codebox"><pre>
 759  $sql_ary = array();
 760  
 761  $sql_ary[] = array(
 762      'somedata'        =&gt; $my_string_1,
 763      'otherdata'        =&gt; $an_int_1,
 764      'moredata'        =&gt; $another_int_1,
 765  );
 766  
 767  $sql_ary[] = array(
 768      'somedata'        =&gt; $my_string_2,
 769      'otherdata'        =&gt; $an_int_2,
 770      'moredata'        =&gt; $another_int_2,
 771  );
 772  
 773  $db->sql_multi_insert(SOME_TABLE, $sql_ary);
 774      </pre></div>
 775  
 776      <h4>sql_in_set():</h4>
 777  
 778      <p>The <code>$db-&gt;sql_in_set()</code> function should be used for building <code>IN ()</code> and <code>NOT IN ()</code> constructs. Since (specifically) MySQL tend to be faster if for one value to be compared the <code>=</code> and <code>&lt;&gt;</code> operator is used, we let the DBAL decide what to do. A typical example of doing a positive match against a number of values would be:</p>
 779  
 780      <div class="codebox"><pre>
 781  $sql = 'SELECT *
 782      FROM ' . FORUMS_TABLE . '
 783      WHERE ' . $db-&gt;sql_in_set('forum_id', $forum_ids);
 784  $db-&gt;sql_query($sql);
 785      </pre></div>
 786  
 787      <p>Based on the number of values in $forum_ids, the query can look differently.</p>
 788  
 789      <p class="good">// SQL Statement if $forum_ids = array(1, 2, 3);</p>
 790  
 791      <div class="codebox"><pre>
 792  SELECT FROM phpbb_forums WHERE forum_id IN (1, 2, 3)
 793      </pre></div>
 794  
 795      <p class="good">// SQL Statement if $forum_ids = array(1) or $forum_ids = 1</p>
 796  
 797      <div class="codebox"><pre>
 798  SELECT FROM phpbb_forums WHERE forum_id = 1
 799      </pre></div>
 800  
 801      <p>Of course the same is possible for doing a negative match against a number of values:</p>
 802  
 803      <div class="codebox"><pre>
 804  $sql = 'SELECT *
 805      FROM ' . FORUMS_TABLE . '
 806      WHERE ' . $db-&gt;sql_in_set('forum_id', $forum_ids, <strong>true</strong>);
 807  $db-&gt;sql_query($sql);
 808      </pre></div>
 809  
 810      <p>Based on the number of values in $forum_ids, the query can look differently here too.</p>
 811  
 812      <p class="good">// SQL Statement if $forum_ids = array(1, 2, 3);</p>
 813  
 814      <div class="codebox"><pre>
 815  SELECT FROM phpbb_forums WHERE forum_id <strong>NOT</strong> IN (1, 2, 3)
 816      </pre></div>
 817  
 818      <p class="good">// SQL Statement if $forum_ids = array(1) or $forum_ids = 1</p>
 819  
 820      <div class="codebox"><pre>
 821  SELECT FROM phpbb_forums WHERE forum_id <strong>&lt;&gt;</strong> 1
 822      </pre></div>
 823  
 824      <p>If the given array is empty, an error will be produced.</p>
 825  
 826      <h4>sql_build_query():</h4>
 827  
 828      <p>The <code>$db-&gt;sql_build_query()</code> function is responsible for building sql statements for SELECT and SELECT DISTINCT queries if you need to JOIN on more than one table or retrieve data from more than one table while doing a JOIN. This needs to be used to make sure the resulting statement is working on all supported db's. Instead of explaining every possible combination, I will give a short example:</p>
 829  
 830      <div class="codebox"><pre>
 831  $sql_array = array(
 832      'SELECT'    =&gt; 'f.*, ft.mark_time',
 833  
 834      'FROM'        =&gt; array(
 835          FORUMS_WATCH_TABLE    =&gt; 'fw',
 836          FORUMS_TABLE        =&gt; 'f'
 837      ),
 838  
 839      'LEFT_JOIN'    =&gt; array(
 840          array(
 841              'FROM'    =&gt; array(FORUMS_TRACK_TABLE =&gt; 'ft'),
 842              'ON'    =&gt; 'ft.user_id = ' . $user-&gt;data['user_id'] . ' AND ft.forum_id = f.forum_id'
 843          )
 844      ),
 845  
 846      'WHERE'        =&gt; 'fw.user_id = ' . $user-&gt;data['user_id'] . '
 847          AND f.forum_id = fw.forum_id',
 848  
 849      'ORDER_BY'    =&gt; 'left_id'
 850  );
 851  
 852  $sql = $db-&gt;sql_build_query('SELECT', $sql_array);
 853      </pre></div>
 854  
 855      <p>The possible first parameter for sql_build_query() is SELECT or SELECT_DISTINCT. As you can see, the logic is pretty self-explaining. For the LEFT_JOIN key, just add another array if you want to join on to tables for example. The added benefit of using this construct is that you are able to easily build the query statement based on conditions - for example the above LEFT_JOIN is only necessary if server side topic tracking is enabled; a slight adjustement would be:</p>
 856  
 857      <div class="codebox"><pre>
 858  $sql_array = array(
 859      'SELECT'    =&gt; 'f.*',
 860  
 861      'FROM'        =&gt; array(
 862          FORUMS_WATCH_TABLE    =&gt; 'fw',
 863          FORUMS_TABLE        =&gt; 'f'
 864      ),
 865  
 866      'WHERE'        =&gt; 'fw.user_id = ' . $user-&gt;data['user_id'] . '
 867          AND f.forum_id = fw.forum_id',
 868  
 869      'ORDER_BY'    =&gt; 'left_id'
 870  );
 871  
 872  if ($config['load_db_lastread'])
 873  {
 874      $sql_array['LEFT_JOIN'] = array(
 875          array(
 876              'FROM'    =&gt; array(FORUMS_TRACK_TABLE =&gt; 'ft'),
 877              'ON'    =&gt; 'ft.user_id = ' . $user-&gt;data['user_id'] . ' AND ft.forum_id = f.forum_id'
 878          )
 879      );
 880  
 881      $sql_array['SELECT'] .= ', ft.mark_time ';
 882  }
 883  else
 884  {
 885      // Here we read the cookie data
 886  }
 887  
 888  $sql = $db-&gt;sql_build_query('SELECT', $sql_array);
 889      </pre></div>
 890  
 891      <a name="optimizing"></a><h3>2.iv. Optimizations</h3>
 892  
 893      <h4>Operations in loop definition: </h4>
 894      <p>Always try to optimize your loops if operations are going on at the comparing part, since this part is executed every time the loop is parsed through. For assignments a descriptive name should be chosen. Example:</p>
 895  
 896      <p class="bad">// On every iteration the sizeof function is called</p>
 897      <div class="codebox"><pre>
 898  for ($i = 0; $i &lt; sizeof($post_data); $i++)
 899  {
 900      do_something();
 901  }
 902      </pre></div>
 903  
 904      <p class="good">// You are able to assign the (not changing) result within the loop itself</p>
 905      <div class="codebox"><pre>
 906  for ($i = 0, $size = sizeof($post_data); $i &lt; $size; $i++)
 907  {
 908      do_something();
 909  }
 910      </pre></div>
 911  
 912      <h4>Use of in_array(): </h4>
 913      <p>Try to avoid using in_array() on huge arrays, and try to not place them into loops if the array to check consist of more than 20 entries. in_array() can be very time consuming and uses a lot of cpu processing time. For little checks it is not noticeable, but if checked against a huge array within a loop those checks alone can take several seconds. If you need this functionality, try using isset() on the arrays keys instead, actually shifting the values into keys and vice versa. A call to <code>isset($array[$var])</code> is a lot faster than <code>in_array($var, array_keys($array))</code> for example.</p>
 914  
 915  
 916      <a name="general"></a><h3>2.v. General Guidelines</h3>
 917  
 918      <h4>General things:</h4>
 919      <p>Never trust user input (this also applies to server variables as well as cookies).</p>
 920      <p>Try to sanitize values returned from a function.</p>
 921      <p>Try to sanitize given function variables within your function.</p>
 922      <p>The auth class should be used for all authorisation checking.</p>
 923      <p>No attempt should be made to remove any copyright information (either contained within the source or displayed interactively when the source is run/compiled), neither should the copyright information be altered in any way (it may be added to).</p>
 924  
 925      <h4>Variables: </h4>
 926      <p>Make use of the <code>request_var()</code> function for anything except for submit or single checking params.</p>
 927      <p>The request_var function determines the type to set from the second parameter (which determines the default value too). If you need to get a scalar variable type, you need to tell this the request_var function explicitly. Examples:</p>
 928  
 929      <p class="bad">// Old method, do not use it</p>
 930      <div class="codebox"><pre>
 931  $start = (isset($HTTP_GET_VARS['start'])) ? intval($HTTP_GET_VARS['start']) : intval($HTTP_POST_VARS['start']);
 932  $submit = (isset($HTTP_POST_VARS['submit'])) ? true : false;
 933      </pre></div>
 934  
 935      <p class="good">// Use request var and define a default variable (use the correct type)</p>
 936      <div class="codebox"><pre>
 937  $start = request_var('start', 0);
 938  $submit = (isset($_POST['submit'])) ? true : false;
 939      </pre></div>
 940  
 941      <p class="bad">// $start is an int, the following use of request_var therefore is not allowed</p>
 942      <div class="codebox"><pre>
 943  $start = request_var('start', '0');
 944      </pre></div>
 945  
 946      <p class="good">// Getting an array, keys are integers, value defaults to 0</p>
 947      <div class="codebox"><pre>
 948  $mark_array = request_var('mark', array(0));
 949      </pre></div>
 950  
 951      <p class="good">// Getting an array, keys are strings, value defaults to 0</p>
 952      <div class="codebox"><pre>
 953  $action_ary = request_var('action', array('' =&gt; 0));
 954      </pre></div>
 955  
 956      <h4>Login checks/redirection: </h4>
 957      <p>To show a forum login box use <code>login_forum_box($forum_data)</code>, else use the <code>login_box()</code> function.</p>
 958  
 959      <p><code>$forum_data</code> should contain at least the <code>forum_id</code> and <code>forum_password</code> fields. If the field <code>forum_name</code> is available, then it is displayed on the forum login page.</p>
 960  
 961      <p>The <code>login_box()</code> function can have a redirect as the first parameter. As a thumb of rule, specify an empty string if you want to redirect to the users current location, else do not add the <code>$SID</code> to the redirect string (for example within the ucp/login we redirect to the board index because else the user would be redirected to the login screen).</p>
 962  
 963      <h4>Sensitive Operations: </h4>
 964      <p>For sensitive operations always let the user confirm the action. For the confirmation screens, make use of the <code>confirm_box()</code> function.</p>
 965  
 966      <h4>Altering Operations: </h4>
 967      <p>For operations altering the state of the database, for instance posting, always verify the form token, unless you are already using <code>confirm_box()</code>. To do so, make use of the <code>add_form_key()</code> and <code>check_form_key()</code> functions. </p>
 968      <div class="codebox"><pre>
 969      add_form_key('my_form');
 970  
