Extension:BreadCrumbs2

<?php
/***
 * BreadCrumbs2.php
 * @version 0.9
 * @date September 6, 2007
 * @author Eric Hartwell (http://www.ehartwell.com/InfoDabble/BreadCrumbs2)
 * @license Creative Commons Attribution 3.0
 
This extension generates "breadcrumbs" in the web navigation sense ("Where am I?")
 
To activate the functionality of this extension include the following in your
LocalSettings.php file:
 require_once('$IP/extensions/BreadCrumbs2.php');
 
Offered to the community for any use whatsoever with no restrictions other
than that credit be given to Eric Hartwell, at least in the source code,
according to the Creative Commons Attribution 3.0 License.
***/
 
# Change these constants to customize your installation
define ("DELIM", '@');                             // Delimiter/marker for parameters and keywords
define ("CRUMBPAGE", 'MediaWiki:Breadcrumbs');     // Default is 'MediaWiki:Breadcrumbs'
 
# Standard sanity check
if ( !defined( 'MEDIAWIKI' ) ) {
   echo( "This is an extension to the MediaWiki package and cannot be run standalone.\n" );
   die( -1 );
}
 
# Credits for Special:Version
$wgExtensionCredits['other'][] = array(
        'name' => 'BreadCrumbs2',
        'version' => '0.9',
        'author' => 'Eric Hartwell',
        'url' => 'http://www.ehartwell.com/InfoDabble/BreadCrumbs2',
        'description' => 'Breadcrumb navigation (where am I)'
);
 
# Hook function modifies skin output after it has been generated
$wgHooks['SkinTemplateOutputPageBeforeExec'][] = 'buildBreadcrumbs';
 
# This is the main function. Identify the categories for the current page,
# then locate the first match in the navigation list.
function buildBreadcrumbs( $skin, $template ) {
 
    # Get the list of categories for the current page       
    preg_match_all( '`title="Category:(.*?)"`', $skin->getCategories(), $matches, PREG_PATTERN_ORDER );
    $categories = $matches[1];
 
    # Treat the namespace as a category too
    if ( $skin->mTitle->getNsText() )
        $categories[] = $skin->mTitle->getNsText();
 
    # Load and parse the breadcrumb template. If it's a redirected page, extract redirect info
    $crumbs = matchFirstCategory( CRUMBPAGE, $categories );
    $breadcrumb = trim( $crumbs[0] . ' ' . $skin->mTitle->getText() );
    if ( preg_match('/\(Redirected.*?\)/', $template->data['subtitle'], $match) )
        $breadcrumb .= ' ' . $match[0];
    # Set the page subtitle to the breadcrumb contents
    $template->set( 'subtitle', $breadcrumb  );
 
    # If the current page is a category page, add it to the list
    # We didn't add it before because we don't want Category > Category'
    $pagecat = strstr( $skin->mTitle->getPrefixedText(), 'Category:' );
    if ( $pagecat !== FALSE )
        $categories[] = substr( $pagecat, strlen('Category:') );
    # If it's not a category page, try for an exact match of the title (e.g. 'Main')
    else
        $categories[] = $skin->mTitle->getText();
 
    # Mark the corresponding tab of the sidebar as active
    $crumbs = matchFirstCategory( CRUMBPAGE, $categories );
    if ( !empty($crumbs[1]) ) {
        # See if there's a corresponding link in the sidebar and mark it as active.
        # This is especially useful for skins that display the sidebar as a tab bar. 
        if ( method_exists( $template, 'setActiveSidebarLink' ) ) {
            # The DynamicSkin extension can build the tabs (sidebar) dynamically,
            # and not necessarily from $template->data['sidebar'], so DynamicSkin 
            # and derived skins have a setActiveSidebarLink() function
            $template->setActiveSidebarLink( $crumbs[1] );
        } else {
            # Normal skins use the global sidebar data
	    foreach ($template->data['sidebar'] as $bar => $cont) {
                foreach ($cont as $key => $val) {
                    if ( $val['text'] == $crumbs[1] )
                    {
                        $template->data['sidebar'][$bar][$key]['active'] = true;
                        break;
                    }
                }
            }                
        }
     }
 
    # Finally, see if we should change the site logo
    # Don't go overboard with this... subtle is better.
    if ( ! empty($crumbs[2]))
    {
        global $wgLogo, $wgScriptPath;
        $wgLogo = $wgScriptPath . '/' . $crumbs[2];
    }
 
    return true;
}
 
# Look up the menu corresponding to the first matching category from the list
function matchFirstCategory( $menuname, $categories ) {
    # First load and parse the template page 
    $content = loadTemplate( $menuname );
 
