Extension:TagAsCategory

<?php /**

* TagAsCategory
*
* A folksonomy extension for MediaWiki
*
* Copyright (c) 2007, Molecular
* BSD License
*
* Redistribution and use in source and binary forms, with or without modification, are
* permitted provided that the following conditions are met:
*
* 	* Redistributions of source code must retain the above copyright notice, this list of
* 	  conditions and the following disclaimer.
*
* 	* Redistributions in binary form must reproduce the above copyright notice, this list
* 	  of conditions and the following disclaimer in the documentation and/or other materials
* 	  provided with the distribution.
*
* 	* Neither the name of Molecular the names of its contributors may be used
* 	  to endorse or promote products derived from this software without specific prior
* 	  written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS
* OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY
* AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDERS
* AND CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
* SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
* OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*
* @version 1
* @copyright 2007 Molecular
* @author Glenn Barnett
* @author Paul Irish
* @link http://www.molecular.com/ Molecular
* @license http://www.opensource.org/licenses/bsd-license.php BSD License
*
*
* To activate this functionality, place this file in your extensions/ 
* subdirectory, and add the following line to LocalSettings.php:
*     require_once("$IP/extensions/TagAsCategory/TagAsCategory.php");
*
* We also recommend changing the "Categories" label to "Tags".  This can be 
* done by going to the "Special:Allmessages" page, and changing the
* value of "pagecategories" from "Category" to 
* "Tags" .
*/

if(! defined( 'MEDIAWIKI' ) ) {

  echo( "This is an extension to the MediaWiki package and cannot be run standalone.\n" );
  die( -1 );

} else {

   $wgExtensionCredits['other'][] = array(
       'name' => 'TagAsCategory',
       'author' =>'Molecular', 
       'url' => 'http://www.molecular.com',
       'description' => 'This Extension provides "folksonomy"-type tagging to articles, using Categories as the underlying functionality'
   );

   $wgHooks['ArticleViewHeader'][] = 'articleShowTagForm';
   $wgHooks['UnknownAction'][] = 'tagAction';

function articleShowTagForm(&$article) {

   global $wgOut;
   global $wgScript;   
   global $wgMessageCache;

   # add localized messages for the "Add Tag" and "(none)" interface strings
   $wgMessageCache->addMessages(
       array (
           'addtag' => 'Add Tag',
           'notags' => '(none)'
       )
   ); 

   # load the localized messages into string variables
   $sAddTag = wfMsg('addtag');
   $sNoTags = wfMsg('notags');
   $sTags = wfMsg('pagecategories');               # defined by default as "Category"
   $sCategoriesLink = wfMsg('pagecategorieslink'); # defined by default as "Special:Categories"

   # determine the URL for the form action
   $actionUrl = htmlspecialchars( $wgScript );        

   # generate the form HTML 
   $tagFormHTML=<<<ENDFORM
       <form action="{$actionUrl}" method="get" id="tagform" style="display: none;">
           <input type="hidden" name="title" value="{$article->mTitle->getPrefixedDBkey()}">
           <input type="hidden" name="action" value="tag">
           <input type="text" name="tag" value="" size="15" />    
           <input type="submit" value="{$sAddTag}" />
       </form>
       <script type="text/javascript">

       function moveTaggerBox(){

           if (document.getElementById('catlinks')){
               // if the Article is already in one or more categories, 
               // 'catlinks' will exist
               document.getElementById('catlinks').appendChild(document.getElementById('tagform'));
           }
           else 
           {
               // if 'catlinks' doesn't exist (the article is in 0 categories)
               // we must recreate the HTML 
               var div1=document.createElement('div');
               div1.setAttribute('id','catlinks');
               var p1=document.createElement('p');
               div1.appendChild(p1);
               var a1=document.createElement('a');
               a1.setAttribute('href',escape('{$sCategoriesLink}'));
               a1.setAttribute('title','{$sCategoriesLink}');
               p1.appendChild(a1);
               var txt1=document.createTextNode('{$sTags}');
               a1.appendChild(txt1);
               var txt2=document.createTextNode(': {$sNoTags}');
               p1.appendChild(txt2);

               document.getElementById('bodyContent').appendChild(div1);
               div1.appendChild(document.getElementById('tagform'));
               }

           document.getElementById('tagform').style.display = ; // we defined it as hidden. show it once it's placed correctly
       }

       hookEvent("load", moveTaggerBox); // hookEvent() defined in wikibits.js

       </script>

ENDFORM;

   $wgOut->addHTML($tagFormHTML);
   return true;

}

   function tagAction($action, $article) {

       global $wgUser; 
       global $wgRequest; 

       if($action == 'tag' && $wgUser->isAllowed('edit'))
       {
           # set wgUser??
           $content = $article->getContent();

           $newCategoryString = "[[Category:" . $wgRequest->getVal('tag') . "]]";

           // if $content doesn't already contain the new Category string...
           if (strpos($content, '$newCategoryString') == false) {

               // edit the content, appending the new Category string
               // (with newlines) at the bottom of the article.
               //
               // additionally, flag the edit as an 'update', and suppress
               // its inclusion in Recent Changes

               $article->doEdit(
                   $content . "\n" . $newCategoryString . "\n",
                   "Added tag: '" . $wgRequest->getVal('tag') . "'",
                   EDIT_UPDATE | EDIT_SUPPRESS_RC
               );

           }

           // view the article, and abort further processing by mediawiki (false)
           $article->view();
           return false;
       }
       else
       {
           // we don't have edit rights -- abort the operation, restoring
           // control to the default mediawiki behavior (true)
           return true;
       }
   }

}

?>