 971      if ($submit)
 972      {
 973          if (!check_form_key('my_form'))
 974          {
 975              trigger_error('FORM_INVALID');
 976          }
 977      }
 978      </pre></div>
 979  
 980      <p>The string passed to <code>add_form_key()</code> needs to match the string passed to <code>check_form_key()</code>. Another requirement for this to work correctly is that all forms include the <code>{S_FORM_TOKEN}</code> template variable.</p>
 981  
 982  
 983      <h4>Sessions: </h4>
 984      <p>Sessions should be initiated on each page, as near the top as possible using the following code:</p>
 985  
 986      <div class="codebox"><pre>
 987  $user-&gt;session_begin();
 988  $auth-&gt;acl($user-&gt;data);
 989  $user-&gt;setup();
 990      </pre></div>
 991  
 992      <p>The <code>$user-&gt;setup()</code> call can be used to pass on additional language definition and a custom style (used in viewforum).</p>
 993  
 994      <h4>Errors and messages: </h4>
 995      <p>All messages/errors should be outputted by calling <code>trigger_error()</code> using the appropriate message type and language string. Example:</p>
 996  
 997      <div class="codebox"><pre>
 998  trigger_error('NO_FORUM');
 999      </pre></div>
1000  
1001      <div class="codebox"><pre>
1002  trigger_error($user-&gt;lang['NO_FORUM']);
1003      </pre></div>
1004  
1005      <div class="codebox"><pre>
1006  trigger_error('NO_MODE', E_USER_ERROR);
1007      </pre></div>
1008  
1009      <h4>Url formatting</h4>
1010  
1011      <p>All urls pointing to internal files need to be prepended by the <code>$phpbb_root_path</code> variable. Within the administration control panel all urls pointing to internal files need to be prepended by the <code>$phpbb_admin_path</code> variable. This makes sure the path is always correct and users being able to just rename the admin folder and the acp still working as intended (though some links will fail and the code need to be slightly adjusted).</p>
1012  
1013      <p>The <code>append_sid()</code> function from 2.0.x is available too, though it does not handle url alterations automatically. Please have a look at the code documentation if you want to get more details on how to use append_sid(). A sample call to append_sid() can look like this:</p>
1014  
1015      <div class="codebox"><pre>
1016  append_sid(&quot;{$phpbb_root_path}memberlist.$phpEx&quot;, 'mode=group&amp;amp;g=' . $row['group_id'])
1017      </pre></div>
1018  
1019      <h4>General function usage: </h4>
1020  
1021      <p>Some of these functions are only chosen over others because of personal preference and have no benefit other than maintaining consistency throughout the code.</p>
1022  
1023      <ul>
1024          <li>
1025              <p>Use <code>sizeof</code> instead of <code>count</code></p>
1026          </li>
1027          <li>
1028              <p>Use <code>strpos</code> instead of <code>strstr</code></p>
1029          </li>
1030          <li>
1031              <p>Use <code>else if</code> instead of <code>elseif</code></p>
1032          </li>
1033          <li>
1034              <p>Use <code>false</code> (lowercase) instead of <code>FALSE</code></p>
1035          </li>
1036          <li>
1037              <p>Use <code>true</code> (lowercase) instead of <code>TRUE</code></p>
1038          </li>
1039      </ul>
1040  
1041      <h4>Exiting</h4>
1042  
1043      <p>Your page should either call <code>page_footer()</code> in the end to trigger output through the template engine and terminate the script, or alternatively at least call the <code>exit_handler()</code>. That call is necessary because it provides a method for external applications embedding phpBB to be called at the end of the script.</p>
1044  
1045          </div>
1046  
1047          <div class="back2top"><a href="#wrap" class="top">Back to Top</a></div>
1048  
1049          <span class="corners-bottom"><span></span></span></div>
1050      </div>
1051  
1052      <hr />
1053  
1054  <a name="styling"></a><h2>3. Styling</h2>
1055      <div class="paragraph">
1056          <div class="inner"><span class="corners-top"><span></span></span>
1057  
1058          <div class="content">
1059      <a name="cfgfiles"></a><h3>3.i. Style Config Files</h3>
1060      <p>Style cfg files are simple name-value lists with the information necessary for installing a style. Similar cfg files exist for templates, themes and imagesets. These follow the same principle and will not be introduced individually. Styles can use installed components by using the required_theme/required_template/required_imageset entries. The important part of the style configuration file is assigning an unique name.</p>
1061      <div class="codebox"><pre>
1062          # General Information about this style
1063          name = prosilver_duplicate
1064          copyright = &copy; phpBB Group, 2007
1065          version = 3.0.3
1066          required_template = prosilver
1067          required_theme = prosilver
1068          required_imageset = prosilver
1069      </pre></div>
1070      <a name="genstyling"></a><h3>3.2. General Styling Rules</h3>
1071  <p>Templates should be produced in a consistent manner. Where appropriate they should be based off an existing copy, e.g. index, viewforum or viewtopic (the combination of which implement a range of conditional and variable forms). Please also note that the indentation and coding guidelines also apply to templates where possible.</p>
1072  
1073  <p>The outer table class <code>forumline</code> has gone and is replaced with <code>tablebg</code>.</p>
1074  <p>When writing <code>&lt;table&gt;</code> the order <code>&lt;table class="" cellspacing="" cellpadding="" border="" align=""&gt;</code> creates consistency and allows everyone to easily see which table produces which "look". The same applies to most other tags for which additional parameters can be set, consistency is the major aim here.</p>
1075  <p>Each block level element should be indented by one tab, same for tabular elements, e.g. <code>&lt;tr&gt;</code> <code>&lt;td&gt;</code> etc., whereby the intendiation of <code>&lt;table&gt;</code> and the following/ending <code>&lt;tr&gt;</code> should be on the same line. This applies not to div elements of course.</p>
1076  <p>Don't use <code>&lt;span&gt;</code> more than is essential ... the CSS is such that text sizes are dependent on the parent class. So writing <code>&lt;span class="gensmall"&gt;&lt;span class="gensmall"&gt;TEST&lt;/span&gt;&lt;/span&gt;</code> will result in very very small text. Similarly don't use span at all if another element can contain the class definition, e.g.</p>
1077  
1078  <div class="codebox"><pre>
1079  &lt;td&gt;&lt;span class=&quot;gensmall&quot;&gt;TEST&lt;/span&gt;&lt;/td&gt;
1080  </pre></div>
1081  
1082  <p>can just as well become:</p>
1083  <div class="codebox"><pre>
1084  &lt;td class=&quot;gensmall&quot;&gt;TEST&lt;/td&gt;
1085  </pre></div>
1086  
1087  <p>Try to match text class types with existing useage, e.g. don't use the nav class where viewtopic uses gensmall for example.</p>
1088  
1089  <p>Row colours/classes are now defined by the template, use an <code>IF S_ROW_COUNT</code> switch, see viewtopic or viewforum for an example.</p>
1090  
1091  <p>Remember block level ordering is important ... while not all pages validate as XHTML 1.0 Strict compliant it is something we're trying to work on.</p>
1092  
1093  <p>Use a standard cellpadding of 2 and cellspacing of 0 on outer tables. Inner tables can vary from 0 to 3 or even 4 depending on the need.</p>
1094  
1095  <p><strong>Use div container/css for styling and table for data representation.</strong></p>
1096  
1097  <p>The separate catXXXX and thXXX classes are gone. When defining a header cell just use <code>&lt;th&gt;</code> rather than <code>&lt;th class="thHead"&gt;</code> etc. Similarly for cat, don't use <code>&lt;td class="catLeft"&gt;</code> use <code>&lt;td class="cat"&gt;</code> etc.</p>
1098  
1099  <p>Try to retain consistency of basic layout and class useage, i.e. _EXPLAIN text should generally be placed below the title it explains, e.g. <code>{L_POST_USERNAME}&lt;br /&gt;&lt;span class="gensmall"&gt;{L_POST_USERNAME_EXPLAIN}&lt;/span&gt;</code> is the typical way of handling this ... there may be exceptions and this isn't a hard and fast rule.</p>
1100  
1101  <p>Try to keep template conditional and other statements tabbed in line with the block to which they refer.</p>
1102  
1103  <p class="good">this is correct</p>
1104  <div class="codebox"><pre>
1105  <span class="comment">&lt;!-- BEGIN test --&gt;</span>
1106      &lt;tr&gt;
1107          &lt;td&gt;&#123;test.TEXT&#125;&lt;/td&gt;
1108      &lt;/tr&gt;
1109  <span class="comment">&lt;!-- END test --&gt;</span>
1110  </pre></div>
1111  
1112  <p class="good">this is also correct:</p>
1113  <div class="codebox"><pre>
1114  <span class="comment">&lt;!-- BEGIN test --&gt;</span>
1115  &lt;tr&gt;
1116      &lt;td&gt;&#123;test.TEXT&#125;&lt;/td&gt;
1117  &lt;/tr&gt;
1118  <span class="comment">&lt;!-- END test --&gt;</span>
1119  </pre></div>
1120  
1121  <p>it gives immediate feedback on exactly what is looping - decide which way to use based on the readability.</p>
1122  
1123          </div>
1124  
1125          <div class="back2top"><a href="#wrap" class="top">Back to Top</a></div>
1126  
1127          <span class="corners-bottom"><span></span></span></div>
1128      </div>
1129  
1130      <hr />
1131  
1132  <a name="templating"></a><h2>4. Templating</h2>
1133      <div class="paragraph">
1134          <div class="inner"><span class="corners-top"><span></span></span>
1135  
1136          <div class="content">
1137      <a name="templates"></a><h3>4.i. General Templating</h3>
1138  
1139  <h4>File naming</h4>
1140  <p>Firstly templates now take the suffix &quot;.html&quot; rather than &quot;.tpl&quot;. This was done simply to make the lives of some people easier wrt syntax highlighting, etc.</p>
1141  
1142  <h4>Variables</h4>
1143  <p>All template variables should be named appropriately (using underscores for spaces), language entries should be prefixed with L_, system data with S_, urls with U_, javascript urls with UA_, language to be put in javascript statements with LA_, all other variables should be presented 'as is'.</p>
1144  
1145  <p>L_* template variables are automatically mapped to the corresponding language entry if the code does not set (and therefore overwrite) this variable specifically and if the language entry exists. For example <code>{L_USERNAME}</code> maps to <code>$user-&gt;lang['USERNAME']</code>. The LA_* template variables are handled within the same way, but properly escaped so they can be put in javascript code. This should reduce the need to assign loads of new language variables in MODifications.