    # Navigation list
    $breadcrumb = '';
    preg_match_all( "`<li>\s*?(.*?)\s*</li>`", $content, $matches, PREG_PATTERN_ORDER );
 
    # Look for the first matching category or a default string
    foreach ( $matches[1] as $nav ) {
        $pos = strpos( $nav, DELIM );                // End of category
        if ( $pos !== false ) {
            $cat = trim( substr($nav, 0, $pos) );
            $crumb = trim( substr($nav, $pos + 1) );
            // Is there a match for any of our page's categories? 
            if ( $cat == 'default' ) {
                $breadcrumb = $crumb;
            }
            else if ( in_array( $cat, $categories ) ) {
                $breadcrumb = $crumb;
                break;
            }
        }
    }
 
    return normalizeParameters( $breadcrumb, DELIM, 3 );
}
 
# Loads and preprocesses the template page 
function loadTemplate( $title ) {
    global $wgUser, $wgParser, $wgTitle;
 
    # Load the template article for this skin
    $article = new Article( Title::newFromText( $title ) );
    if ( $article ) {
        $template = $article->fetchContent(0,false,false);
        if ( $template ) {
            # Drop leading and trailing blanks and escape delimiter before parsing
            # Substitute a few skin-related variables before parsing
            $template = preg_replace('/(^\s+|\s+$)/m', '', $template );
            $template = str_replace( DELIM.DELIM.DELIM, "\x07", $template);
            $template = preg_replace('/'.DELIM.DELIM.'(.*?)'.DELIM.DELIM.'/e',
                                     'translate_variable( $1 )', $template );
 
            # Use the parser preprocessor to evaluate conditionals in the template
            # Copy the parser to make sure we don't trash the parser state too much
            $lparse = clone $wgParser;
            $template = $lparse->parse( $template, $wgTitle, ParserOptions::newFromUser($wgUser) );
            $template = str_replace( '&nbsp;', ' ', $template->getText() );
            return $template ;
        }
    }
    return '';
}
 
# Normalize a delimited parameter line: trim leading and trailing blanks,
# restore escaped delimiter characters, add null elements until all optional
# parameters are accounted for, and drop extra parameters
function normalizeParameters( $input, $delimiter, $count ) {
     # Split the parameters into an array
    $params = explode( $delimiter, $input );
    $output = array();
    for ( $i = 0 ; $i < $count ; $i++ ) {
        $output[] = str_replace("\x07", $delimiter, ($i < count($params)) ? trim($params[$i]) : '');
    }
    return $output ;
}
 
# Returns HTML text for the specified pseudo-variable
function translate_variable( $tag )
{
    global $wgParser, $wgUser;
 
    switch ( strtoupper($tag) ) {
 
    case 'USERGROUPS':             // @@USERGROUPS@@ pseudo-variable: Groups this user belongs to
        $wgParser->disableCache(); // Mark this content as uncacheable
        return( implode( ",", $wgUser->getGroups() ) );
 
    case 'USERID':                 // @@USERID@@ pseudo-variable: User Name, blank if anonymous
        $wgParser->disableCache(); // Mark this content as uncacheable
        # getName() returns IP for anonymous users, so check if logged in first
        return( $wgUser->isLoggedIn() ? $wgUser->getName() : '' );
 
    }
}
 
?>

 preg_match_all( '`title="Kategorie:(.*?)"`', $skin->getCategories(), $matches, PREG_PATTERN_ORDER );

$parser = new Parser();
$parserOptions = new ParserOptions();
$categoryTitle = ($wgLanguageCode == 'zh') ? 'Category' : $parser->preprocess(wfMsgReal('pagecategories', array(1), true, true, false), null, $parserOptions);
$redirectString = $parser->preprocess(wfMsgReal('redirectedfrom', array('.*'), true, true, false), null, $parserOptions);
# Turn redirectString into a regular expression (already replaced $1 with .*)
$redirectString = str_replace(array('(', ')'), array('\(', '\)'), $redirectString);

if ( preg_match('/'.$redirectString.'/', $template->data['subtitle'], $match) )

$currentBreadcrumb = $template->data['subtitle'];
if (strlen($currentBreadcrumb) > 0)
    $breadcrumb = $breadcrumb . ' ' . $currentBreadcrumb;