1146  </p>
1147  
1148  <h4>Blocks/Loops</h4>
1149  <p>The basic block level loop remains and takes the form:</p>
1150  <div class="codebox"><pre>
1151  <span class="comment">&lt;!-- BEGIN loopname --&gt;</span>
1152      markup, {loopname&#46;X_YYYYY}, etc&#46;
1153  <span class="comment">&lt;!-- END loopname --&gt;</span>
1154  </pre></div>
1155  
1156  <p>A bit later loops will be explained further. To not irritate you we will explain conditionals as well as other statements first.</p>
1157  
1158  <h4>Including files</h4>
1159  <p>Something that existed in 2.0.x which no longer exists in 3.0.x is the ability to assign a template to a variable. This was used (for example) to output the jumpbox. Instead (perhaps better, perhaps not but certainly more flexible) we now have INCLUDE. This takes the simple form:</p>
1160  
1161  <div class="codebox"><pre>
1162  <span class="comment">&lt;!-- INCLUDE filename --&gt;</span>
1163  </pre></div>
1164  
1165  <p>You will note in the 3.0 templates the major sources start with <code>&lt;!-- INCLUDE overall_header.html --&gt;</code> or <code>&lt;!-- INCLUDE simple_header.html --&gt;</code>, etc. In 2.0.x control of &quot;which&quot; header to use was defined entirely within the code. In 3.0.x the template designer can output what they like. Note that you can introduce new templates (i.e. other than those in the default set) using this system and include them as you wish ... perhaps useful for a common &quot;menu&quot; bar or some such. No need to modify loads of files as with 2.0.x.</p>
1166  
1167  <p>Added in <strong>3.0.6</strong> is the ability to include a file using a template variable to specify the file, this functionality only works for root variables (i.e. not block variables).</p>
1168  <div class="codebox"><pre>
1169  <span class="comment">&lt;!-- INCLUDE {FILE_VAR} --&gt;</span>
1170  </pre></div>
1171  
1172  <p>Template defined variables can also be utilised.</p>
1173  
1174  <div class="codebox"><pre>
1175  <span class="comment">&lt;!-- DEFINE $SOME_VAR = 'my_file.html' --&gt;</span>
1176  <span class="comment">&lt;!-- INCLUDE {$SOME_VAR} --&gt;</span>
1177  </pre></div>
1178  
1179  <h4>PHP</h4>
1180  <p>A contentious decision has seen the ability to include PHP within the template introduced. This is achieved by enclosing the PHP within relevant tags:</p>
1181  
1182  <div class="codebox"><pre>
1183  <span class="comment">&lt;!-- PHP --&gt;</span>
1184      echo &quot;hello!&quot;;
1185  <span class="comment">&lt;!-- ENDPHP --&gt;</span>
1186  </pre></div>
1187  
1188  <p>You may also include PHP from an external file using:</p>
1189  
1190  <div class="codebox"><pre>
1191  <span class="comment">&lt;!-- INCLUDEPHP somefile&#46;php --&gt;</span>
1192  </pre></div>
1193  
1194  <p>it will be included and executed inline.<br /><br />A note, it is very much encouraged that template designers do not include PHP. The ability to include raw PHP was introduced primarily to allow end users to include banner code, etc. without modifying multiple files (as with 2.0.x). It was not intended for general use ... hence <!-- w --><a href="https://www.phpbb.com">www.phpbb.com</a><!-- w --> will <strong>not</strong> make available template sets which include PHP. And by default templates will have PHP disabled (the admin will need to specifically activate PHP for a template).</p>
1195  
1196  <h4>Conditionals/Control structures</h4>
1197  <p>The most significant addition to 3.0.x are conditions or control structures, &quot;if something then do this else do that&quot;. The system deployed is very similar to Smarty. This may confuse some people at first but it offers great potential and great flexibility with a little imagination. In their most simple form these constructs take the form:</p>
1198  
1199  <div class="codebox"><pre>
1200  <span class="comment">&lt;!-- IF expr --&gt;</span>
1201      markup
1202  <span class="comment">&lt;!-- ENDIF --&gt;</span>
1203  </pre></div>
1204  
1205  <p>expr can take many forms, for example:</p>
1206  
1207  <div class="codebox"><pre>
1208  <span class="comment">&lt;!-- IF loop&#46;S_ROW_COUNT is even --&gt;</span>
1209      markup
1210  <span class="comment">&lt;!-- ENDIF --&gt;</span>
1211  </pre></div>
1212  
1213  <p>This will output the markup if the S_ROW_COUNT variable in the current iteration of loop is an even value (i.e. the expr is TRUE). You can use various comparison methods (standard as well as equivalent textual versions noted in square brackets) including (<code>not, or, and, eq, neq, is</code> should be used if possible for better readability):</p>
1214  
1215  <div class="codebox"><pre>
1216  == [eq]
1217  != [neq, ne]
1218  &lt;&gt; (same as !=)
1219  !== (not equivalent in value and type)
1220  === (equivalent in value and type)
1221  &gt; [gt]
1222  &lt; [lt]
1223  &gt;= [gte]
1224  &lt;= [lte]
1225  &amp;&amp; [and]
1226  || [or]
1227  % [mod]
1228  ! [not]
1229  +
1230  -
1231  *
1232  /
1233  ,
1234  &lt;&lt; (bitwise shift left)
1235  &gt;&gt; (bitwise shift right)
1236  | (bitwise or)
1237  ^ (bitwise xor)
1238  &amp; (bitwise and)
1239  ~ (bitwise not)
1240  is (can be used to join comparison operations)
1241  </pre></div>
1242  
1243  <p>Basic parenthesis can also be used to enforce good old BODMAS rules. Additionally some basic comparison types are defined:</p>
1244  
1245  <div class="codebox"><pre>
1246  even
1247  odd
1248  div
1249  </pre></div>
1250  
1251  <p>Beyond the simple use of IF you can also do a sequence of comparisons using the following:</p>
1252  
1253  <div class="codebox"><pre>
1254  <span class="comment">&lt;!-- IF expr1 --&gt;</span>
1255      markup
1256  <span class="comment">&lt;!-- ELSEIF expr2 --&gt;</span>
1257      markup
1258      &#46;
1259      &#46;
1260      &#46;
1261  <span class="comment">&lt;!-- ELSEIF exprN --&gt;</span>
1262      markup
1263  <span class="comment">&lt;!-- ELSE --&gt;</span>
1264      markup
1265  <span class="comment">&lt;!-- ENDIF --&gt;</span>
1266  </pre></div>
1267  
1268  <p>Each statement will be tested in turn and the relevant output generated when a match (if a match) is found. It is not necessary to always use ELSEIF, ELSE can be used alone to match &quot;everything else&quot;.<br /><br />So what can you do with all this? Well take for example the colouration of rows in viewforum. In 2.0.x row colours were predefined within the source as either row color1, row color2 or row class1, row class2. In 3.0.x this is moved to the template, it may look a little daunting at first but remember control flows from top to bottom and it's not too difficult:</p>
1269  
1270  <div class="codebox"><pre>
1271  &lt;table&gt;
1272      <span class="comment">&lt;!-- IF loop&#46;S_ROW_COUNT is even --&gt;</span>
1273          &lt;tr class=&quot;row1&quot;&gt;
1274      <span class="comment">&lt;!-- ELSE --&gt;</span>
1275          &lt;tr class=&quot;row2&quot;&gt;
1276      <span class="comment">&lt;!-- ENDIF --&gt;</span>
1277      &lt;td&gt;HELLO!&lt;/td&gt;
1278  &lt;/tr&gt;
1279  &lt;/table&gt;
1280  </pre></div>
1281  
1282  <p>This will cause the row cell to be output using class row1 when the row count is even, and class row2 otherwise. The S_ROW_COUNT parameter gets assigned to loops by default. Another example would be the following: </p>
1283  
1284  <div class="codebox"><pre>
1285  &lt;table&gt;
1286      <span class="comment">&lt;!-- IF loop&#46;S_ROW_COUNT &gt; 10 --&gt;</span>
1287          &lt;tr bgcolor=&quot;#FF0000&quot;&gt;
1288      <span class="comment">&lt;!-- ELSEIF loop&#46;S_ROW_COUNT &gt; 5 --&gt;</span>
1289          &lt;tr bgcolor=&quot;#00FF00&quot;&gt;
1290      <span class="comment">&lt;!-- ELSEIF loop&#46;S_ROW_COUNT &gt; 2 --&gt;</span>
1291          &lt;tr bgcolor=&quot;#0000FF&quot;&gt;
1292      <span class="comment">&lt;!-- ELSE --&gt;</span>
1293          &lt;tr bgcolor=&quot;#FF00FF&quot;&gt;
1294      <span class="comment">&lt;!-- ENDIF --&gt;</span>
1295      &lt;td&gt;hello!&lt;/td&gt;
1296  &lt;/tr&gt;
1297  &lt;/table&gt;
1298  </pre></div>
1299  
1300  <p>This will output the row cell in purple for the first two rows, blue for rows 2 to 5, green for rows 5 to 10 and red for remainder. So, you could produce a &quot;nice&quot; gradient effect, for example.<br /><br />What else can you do? Well, you could use IF to do common checks on for example the login state of a user:</p>
1301  
1302  <div class="codebox"><pre>
1303  <span class="comment">&lt;!-- IF S_USER_LOGGED_IN --&gt;</span>
1304      markup
1305  <span class="comment">&lt;!-- ENDIF --&gt;</span>
1306  </pre></div>
1307  
1308  <p>This replaces the existing (fudged) method in 2.0.x using a zero length array and BEGIN/END.</p>
1309  
1310  <h4>Extended syntax for Blocks/Loops</h4>
1311  
1312  <p>Back to our loops - they had been extended with the following additions. Firstly you can set the start and end points of the loop. For example:</p>
1313  
1314  <div class="codebox"><pre>
1315  <span class="comment">&lt;!-- BEGIN loopname(2) --&gt;</span>
1316      markup
1317  <span class="comment">&lt;!-- END loopname --&gt;</span>
1318  </pre></div>
1319  
1320  <p>Will start the loop on the third entry (note that indexes start at zero). Extensions of this are:
1321  <br /><br />
1322  <code>loopname(2)</code>: Will start the loop on the 3rd entry<br />
1323  <code>loopname(-2)</code>: Will start the loop two entries from the end<br />
1324  <code>loopname(3,4)</code>: Will start the loop on the fourth entry and end it on the fifth<br />
1325  <code>loopname(3,-4)</code>: Will start the loop on the fourth entry and end it four from last<br />
1326  </p>
1327  
1328  <p>A further extension to begin is BEGINELSE:</p>
1329  
1330  <div class="codebox"><pre>
1331  <span class="comment">&lt;!-- BEGIN loop --&gt;</span>
1332      markup
1333  <span class="comment">&lt;!-- BEGINELSE --&gt;</span>
1334      markup
1335  <span class="comment">&lt;!-- END loop --&gt;</span>
1336  </pre></div>
1337  
1338  <p>This will cause the markup between <code>BEGINELSE</code> and <code>END</code> to be output if the loop contains no values. This is useful for forums with no topics (for example) ... in some ways it replaces &quot;bits of&quot; the existing &quot;switch_&quot; type control (the rest being replaced by conditionals).</p>
1339  
1340  <p>Another way of checking if a loop contains values is by prefixing the loops name with a dot:</p>
1341  
1342  <div class="codebox"><pre>
1343  <span class="comment">&lt;!-- IF .loop --&gt;</span>
1344      <span class="comment">&lt;!-- BEGIN loop --&gt;</span>
1345          markup
1346      <span class="comment">&lt;!-- END loop --&gt;</span>
1347  <span class="comment">&lt;!-- ELSE --&gt;</span>
1348      markup
1349  <span class="comment">&lt;!-- ENDIF --&gt;</span>
1350  </pre></div>
1351  
1352  <p>You are even able to check the number of items within a loop by comparing it with values within the IF condition:</p>
1353  
1354  <div class="codebox"><pre>
1355  <span class="comment">&lt;!-- IF .loop &gt; 2 --&gt;</span>
1356      <span class="comment">&lt;!-- BEGIN loop --&gt;</span>
1357          markup
1358      <span class="comment">&lt;!-- END loop --&gt;</span>
1359  <span class="comment">&lt;!-- ELSE --&gt;</span>
1360      markup
1361  <span class="comment">&lt;!-- ENDIF --&gt;</span>
1362  </pre></div>
1363  
1364  <p>Nesting loops cause the conditionals needing prefixed with all loops from the outer one to the inner most. An illustration of this:</p>
1365  
1366  <div class="codebox"><pre>
1367  <span class="comment">&lt;!-- BEGIN firstloop --&gt;</span>
1368      {firstloop.MY_VARIABLE_FROM_FIRSTLOOP}
1369  
1370      <span class="comment">&lt;!-- BEGIN secondloop --&gt;</span>
1371          {firstloop.secondloop.MY_VARIABLE_FROM_SECONDLOOP}
1372      <span class="comment">&lt;!-- END secondloop --&gt;</span>
1373  <span class="comment">&lt;!-- END firstloop --&gt;</span>
1374  </pre></div>
1375  
1376  <p>Sometimes it is necessary to break out of nested loops to be able to call another loop within the current iteration. This sounds a little bit confusing and it is not used very often. The following (rather complex) example shows this quite good - it also shows how you test for the first and last row in a loop (i will explain the example in detail further down):</p>
1377  
1378  <div class="codebox"><pre>
1379  <span class="comment">&lt;!-- BEGIN l_block1 --&gt;</span>
1380      <span class="comment">&lt;!-- IF l_block1.S_SELECTED --&gt;</span>
1381          &lt;strong&gt;{l_block1.L_TITLE}&lt;/strong&gt;
1382          <span class="comment">&lt;!-- IF S_PRIVMSGS --&gt;</span>
1383  
1384              <span class="comment">&lt;!-- the ! at the beginning of the loop name forces the loop to be not a nested one of l_block1 --&gt;</span>
1385              <span class="comment">&lt;!-- BEGIN !folder --&gt;</span>
1386                  <span class="comment">&lt;!-- IF folder.S_FIRST_ROW --&gt;</span>
1387                      &lt;ul class=&quot;nav&quot;&gt;
1388                  <span class="comment">&lt;!-- ENDIF --&gt;</span>
1389  
1390                  &lt;li&gt;&lt;a href=&quot;{folder.U_FOLDER}&quot;&gt;{folder.FOLDER_NAME}&lt;/a&gt;&lt;/li&gt;
1391  
1392                  <span class="comment">&lt;!-- IF folder.S_LAST_ROW --&gt;</span>
1393                      &lt;/ul&gt;
1394                  <span class="comment">&lt;!-- ENDIF --&gt;</span>
1395              <span class="comment">&lt;!-- END !folder --&gt;</span>
1396  
1397          <span class="comment">&lt;!-- ENDIF --&gt;</span>
1398  
1399          &lt;ul class=&quot;nav&quot;&gt;
1400          <span class="comment">&lt;!-- BEGIN l_block2 --&gt;</span>
1401              &lt;li&gt;
1402                  <span class="comment">&lt;!-- IF l_block1.l_block2.S_SELECTED --&gt;</span>
1403                      &lt;strong&gt;{l_block1.l_block2.L_TITLE}&lt;/strong&gt;
1404                  <span class="comment">&lt;!-- ELSE --&gt;</span>
1405                      &lt;a href=&quot;{l_block1.l_block2.U_TITLE}&quot;&gt;{l_block1.l_block2.L_TITLE}&lt;/a&gt;
1406                  <span class="comment">&lt;!-- ENDIF --&gt;</span>
1407              &lt;/li&gt;
1408          <span class="comment">&lt;!-- END l_block2 --&gt;</span>
1409          &lt;/ul&gt;
1410      <span class="comment">&lt;!-- ELSE --&gt;</span>
1411          &lt;a class=&quot;nav&quot; href=&quot;{l_block1.U_TITLE}&quot;&gt;{l_block1.L_TITLE}&lt;/a&gt;
1412      <span class="comment">&lt;!-- ENDIF --&gt;</span>
1413  <span class="comment">&lt;!-- END l_block1 --&gt;</span>
1414  </pre></div>
1415  
1416  <p>Let us first concentrate on this part of the example:</p>
1417  
1418  <div class="codebox"><pre>
1419  <span class="comment">&lt;!-- BEGIN l_block1 --&gt;</span>
1420      <span class="comment">&lt;!-- IF l_block1.S_SELECTED --&gt;</span>
1421          markup
1422      <span class="comment">&lt;!-- ELSE --&gt;</span>
1423          &lt;a class=&quot;nav&quot; href=&quot;{l_block1.U_TITLE}&quot;&gt;{l_block1.L_TITLE}&lt;/a&gt;
1424      <span class="comment">&lt;!-- ENDIF --&gt;</span>
1425  <span class="comment">&lt;!-- END l_block1 --&gt;</span>
1426  </pre></div>
1427  
1428  <p>Here we open the loop l_block1 and do some things if the value S_SELECTED within the current loop iteration is true, else we write the blocks link and title. Here, you see <code>{l_block1.L_TITLE}</code> referenced - you remember that L_* variables get automatically assigned the corresponding language entry? This is true, but not within loops. The L_TITLE variable within the loop l_block1 is assigned within the code itself.</p>
1429  
1430  <p>Let's have a closer look at the markup:</p>
1431  
1432  <div class="codebox"><pre>
1433  <span class="comment">&lt;!-- BEGIN l_block1 --&gt;</span>
1434  .
1435  .
1436      <span class="comment">&lt;!-- IF S_PRIVMSGS --&gt;</span>
1437  
1438          <span class="comment">&lt;!-- BEGIN !folder --&gt;</span>
1439              <span class="comment">&lt;!-- IF folder.S_FIRST_ROW --&gt;</span>
1440                  &lt;ul class=&quot;nav&quot;&gt;
1441              <span class="comment">&lt;!-- ENDIF --&gt;</span>
1442  
1443              &lt;li&gt;&lt;a href=&quot;{folder.U_FOLDER}&quot;&gt;{folder.FOLDER_NAME}&lt;/a&gt;&lt;/li&gt;
1444  
1445              <span class="comment">&lt;!-- IF folder.S_LAST_ROW --&gt;</span>
1446                  &lt;/ul&gt;
1447              <span class="comment">&lt;!-- ENDIF --&gt;</span>
1448          <span class="comment">&lt;!-- END !folder --&gt;</span>
1449  
1450      <span class="comment">&lt;!-- ENDIF --&gt;</span>
1451  .
1452  .
1453  <span class="comment">&lt;!-- END l_block1 --&gt;</span>
1454  </pre></div>
1455  
1456  <p>The <code>&lt;!-- IF S_PRIVMSGS --&gt;</code> statement clearly checks a global variable and not one within the loop, since the loop is not given here. So, if S_PRIVMSGS is true we execute the shown markup. Now, you see the <code>&lt;!-- BEGIN !folder --&gt;</code> statement. The exclamation mark is responsible for instructing the template engine to iterate through the main loop folder. So, we are now within the loop folder - with <code>&lt;!-- BEGIN folder --&gt;</code> we would have been within the loop <code>l_block1.folder</code> automatically as is the case with l_block2:</p>
1457  
1458  <div class="codebox"><pre>
1459  <span class="comment">&lt;!-- BEGIN l_block1 --&gt;</span>
1460  .
1461  .
1462      &lt;ul class=&quot;nav&quot;&gt;
1463      <span class="comment">&lt;!-- BEGIN l_block2 --&gt;</span>
1464          &lt;li&gt;
1465              <span class="comment">&lt;!-- IF l_block1.l_block2.S_SELECTED --&gt;</span>
1466                  &lt;strong&gt;{l_block1.l_block2.L_TITLE}&lt;/strong&gt;
1467              <span class="comment">&lt;!-- ELSE --&gt;</span>
1468                  &lt;a href=&quot;{l_block1.l_block2.U_TITLE}&quot;&gt;{l_block1.l_block2.L_TITLE}&lt;/a&gt;
1469              <span class="comment">&lt;!-- ENDIF --&gt;</span>
1470          &lt;/li&gt;
1471      <span class="comment">&lt;!-- END l_block2 --&gt;</span>
1472      &lt;/ul&gt;
1473  .
1474  .
1475  <span class="comment">&lt;!-- END l_block1 --&gt;</span>
1476  </pre></div>
1477  
1478  <p>You see the difference? The loop l_block2 is a member of the loop l_block1 but the loop folder is a main loop.</p>
1479  
1480  <p>Now back to our folder loop:</p>
1481  
1482  <div class="codebox"><pre>
1483  <span class="comment">&lt;!-- IF folder.S_FIRST_ROW --&gt;</span>
1484      &lt;ul class=&quot;nav&quot;&gt;
1485  <span class="comment">&lt;!-- ENDIF --&gt;</span>
1486  
1487  &lt;li&gt;&lt;a href=&quot;{folder.U_FOLDER}&quot;&gt;{folder.FOLDER_NAME}&lt;/a&gt;&lt;/li&gt;
1488  
1489  <span class="comment">&lt;!-- IF folder.S_LAST_ROW --&gt;</span>
1490      &lt;/ul&gt;
1491  <span class="comment">&lt;!-- ENDIF --&gt;</span>
1492  </pre></div>
1493  
1494  <p>You may have wondered what the comparison to S_FIRST_ROW and S_LAST_ROW is about. If you haven't guessed already - it is checking for the first iteration of the loop with <code>S_FIRST_ROW</code> and the last iteration with <code>S_LAST_ROW</code>. This can come in handy quite often if you want to open or close design elements, like the above list. Let us imagine a folder loop build with three iterations, it would go this way:</p>
1495  
1496  <div class="codebox"><pre>
1497  &lt;ul class=&quot;nav&quot;&gt; <span class="comment">&lt;!-- written on first iteration --&gt;</span>
1498      &lt;li&gt;first element&lt;/li&gt; <span class="comment">&lt;!-- written on first iteration --&gt;</span>
1499      &lt;li&gt;second element&lt;/li&gt; <span class="comment">&lt;!-- written on second iteration --&gt;</span>
1500      &lt;li&gt;third element&lt;/li&gt; <span class="comment">&lt;!-- written on third iteration --&gt;</span>
1501  &lt;/ul&gt; <span class="comment">&lt;!-- written on third iteration --&gt;</span>
1502  </pre></div>
1503  
1504  <p>As you can see, all three elements are written down as well as the markup for the first iteration and the last one. Sometimes you want to omit writing the general markup - for example:</p>
1505  
1506  <div class="codebox"><pre>
1507  <span class="comment">&lt;!-- IF folder.S_FIRST_ROW --&gt;</span>
1508      &lt;ul class=&quot;nav&quot;&gt;
1509  <span class="comment">&lt;!-- ELSEIF folder.S_LAST_ROW --&gt;</span>
1510      &lt;/ul&gt;
1511  <span class="comment">&lt;!-- ELSE --&gt;</span>
1512      &lt;li&gt;&lt;a href=&quot;{folder.U_FOLDER}&quot;&gt;{folder.FOLDER_NAME}&lt;/a&gt;&lt;/li&gt;
1513  <span class="comment">&lt;!-- ENDIF --&gt;</span>
1514  </pre></div>
1515  
1516  <p>would result in the following markup:</p>
1517  
1518  <div class="codebox"><pre>
1519  &lt;ul class=&quot;nav&quot;&gt; <span class="comment">&lt;!-- written on first iteration --&gt;</span>
1520      &lt;li&gt;second element&lt;/li&gt; <span class="comment">&lt;!-- written on second iteration --&gt;</span>
1521  &lt;/ul&gt; <span class="comment">&lt;!-- written on third iteration --&gt;</span>
1522  </pre></div>
1523  
1524  <p>Just always remember that processing is taking place from top to bottom.</p>
1525  
1526      <h4>Forms</h4>
1527          <p>If a form is used for a non-trivial operation (i.e. more than a jumpbox), then it should include the <code>{S_FORM_TOKEN}</code> template variable.</p>
1528          <div class="codebox"><pre>
1529  &lt;form method=&quot;post&quot; id=&quot;mcp&quot; action=&quot;{U_POST_ACTION}&quot;&gt;
1530  
1531      &lt;fieldset class="submit-buttons"&gt;
1532          &lt;input type=&quot;reset&quot; value=&quot;{L_RESET}&quot; name=&quot;reset&quot; class=&quot;button2&quot; /&gt;&nbsp;
1533          &lt;input type=&quot;submit&quot; name=&quot;action[add_warning]&quot; value=&quot;{L_SUBMIT}&quot; class=&quot;button1&quot; /&gt;
1534          {S_FORM_TOKEN}
1535      &lt;/fieldset&gt;
1536  &lt;/form&gt;
1537          </pre></div><br />
1538  
1539      <a name="inheritance"></a><h3>4.ii. Template Inheritance</h3>
1540          <p>When basing a new style on an existing one, it is not necessary to provide all the template files. By declaring the base style name in the <strong>inherit_from</strong> field in the template configuration file, the style can be set to inherit template files from the base style. The limitation on this is that the base style has to be installed and complete, meaning that it is not itself inheriting.</p>
1541  
1542          <p>The effect of doing so is that the template engine will use the template files in the new style where they exist, but fall back to files in the base style otherwise. Declaring a style to inherit from another also causes it to use some of the configuration settings of the base style, notably database storage.</p>
1543  
1544          <p>We strongly encourage the use of inheritance for styles based on the bundled styles, as it will ease the update procedure.</p>
1545  
1546          <div class="codebox"><pre>
1547          # General Information about this template
1548          name = inherits
1549          copyright = &copy; phpBB Group, 2007
1550          version = 3.0.3
1551  
1552          # Defining a different template bitfield
1553          template_bitfield = lNg=
1554  
1555          # Are we inheriting?
1556          inherit_from = prosilver
1557          </pre></div>
1558  
1559          </div>
1560  
1561          <div class="back2top"><a href="#wrap" class="top">Back to Top</a></div>
1562  
1563          <span class="corners-bottom"><span></span></span></div>
1564      </div>
1565  
1566      <hr />
1567  
1568  
1569  
1570  <a name="charsets"></a><h2>5. Character Sets and Encodings</h2>
1571  
1572      <div class="paragraph">
1573          <div class="inner"><span class="corners-top"><span></span></span>
1574  
1575          <div class="content">
1576  
1577  
1578  
1579  <h4>What are Unicode, UCS and UTF-8?</h4>
1580  <p>The <a href="http://en.wikipedia.org/wiki/Universal_Character_Set">Universal Character Set (UCS)</a> described in ISO/IEC 10646 consists of a large amount of characters. Each of them has a unique name and a code point which is an integer number. <a href="http://en.wikipedia.org/wiki/Unicode">Unicode</a> - which is an industry standard - complements the Universal Character Set with further information about the characters' properties and alternative character encodings. More information on Unicode can be found on the <a href="http://www.unicode.org/">Unicode Consortium's website</a>. One of the Unicode encodings is the <a href="http://en.wikipedia.org/wiki/UTF-8">8-bit Unicode Transformation Format (UTF-8)</a>. It encodes characters with up to four bytes aiming for maximum compatibility with the <a href="http://en.wikipedia.org/wiki/ASCII">American Standard Code for Information Interchange</a> which is a 7-bit encoding of a relatively small subset of the UCS.</p>
1581  
1582  <h4>phpBB's use of Unicode</h4>
1583  <p>Unfortunately PHP does not faciliate the use of Unicode prior to version 6. Most functions simply treat strings as sequences of bytes assuming that each character takes up exactly one byte. This behaviour still allows for storing UTF-8 encoded text in PHP strings but many operations on strings have unexpected results. To circumvent this problem we have created some alternative functions to PHP's native string operations which use code points instead of bytes. These functions can be found in <code>/includes/utf/utf_tools.php</code>. They are also covered in the <a href="http://area51.phpbb.com/docs/code/">phpBB3 Sourcecode Documentation</a>. A lot of native PHP functions still work with UTF-8 as long as you stick to certain restrictions. For example <code>explode</code> still works as long as the first and the last character of the delimiter string are ASCII characters.</p>
1584  
1585  <p>phpBB only uses the ASCII and the UTF-8 character encodings. Still all Strings are UTF-8 encoded because ASCII is a subset of UTF-8. The only exceptions to this rule are code sections which deal with external systems which use other encodings and character sets. Such external data should be converted to UTF-8 using the <code>utf8_recode()</code> function supplied with phpBB. It supports a variety of other character sets and encodings, a full list can be found below.</p>
1586  
1587  <p>With <code>request_var()</code> you can either allow all UCS characters in user input or restrict user input to ASCII characters. This feature is controlled by the function's third parameter called <code>$multibyte</code>. You should allow multibyte characters in posts, PMs, topic titles, forum names, etc. but it's not necessary for internal uses like a <code>$mode</code> variable which should only hold a predefined list of ASCII strings anyway.</p>
1588  
1589  <div class="codebox"><pre>
1590  // an input string containing a multibyte character
1591  $_REQUEST['multibyte_string'] = 'K&#228;se';
1592  
1593  // print request variable as a UTF-8 string allowing multibyte characters
1594  echo request_var('multibyte_string', '', true);
1595  // print request variable as ASCII string
1596  echo request_var('multibyte_string', '');
1597  </pre></div>
1598  
1599  <p>This code snippet will generate the following output:</p>
1600  
1601  <div class="codebox"><pre>
1602  K&#228;se
1603  K??se
1604  </pre></div>
1605  
1606  <h4>Unicode Normalization</h4>
1607  
1608  <p>If you retrieve user input with multibyte characters you should additionally normalize the string using <code>utf8_normalize_nfc()</code> before you work with it. This is necessary to make sure that equal characters can only occur in one particular binary representation. For example the character &#197; can be represented either as <code>U+00C5</code> (LATIN CAPITAL LETTER A WITH RING ABOVE) or as <code>U+212B</code> (ANGSTROM SIGN). phpBB uses Normalization Form Canonical Composition (NFC) for all text. So the correct version of the above example would look like this:</p>
1609  
1610  <div class="codebox"><pre>
1611  $_REQUEST['multibyte_string'] = 'K&#228;se';
1612  
1613  // normalize multibyte strings
1614  echo utf8_normalize_nfc(request_var('multibyte_string', '', true));
1615  // ASCII strings do not need to be normalized
1616  echo request_var('multibyte_string', '');
1617  </pre></div>
1618  
1619  <h4>Case Folding</h4>
1620  
1621  <p>Case insensitive comparison of strings is no longer possible with <code>strtolower</code> or <code>strtoupper</code> as some characters have multiple lower case or multiple upper case forms depending on their position in a word. The <code>utf8_strtolower</code> and the <code>utf8_strtoupper</code> functions suffer from the same problem so they can only be used to display upper/lower case versions of a string but they cannot be used for case insensitive comparisons either. So instead you should use case folding which gives you a case insensitive version of the string which can be used for case insensitive comparisons. An NFC normalized string can be case folded using <code>utf8_case_fold_nfc()</code>.</p>
1622  
1623  <p class="bad">// Bad - The strings might be the same even if strtolower differs</p>
1624  
1625  <div class="codebox"><pre>
1626  if (strtolower($string1) == strtolower($string2))
1627  {
1628      echo '$string1 and $string2 are equal or differ in case';
1629  }
1630  </pre></div>
1631  
1632  <p class="good">// Good - Case folding is really case insensitive</p>
1633  
1634  <div class="codebox"><pre>
1635  if (utf8_case_fold_nfc($string1) == utf8_case_fold_nfc($string2))
1636  {
1637      echo '$string1 and $string2 are equal or differ in case';
1638  }
1639  </pre></div>
1640  
1641  <h4>Confusables Detection</h4>
1642  
1643  <p>phpBB offers a special method <code>utf8_clean_string</code> which can be used to make sure string identifiers are unique. This method uses Normalization Form Compatibility Composition (NFKC) instead of NFC and replaces similarly looking characters with a particular representative of the equivalence class. This method is currently used for usernames and group names to avoid confusion with similarly looking names.</p>
1644  
1645          </div>
1646  
1647          <div class="back2top"><a href="#wrap" class="top">Back to Top</a></div>
1648  
1649          <span class="corners-bottom"><span></span></span></div>
1650      </div>
1651  
1652      <hr />
1653  
1654  <a name="translation"></a><h2>6. Translation (<abbr title="Internationalisation">i18n</abbr>/<abbr title="Localisation">L10n</abbr>) Guidelines</h2>
1655  
1656      <div class="paragraph">
1657          <div class="inner"><span class="corners-top"><span></span></span>
1658  
1659          <div class="content">
1660  
1661      <a name="standardisation"></a><h3>6.i. Standardisation</h3>
1662  
1663      <h4>Reason:</h4>
1664  
1665      <p>phpBB is one of the most translated open-source projects, with the current stable version being available in over 60 localisations. Whilst the ad hoc approach to the naming of language packs has worked, for phpBB3 and beyond we hope to make this process saner which will allow for better interoperation with current and future web browsers.</p>
1666  
1667      <h4>Encoding:</h4>
1668  
1669      <p>With phpBB3, the output encoding for the forum in now UTF-8, a Universal Character Encoding by the Unicode Consortium that is by design a superset to US-ASCII and ISO-8859-1. By using one character set which simultaenously supports all scripts which previously would have required different encodings (eg: ISO-8859-1 to ISO-8859-15 (Latin, Greek, Cyrillic, Thai, Hebrew, Arabic); GB2312 (Simplified Chinese); Big5 (Traditional Chinese), EUC-JP (Japanese), EUC-KR (Korean), VISCII (Vietnamese); et cetera), we remove the need to convert between encodings and improves the accessibility of multilingual forums.</p>
1670  
1671      <p>The impact is that the language files for phpBB must now also be encoded as UTF-8, with a caveat that the files must <strong>not contain</strong> a <acronym title="Byte-Order-Mark">BOM</acronym> for compatibility reasons with non-Unicode aware versions of PHP. For those with forums using the Latin character set (ie: most European languages), this change is transparent since UTF-8 is superset to US-ASCII and ISO-8859-1.</p>
1672  
1673      <h4>Language Tag:</h4>
1674  
1675      <p>The <abbr title="Internet Engineering Task Force">IETF</abbr> recently published <a href="http://tools.ietf.org/html/rfc4646">RFC 4646</a> for tags used to identify languages, which in combination with <a href="http://tools.ietf.org/html/rfc4647">RFC 4647</a> obseletes the older <a href="http://tools.ietf.org/html/rfc3066">RFC 3006</a> and older-still <a href="http://tools.ietf.org/html/rfc1766">RFC 1766</a>. <a href="http://tools.ietf.org/html/rfc4646">RFC 4646</a> uses <a href="http://www.loc.gov/standards/iso639-2/php/English_list.php">ISO 639-1/ISO 639-2</a>, <a href="http://www.iso.ch/iso/en/prods-services/iso3166ma/02iso-3166-code-lists/list-en1.html">ISO 3166-1 alpha-2</a>, <a href="http://www.unicode.org/iso15924/iso15924-codes.html">ISO 15924</a> and <a href="http://unstats.un.org/unsd/methods/m49/m49.htm">UN M.49</a> to define a language tag. Each complete tag is composed of subtags which are not case sensitive and can also be empty.</p>
1676  
1677      <p>Ordering of the subtags in the case that they are all non-empty is: <code>language</code>-<code>script</code>-<code>region</code>-<code>variant</code>-<code>extension</code>-<code>privateuse</code>. Should any subtag be empty, its corresponding hyphen would also be ommited. Thus, the language tag for English will be <code>en</code> <strong>and not</strong> <code>en-----</code>.</p>
1678  
1679      <p>Most language tags consist of a two- or three-letter language subtag (from <a href="http://www.loc.gov/standards/iso639-2/php/English_list.php">ISO 639-1/ISO 639-2</a>). Sometimes, this is followed by a two-letter or three-digit region subtag (from <a href="http://www.iso.ch/iso/en/prods-services/iso3166ma/02iso-3166-code-lists/list-en1.html">ISO 3166-1 alpha-2</a> or <a href="http://unstats.un.org/unsd/methods/m49/m49.htm">UN M.49</a>). Some examples are:</p>
1680  
1681      <table summary="Examples of various possible language tags as described by RFC 4646 and RFC 4647">
1682      <caption>Language tag examples</caption>
1683      <thead>
1684      <tr>
1685          <th scope="col">Language tag</th>
1686          <th scope="col">Description</th>
1687          <th scope="col">Component subtags</th>
1688      </tr>
1689      </thead>
1690      <tbody>
1691      <tr>
1692          <td><code>en</code></td>
1693          <td>English</td>
1694          <td><code>language</code></td>
1695      </tr>
1696      <tr>
1697          <td><code>mas</code></td>
1698          <td>Masai</td>
1699          <td><code>language</code></td>
1700      </tr>
1701      <tr>
1702          <td><code>fr-CA</code></td>
1703          <td>French as used in Canada</td>
1704          <td><code>language</code>+<code>region</code></td>
1705      </tr>
1706      <tr>
1707          <td><code>en-833</code></td>
1708          <td>English as used in the Isle of Man</td>
1709          <td><code>language</code>+<code>region</code></td>
1710      </tr>
1711      <tr>
1712          <td><code>zh-Hans</code></td>
1713          <td>Chinese written with Simplified script</td>
1714          <td><code>language</code>+<code>script</code></td>
1715      </tr>
1716      <tr>
1717          <td><code>zh-Hant-HK</code></td>
1718          <td>Chinese written with Traditional script as used in Hong Kong</td>
1719          <td><code>language</code>+<code>script</code>+<code>region</code></td>
1720      </tr>
1721      <tr>
1722          <td><code>de-AT-1996</code></td>
1723          <td>German as used in Austria with 1996 orthography</td>
1724          <td><code>language</code>+<code>region</code>+<code>variant</code></td>
1725      </tr>
1726      </tbody>
1727      </table>
1728  
1729      <p>The ultimate aim of a language tag is to convey the needed <strong>useful distingushing information</strong>, whilst keeping it as <strong>short as possible</strong>. So for example, use <code>en</code>, <code>fr</code> and <code>ja</code> as opposed to <code>en-GB</code>, <code>fr-FR</code> and <code>ja-JP</code>, since we know English, French and Japanese are the native language of Great Britain, France and Japan respectively.</p>
1730  
1731      <p>Next is the <a href="http://www.unicode.org/iso15924/iso15924-codes.html">ISO 15924</a> language script code and when one should or shouldn't use it. For example, whilst <code>en-Latn</code> is syntaxically correct for describing English written with Latin script, real world English writing is <strong>more-or-less exclusively in the Latin script</strong>. For such languages like English that are written in a single script, the <a href="http://www.iana.org/assignments/language-subtag-registry"><abbr title="Internet Assigned Numbers Authority">IANA</abbr> Language Subtag Registry</a> has a "Suppress-Script" field meaning the script code <strong>should be ommitted</strong> unless a specific language tag requires a specific script code. Some languages are <strong>written in more than one script</strong> and in such cases, the script code <strong>is encouraged</strong> since an end-user may be able to read their language in one script, but not the other. Some examples are:</p>
1732  
1733      <table summary="Examples of using a language subtag in combination with a script subtag">
1734      <caption>Language subtag + script subtag examples</caption>
1735      <thead>
1736      <tr>
1737          <th scope="col">Language tag</th>
1738          <th scope="col">Description</th>
1739          <th scope="col">Component subtags</th>
1740      </tr>
1741      </thead>
1742      <tbody>
1743      <tr>
1744          <td><code>en-Brai</code></td>
1745          <td>English written in Braille script</td>
1746          <td><code>language</code>+<code>script</code></td>
1747      </tr>
1748      <tr>
1749          <td><code>en-Dsrt</code></td>
1750          <td>English written in Deseret (Mormon) script</td>
1751          <td><code>language</code>+<code>script</code></td>
1752      </tr>
1753      <tr>
1754          <td><code>sr-Latn</code></td>
1755          <td>Serbian written in Latin script</td>
1756          <td><code>language</code>+<code>script</code></td>
1757      </tr>
1758      <tr>
1759          <td><code>sr-Cyrl</code></td>
1760          <td>Serbian written in Cyrillic script</td>
1761          <td><code>language</code>+<code>script</code></td>
1762      </tr>
1763      <tr>
1764          <td><code>mn-Mong</code></td>
1765          <td>Mongolian written in Mongolian script</td>
1766          <td><code>language</code>+<code>script</code></td>
1767      </tr>
1768      <tr>
1769          <td><code>mn-Cyrl</code></td>
1770          <td>Mongolian written in Cyrillic script</td>
1771          <td><code>language</code>+<code>script</code></td>
1772      </tr>
1773      <tr>
1774          <td><code>mn-Phag</code></td>
1775          <td>Mongolian written in Phags-pa script</td>
1776          <td><code>language</code>+<code>script</code></td>
1777      </tr>
1778      <tr>
1779          <td><code>az-Cyrl-AZ</code></td>
1780          <td>Azerbaijani written in Cyrillic script as used in Azerbaijan</td>
1781          <td><code>language</code>+<code>script</code>+<code>region</code></td>
1782      </tr>
1783      <tr>
1784          <td><code>az-Latn-AZ</code></td>
1785          <td>Azerbaijani written in Latin script as used in Azerbaijan</td>
1786          <td><code>language</code>+<code>script</code>+<code>region</code></td>
1787      </tr>
1788      <tr>
1789          <td><code>az-Arab-IR</code></td>
1790          <td>Azerbaijani written in Arabic script as used in Iran</td>
1791          <td><code>language</code>+<code>script</code>+<code>region</code></td>
1792      </tr>
1793      </tbody>
1794      </table>
1795  
1796      <p>Usage of the three-digit <a href="http://unstats.un.org/unsd/methods/m49/m49.htm">UN M.49</a> code over the two-letter <a href="http://www.iso.ch/iso/en/prods-services/iso3166ma/02iso-3166-code-lists/list-en1.html">ISO 3166-1 alpha-2</a> code should hapen if a macro-geographical entity is required and/or the <a href="http://www.iso.ch/iso/en/prods-services/iso3166ma/02iso-3166-code-lists/list-en1.html">ISO 3166-1 alpha-2</a> is ambiguous.</p>
1797  
1798      <p>Examples of English using marco-geographical regions:</p>
1799  
1800      <table summary="Examples for English of ISO 3166-1 alpha-2 vs. UN M.49 code">
1801      <caption>Coding for English using macro-geographical regions</caption>
1802      <thead>
1803      <tr>
1804          <th scope="col">ISO 639-1/ISO 639-2 + ISO 3166-1 alpha-2</th>
1805          <th scope="col" colspan="2">ISO 639-1/ISO 639-2 + UN M.49 (Example macro regions)</th>
1806      </tr>
1807      </thead>
1808      <tbody>
1809      <tr>
1810          <td><dl><dt><code>en-AU</code></dt><dd>English as used in <strong>Australia</strong></dd></dl></td>
1811          <td rowspan="2"><dl><dt><code>en-053</code></dt><dd>English as used in <strong>Australia &amp; New Zealand</strong></dd></dl></td>
1812          <td rowspan="3"><dl><dt><code>en-009</code></dt><dd>English as used in <strong>Oceania</strong></dd></dl></td>
1813      </tr>
1814      <tr>
1815          <td><dl><dt><code>en-NZ</code></dt><dd>English as used in <strong>New Zealand</strong></dd></dl></td>
1816      </tr>
1817      <tr>
1818          <td><dl><dt><code>en-FJ</code></dt><dd>English as used in <strong>Fiji</strong></dd></dl></td>
1819          <td><dl><dt><code>en-054 </code></dt><dd>English as used in <strong>Melanesia</strong></dd></dl></td>
1820      </tr>
1821      </tbody>
1822      </table>
1823  
1824      <p>Examples of Spanish using marco-geographical regions:</p>
1825  
1826      <table summary="Examples for Spanish of ISO 3166-1 alpha-2 vs. UN M.49 code">
1827      <caption>Coding for Spanish macro-geographical regions</caption>
1828      <thead>
1829      <tr>
1830          <th scope="col">ISO 639-1/ISO 639-2 + ISO 3166-1 alpha-2</th>
1831          <th scope="col" colspan="2">ISO 639-1/ISO 639-2 + UN M.49 (Example macro regions)</th>
1832      </tr>
1833      </thead>
1834      <tbody>
1835      <tr>
1836          <td><dl><dt><code>es-PR</code></dt><dd>Spanish as used in <strong>Puerto Rico</strong></dd></dl></td>
1837          <td rowspan="3"><dl><dt><code>es-419</code></dt><dd>Spanish as used in <strong>Latin America &amp; the Caribbean</strong></dd></dl></td>
1838          <td rowspan="4"><dl><dt><code>es-019</code></dt><dd>Spanish as used in <strong>the Americas</strong></dd></dl></td>
1839      </tr>
1840      <tr>
1841          <td><dl><dt><code>es-HN</code></dt><dd>Spanish as used in <strong>Honduras</strong></dd></dl></td>
1842      </tr>
1843      <tr>
1844          <td><dl><dt><code>es-AR</code></dt><dd>Spanish as used in <strong>Argentina</strong></dd></dl></td>
1845      </tr>
1846      <tr>
1847          <td><dl><dt><code>es-US</code></dt><dd>Spanish as used in <strong>United States of America</strong></dd></dl></td>
1848          <td><dl><dt><code>es-021</code></dt><dd>Spanish as used in <strong>North America</strong></dd></dl></td>
1849      </tr>
1850      </tbody>
1851      </table>
1852  
1853      <p>Example of where the <a href="http://www.iso.ch/iso/en/prods-services/iso3166ma/02iso-3166-code-lists/list-en1.html">ISO 3166-1 alpha-2</a> is ambiguous and why <a href="http://unstats.un.org/unsd/methods/m49/m49.htm">UN M.49</a> might be preferred:</p>
1854  
1855      <table summary="Example where the ISO 3166-1 alpha-2 is ambiguous">
1856      <caption>Coding for ambiguous ISO 3166-1 alpha-2 regions</caption>
1857      <thead>
1858      <tr>
1859          <th scope="col" colspan="2"><code>CS</code> assignment pre-1994</th>
1860          <th scope="col" colspan="2"><code>CS</code> assignment post-1994</th>
1861      </tr>
1862      </thead>
1863      <tbody>
1864      <tr>
1865          <td colspan="2">
1866          <dl>
1867          <dt><code>CS</code></dt><dd><strong>Czechoslovakia</strong> (ISO 3166-1)</dd>
1868          <dt><code>200</code></dt><dd><strong>Czechoslovakia</strong> (UN M.49)</dd>
1869          </dl>
1870          </td>
1871          <td colspan="2">
1872          <dl>
1873          <dt><code>CS</code></dt><dd><strong>Serbian &amp; Montenegro</strong> (ISO 3166-1)</dd>
1874          <dt><code>891</code></dt><dd><strong>Serbian &amp; Montenegro</strong> (UN M.49)</dd>
1875          </dl>
1876          </td>
1877      </tr>
1878      <tr>
1879          <td>
1880          <dl>
1881          <dt><code>CZ</code></dt><dd><strong>Czech Republic</strong> (ISO 3166-1)</dd>
1882          <dt><code>203</code></dt><dd><strong>Czech Republic</strong> (UN M.49)</dd>
1883          </dl>
1884          </td>
1885          <td>
1886          <dl>
1887          <dt><code>SK</code></dt><dd><strong>Slovakia</strong> (ISO 3166-1)</dd>
1888          <dt><code>703</code></dt><dd><strong>Slovakia</strong> (UN M.49)</dd>
1889          </dl>
1890          </td>
1891          <td>
1892          <dl>
1893          <dt><code>RS</code></dt><dd><strong>Serbia</strong> (ISO 3166-1)</dd>
1894          <dt><code>688</code></dt><dd><strong>Serbia</strong> (UN M.49)</dd>
1895          </dl>
1896          </td>
1897          <td>
1898          <dl>
1899          <dt><code>ME</code></dt><dd><strong>Montenegro</strong> (ISO 3166-1)</dd>
1900          <dt><code>499</code></dt><dd><strong>Montenegro</strong> (UN M.49)</dd>
1901          </dl>
1902          </td>
1903      </tr>
1904      </tbody>
1905      </table>
1906  
1907      <h4>Macro-languages &amp; Topolects:</h4>
1908  
1909      <p><a href="http://tools.ietf.org/html/rfc4646">RFC 4646</a> anticipates features which shall be available in (currently draft) <a href="http://www.sil.org/iso639-3/">ISO 639-3</a> which aims to provide as complete enumeration of languages as possible, including living, extinct, ancient and constructed languages, whether majour, minor or unwritten. A new feature of <a href="http://www.sil.org/iso639-3/">ISO 639-3</a> compared to the previous two revisions is the concept of <a href="http://www.sil.org/iso639-3/macrolanguages.asp">macrolanguages</a> where Arabic and Chinese are two such examples. In such cases, their respective codes of <code>ar</code> and <code>zh</code> is very vague as to which dialect/topolect is used or perhaps some terse classical variant which may be difficult for all but very educated users. For such macrolanguages, it is recommended that the sub-language tag is used as a suffix to the macrolanguage tag, eg:</p>
1910  
1911      <table summary="Examples of macrolanguages used with sub-language subtags">
1912      <caption>Macrolanguage subtag + sub-language subtag examples</caption>
1913      <thead>
1914      <tr>
1915          <th scope="col">Language tag</th>
1916          <th scope="col">Description</th>
1917          <th scope="col">Component subtags</th>
1918      </tr>
1919      </thead>
1920      <tbody>
1921      <tr>
1922          <td><code>zh-cmn</code></td>
1923          <td>Mandarin (Putonghau/Guoyu) Chinese</td>
1924          <td><code>macrolanguage</code>+<code>sublanguage</code></td>
1925      </tr>
1926      <tr>
1927          <td><code>zh-yue</code></td>
1928          <td>Yue (Cantonese) Chinese</td>
1929          <td><code>macrolanguage</code>+<code>sublanguage</code></td>
1930      </tr>
1931      <tr>
1932          <td><code>zh-cmn-Hans</code></td>
1933          <td>Mandarin (Putonghau/Guoyu) Chinese written in Simplified script</td>
1934          <td><code>macrolanguage</code>+<code>sublanguage</code>+<code>script</code></td>
1935      </tr>
1936      <tr>
1937          <td><code>zh-cmn-Hant</code></td>
1938          <td>Mandarin (Putonghau/Guoyu) Chinese written in Traditional script</td>
1939          <td><code>macrolanguage</code>+<code>sublanguage</code>+<code>script</code></td>
1940      </tr>
1941      <tr>
1942          <td><code>zh-nan-Latn-TW</code></td>
1943          <td>Minnan (Hoklo) Chinese written in Latin script (POJ Romanisation) as used in Taiwan</td>
1944          <td><code>macrolanguage</code>+<code>sublanguage</code>+<code>script</code>+<code>region</code></td>
1945      </tr>
1946      </tbody>
1947      </table>
1948  
1949      <a name="otherconsiderations"></a><h3>6.ii. Other considerations</h3>
1950  
1951      <h4>Normalisation of language tags for phpBB:</h4>
1952  
1953      <p>For phpBB, the language tags are <strong>not</strong> used in their raw form and instead converted to all lower-case and have the hyphen <code>-</code> replaced with an underscore <code>_</code> where appropriate, with some examples below:</p>
1954  
1955      <table summary="Normalisation of language tags for usage in phpBB">
1956      <caption>Language tag normalisation examples</caption>
1957      <thead>
1958      <tr>
1959          <th scope="col">Raw language tag</th>
1960          <th scope="col">Description</th>
1961          <th scope="col">Value of <code>USER_LANG</code><br />in <code>./common.php</code></th>
1962          <th scope="col">Language pack directory<br />name in <code>/language/</code></th>
1963      </tr>
1964      </thead>
1965      <tbody>
1966      <tr>
1967          <td><code>en</code></td>
1968          <td>British English</td>
1969          <td><code>en</code></td>
1970          <td><code>en</code></td>
1971      </tr>
1972      <tr>
1973          <td><code>de-AT</code></td>
1974          <td>German as used in Austria</td>
1975          <td><code>de-at</code></td>
1976          <td><code>de_at</code></td>
1977      </tr>
1978      <tr>
1979          <td><code>es-419</code></td>
1980          <td>Spanish as used in Latin America &amp; Caribbean</td>
1981          <td><code>en-419</code></td>
1982          <td><code>en_419</code></td>
1983      </tr>
1984      <tr>
1985          <td><code>zh-yue-Hant-HK</code></td>
1986          <td>Cantonese written in Traditional script as used in Hong Kong</td>
1987          <td><code>zh-yue-hant-hk</code></td>
1988          <td><code>zh_yue_hant_hk</code></td>
1989      </tr>
1990      </tbody>
1991      </table>
1992  
1993      <h4>How to use <code>iso.txt</code>:</h4>
1994  
1995      <p>The <code>iso.txt</code> file is a small UTF-8 encoded plain-text file which consists of three lines:</p>
1996  
1997      <ol>
1998          <li><code>Language's English name</code></li>
1999          <li><code>Language's local name</code></li>
2000          <li><code>Authors information</code></li>
2001      </ol>
2002  
2003      <p><code>iso.txt</code> is automatically generated by the language pack submission system on phpBB.com. You don't have to create this file yourself if you plan on releasing your language pack on phpBB.com, but do keep in mind that phpBB itself does require this file to be present.</p>
2004  
2005      <p>Because language tags themselves are meant to be machine read, they can be rather obtuse to humans and why descriptive strings as provided by <code>iso.txt</code> are needed. Whilst <code>en-US</code> could be fairly easily deduced to be "English as used in the United States", <code>de-CH</code> is more difficult less one happens to know that <code>de</code> is from "<span lang="de">Deutsch</span>", German for "German" and <code>CH</code> is the abbreviation of the official Latin name for Switzerland, "<span lang="la">Confoederatio Helvetica</span>".</p>
2006  
2007      <p>For the English language description, the language name is always first and any additional attributes required to describe the subtags within the language code are then listed in order separated with commas and enclosed within parentheses, eg:</p>
2008  
2009      <table summary="English language description examples of iso.txt for usage in phpBB">
2010      <caption>English language description examples for iso.txt</caption>
2011      <thead>
2012      <tr>
2013          <th scope="col">Raw language tag</th>
2014          <th scope="col">English description within <code>iso.txt</code></th>
2015      </tr>
2016      </thead>
2017      <tbody>
2018      <tr>
2019          <td><code>en</code></td>
2020          <td>British English</td>
2021      </tr>
2022      <tr>
2023          <td><code>en-US</code></td>
2024          <td>English (United States)</td>
2025      </tr>
2026      <tr>
2027          <td><code>en-053</code></td>
2028          <td>English (Australia &amp; New Zealand)</td>
2029      </tr>
2030      <tr>
2031          <td><code>de</code></td>
2032          <td>German</td>
2033      </tr>
2034      <tr>
2035          <td><code>de-CH-1996</code></td>
2036          <td>German (Switzerland, 1996 orthography)</td>
2037      </tr>
2038      <tr>
2039          <td><code>gws-1996</code></td>
2040          <td>Swiss German (1996 orthography)</td>
2041      </tr>
2042      <tr>
2043          <td><code>zh-cmn-Hans-CN</code></td>
2044          <td>Mandarin Chinese (Simplified, Mainland China)</td>
2045      </tr>
2046      <tr>
2047          <td><code>zh-yue-Hant-HK</code></td>
2048          <td>Cantonese Chinese (Traditional, Hong Kong)</td>
2049      </tr>
2050      </tbody>
2051      </table>
2052  
2053      <p>For the localised language description, just translate the English version though use whatever appropriate punctuation typical for your own locale, assuming the language uses punctuation at all.</p>
2054  
2055      <h4>Unicode bi-directional considerations:</h4>
2056  
2057      <p>Because phpBB is now UTF-8, all translators must take into account that certain strings may be shown when the directionality of the document is either opposite to normal or is ambiguous.</p>
2058  
2059      <p>The various Unicode control characters for bi-directional text and their HTML enquivalents where appropriate are as follows:</p>
2060  
2061      <table summary="Table of the various Unicode bidirectional control characters">
2062      <caption>Unicode bidirectional control characters &amp; HTML elements/entities</caption>
2063      <thead>
2064      <tr>
2065          <th scope="col">Unicode character<br />abbreviation</th>
2066          <th scope="col">Unicode<br />code-point</th>
2067          <th scope="col">Unicode character<br />name</th>
2068          <th scope="col">Equivalent HTML<br />markup/entity</th>
2069          <th scope="col">Raw character<br />(enclosed between '')</th>
2070      </tr>
2071      </thead>
2072      <tbody>
2073      <tr>
2074          <td><code>LRM</code></td>
2075          <td><code>U+200E</code></td>
2076          <td>Left-to-Right Mark</td>
2077          <td><code>&amp;lrm;</code></td>
2078          <td>'&#x200E;'</td>
2079      </tr>
2080      <tr>
2081          <td><code>RLM</code></td>
2082          <td><code>U+200F</code></td>
2083          <td>Right-to-Left Mark</td>
2084          <td><code>&amp;rlm;</code></td>
2085          <td>'&#x200F;'</td>
2086      </tr>
2087      <tr>
2088          <td><code>LRE</code></td>
2089          <td><code>U+202A</code></td>
2090          <td>Left-to-Right Embedding</td>
2091          <td><code>dir=&quot;ltr&quot;</code></td>
2092          <td>'&#x202A;'</td>
2093      </tr>
2094      <tr>
2095          <td><code>RLE</code></td>
2096          <td><code>U+202B</code></td>
2097          <td>Right-to-Left Embedding</td>
2098          <td><code>dir=&quot;rtl&quot;</code></td>
2099          <td>'&#x202B;'</td>
2100      </tr>
2101      <tr>
2102          <td><code>PDF</code></td>
2103          <td><code>U+202C</code></td>
2104          <td>Pop Directional Formatting</td>
2105          <td><code>&lt;/bdo&gt;</code></td>
2106          <td>'&#x202C;'</td>
2107      </tr>
2108      <tr>
2109          <td><code>LRO</code></td>
2110          <td><code>U+202D</code></td>
2111          <td>Left-to-Right Override</td>
2112          <td><code>&lt;bdo dir=&quot;ltr&quot;&gt;</code></td>
2113          <td>'&#x202D;'</td>
2114      </tr>
2115      <tr>
2116          <td><code>RLO</code></td>
2117          <td><code>U+202E</code></td>
2118          <td>Right-to-Left Override</td>
2119          <td><code>&lt;bdo dir=&quot;rtl&quot;&gt;</code></td>
2120          <td>'&#x202E;'</td>
2121      </tr>
2122      </tbody>
2123      </table>
2124  
2125      <p>For <code>iso.txt</code>, the directionality of the text can be explicitly set using special Unicode characters via any of the three methods provided by left-to-right/right-to-left markers/embeds/overrides, as without them, the ordering of characters will be incorrect, eg:</p>
2126  
2127      <table summary="Effect of using Unicode bidirectional control characters within iso.txt">
2128      <caption>Unicode bidirectional control characters iso.txt</caption>
2129      <thead>
2130      <tr>
2131          <th scope="col">Directionality</th>
2132          <th scope="col">Raw character view</th>
2133          <th scope="col">Display of localised<br />description in <code>iso.txt</code></th>
2134          <th scope="col">Ordering</th>
2135      </tr>
2136      </thead>
2137      <tbody>
2138      <tr>
2139          <td><code>dir=&quot;ltr&quot;</code></td>
2140          <td>English (Australia &amp; New Zealand)</td>
2141          <td dir="ltr">English (Australia &amp; New Zealand)</td>
2142          <td class="good">Correct</td>
2143      </tr>
2144      <tr>
2145          <td><code>dir=&quot;rtl&quot;</code></td>
2146          <td>English (Australia &amp; New Zealand)</td>
2147          <td dir="rtl">English (Australia &amp; New Zealand)</td>
2148          <td class="bad">Incorrect</td>
2149      </tr>
2150      <tr>
2151          <td><code>dir=&quot;rtl&quot;</code> with <code>LRM</code></td>
2152          <td>English (Australia &amp; New Zealand)<code>U+200E</code></td>
2153          <td dir="rtl">English (Australia &amp; New Zealand)&#x200E;</td>
2154          <td class="good">Correct</td>
2155      </tr>
2156      <tr>
2157          <td><code>dir=&quot;rtl&quot;</code> with <code>LRE</code> &amp; <code>PDF</code></td>
2158          <td><code>U+202A</code>English (Australia &amp; New Zealand)<code>U+202C</code></td>
2159          <td dir="rtl">&#x202A;English (Australia &amp; New Zealand)&#x202C;</td>
2160          <td class="good">Correct</td>
2161      </tr>
2162      <tr>
2163          <td><code>dir=&quot;rtl&quot;</code> with <code>LRO</code> &amp; <code>PDF</code></td>
2164          <td><code>U+202D</code>English (Australia &amp; New Zealand)<code>U+202C</code></td>
2165          <td dir="rtl">&#x202D;English (Australia &amp; New Zealand)&#x202C;</td>
2166          <td class="good">Correct</td>
2167      </tr>
2168      </tbody>
2169      </table>
2170  
2171      <p>In choosing which of the three methods to use, in the majority of cases, the <code>LRM</code> or <code>RLM</code> to put a &quot;strong&quot; character to fully enclose an ambiguous punctuation character and thus make it inherit the correct directionality is sufficient.</p>
2172      <p>Within some cases, there may be mixed scripts of a left-to-right and right-to-left direction, so using <code>LRE</code> &amp; <code>RLE</code> with <code>PDF</code> may be more appropriate. Lastly, in very rare instances where directionality must be forced, then use <code>LRO</code> &amp; <code>RLO</code> with <code>PDF</code>.</p>
2173      <p>For further information on authoring techniques of bi-directional text, please see the W3C tutorial on <a href="http://www.w3.org/International/tutorials/bidi-xhtml/">authoring techniques for XHTML pages with bi-directional text</a>.</p>
2174  
2175      <h4>Working with placeholders:</h4>
2176  
2177      <p>As phpBB is translated into languages with different ordering rules to that of English, it is possible to show specific values in any order deemed appropriate. Take for example the extremely simple &quot;Page <em>X</em> of <em>Y</em>&quot;, whilst in English this could just be coded as:</p>
2178  
2179      <div class="codebox"><pre>
2180      ...
2181  'PAGE_OF'    =&gt;    'Page %s of %s',
2182          /* Just grabbing the replacements as they
2183          come and hope they are in the right order */
2184      ...
2185      </pre></div>
2186  
2187      <p>&hellip; a clearer way to show explicit replacement ordering is to do:</p>
2188  
2189      <div class="codebox"><pre>
2190      ...
2191  'PAGE_OF'    =&gt;    'Page %1$s of %2$s',
2192          /* Explicit ordering of the replacements,
2193          even if they are the same order as English */
2194      ...
2195      </pre></div>
2196  
2197      <p>Why bother at all? Because some languages, the string transliterated back to English might read something like:</p>
2198  
2199      <div class="codebox"><pre>
2200      ...
2201  'PAGE_OF'    =&gt;    'Total of %2$s pages, currently on page %1$s',
2202          /* Explicit ordering of the replacements,
2203          reversed compared to English as the total comes first */
2204      ...
2205      </pre></div>
2206  
2207      <a name="writingstyle"></a><h3>6.iii. Writing Style</h3>
2208  
2209      <h4>Miscellaneous tips &amp; hints:</h4>
2210  
2211      <p>As the language files are PHP files, where the various strings for phpBB are stored within an array which in turn are used for display within an HTML page, rules of syntax for both must be considered. Potentially problematic characters are: <code>'</code> (straight quote/apostrophe), <code>&quot;</code> (straight double quote), <code>&lt;</code> (less-than sign), <code>&gt;</code> (greater-than sign) and <code>&amp;</code> (ampersand).</p>
2212  
2213      <p class="bad">// Bad - The un-escapsed straight-quote/apostrophe will throw a PHP parse error</p>
2214  
2215      <div class="codebox"><pre>
2216      ...
2217  'CONV_ERROR_NO_AVATAR_PATH'
2218      =&gt;    'Note to developer: you must specify $convertor['avatar_path'] to use %s.',
2219      ...
2220      </pre></div>
2221  
2222      <p class="good">// Good - Literal straight quotes should be escaped with a backslash, ie: \</p>
2223  
2224      <div class="codebox"><pre>
2225      ...
2226  'CONV_ERROR_NO_AVATAR_PATH'
2227      =&gt;    'Note to developer: you must specify $convertor[\'avatar_path\'] to use %s.',
2228      ...
2229      </pre></div>
2230  
2231      <p>However, because phpBB3 now uses UTF-8 as its sole encoding, we can actually use this to our advantage and not have to remember to escape a straight quote when we don't have to:</p>
2232  
2233      <p class="bad">// Bad - The un-escapsed straight-quote/apostrophe will throw a PHP parse error</p>
2234  
2235      <div class="codebox"><pre>
2236      ...
2237  'USE_PERMISSIONS'    =&gt;    'Test out user's permissions',
2238      ...
2239      </pre></div>
2240  
2241      <p class="good">// Okay - However, non-programmers wouldn't type "user\'s" automatically</p>
2242  
2243      <div class="codebox"><pre>
2244      ...
2245  'USE_PERMISSIONS'    =&gt;    'Test out user\'s permissions',
2246      ...
2247      </pre></div>
2248  
2249      <p class="good">// Best - Use the Unicode Right-Single-Quotation-Mark character</p>
2250  
2251      <div class="codebox"><pre>
2252      ...
2253  'USE_PERMISSIONS'    =&gt;    'Test out user&rsquo;s permissions',
2254      ...
2255      </pre></div>
2256  
2257      <p>The <code>&quot;</code> (straight double quote), <code>&lt;</code> (less-than sign) and <code>&gt;</code> (greater-than sign) characters can all be used as displayed glyphs or as part of HTML markup, for example:</p>
2258  
2259      <p class="bad">// Bad - Invalid HTML, as segments not part of elements are not entitised</p>
2260  
2261      <div class="codebox"><pre>
2262      ...
2263  'FOO_BAR'    =&gt;    'PHP version &lt; 4.3.3.&lt;br /&gt;
2264      Visit &quot;Downloads&quot; at &lt;a href=&quot;http://www.php.net/&quot;&gt;www.php.net&lt;/a&gt;.',
2265      ...
2266      </pre></div>
2267  
2268      <p class="good">// Okay - No more invalid HTML, but &quot;&amp;quot;&quot; is rather clumsy</p>
2269  
2270      <div class="codebox"><pre>
2271      ...
2272  'FOO_BAR'    =&gt;    'PHP version &amp;lt; 4.3.3.&lt;br /&gt;
2273      Visit &amp;quot;Downloads&amp;quot; at &lt;a href=&quot;http://www.php.net/&quot;&gt;www.php.net&lt;/a&gt;.',
2274      ...
2275      </pre></div>
2276  
2277      <p class="good">// Best - No more invalid HTML, and usage of correct typographical quotation marks</p>
2278  
2279      <div class="codebox"><pre>
2280      ...
2281  'FOO_BAR'    =&gt;    'PHP version &amp;lt; 4.3.3.&lt;br /&gt;
2282      Visit &ldquo;Downloads&rdquo; at &lt;a href=&quot;http://www.php.net/&quot;&gt;www.php.net&lt;/a&gt;.',
2283      ...
2284      </pre></div>
2285  
2286      <p>Lastly, the <code>&amp;</code> (ampersand) must always be entitised regardless of where it is used:</p>
2287  
2288      <p class="bad">// Bad - Invalid HTML, none of the ampersands are entitised</p>
2289  
2290      <div class="codebox"><pre>
2291      ...
2292  'FOO_BAR'    =&gt;    '&lt;a href=&quot;http://somedomain.tld/?foo=1&amp;bar=2&quot;&gt;Foo &amp; Bar&lt;/a&gt;.',
2293      ...
2294      </pre></div>
2295  
2296      <p class="good">// Good - Valid HTML, amperands are correctly entitised in all cases</p>
2297  
2298      <div class="codebox"><pre>
2299      ...
2300  'FOO_BAR'    =&gt;    '&lt;a href=&quot;http://somedomain.tld/?foo=1&amp;amp;bar=2&quot;&gt;Foo &amp;amp; Bar&lt;/a&gt;.',
2301      ...
2302      </pre></div>
2303  
2304      <p>As for how these charcters are entered depends very much on choice of Operating System, current language locale/keyboard configuration and native abilities of the text editor used to edit phpBB language files. Please see <a href="http://en.wikipedia.org/wiki/Unicode#Input_methods">http://en.wikipedia.org/wiki/Unicode#Input_methods</a> for more information.</p>
2305  
2306      <h4>Spelling, punctuation, grammar, et cetera:</h4>
2307  
2308      <p>The default language pack bundled with phpBB is <strong>British English</strong> using <a href="http://www.cambridge.org/">Cambridge University Press</a> spelling and is assigned the language code <code>en</code>. The style and tone of writing tends towards formal and translations <strong>should</strong> emulate this style, at least for the variant using the most compact language code. Less formal translations or those with colloquialisms <strong>must</strong> be denoted as such via either an <code>extension</code> or <code>privateuse</code> tag within its language code.</p>
2309  
2310          </div>
2311  
2312          <div class="back2top"><a href="#wrap" class="top">Back to Top</a></div>
2313  
2314          <span class="corners-bottom"><span></span></span></div>
2315      </div>
2316  
2317      <hr />
2318  
2319  <a name="disclaimer"></a><h2>7. Copyright and disclaimer</h2>
2320  
2321      <div class="paragraph">
2322          <div class="inner"><span class="corners-top"><span></span></span>
2323  
2324          <div class="content">
2325  
2326      <p>This application is opensource software released under the <a href="http://opensource.org/licenses/gpl-2.0.php">GNU General Public License v2</a>. Please see source code and the docs directory for more details. This package and its contents are Copyright (c) <a href="https://www.phpbb.com/">phpBB Group</a>, All Rights Reserved.</p>
2327  
2328          </div>
2329  
2330          <div class="back2top"><a href="#wrap" class="top">Back to Top</a></div>
2331  
2332          <span class="corners-bottom"><span></span></span></div>
2333      </div>
2334  
2335  <!-- END DOCUMENT -->
2336  
2337      <div id="page-footer">
2338          <div class="version">&nbsp;</div>
2339      </div>
2340  </div></div>
2341  
2342  <div>
2343      <a id="bottom" name="bottom" accesskey="z"></a>
2344  </div>
2345  
2346  </body>
2347  </html>


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