[Mediawiki-l] SEO extension

[Michael]

I didn't know if anybody else would be interested in this or possibly 
adding it into the MediaWiki source tree but figured I'd toss this out 
for people to use or not use as they may. It enhances the keyword and 
description meta tags of the wiki by first allowing you to set the 
number of link text keywords by setting $wgKeywordsX. You can set the 
default keywords and description with $wgKeywords and $wgDescription. If 
either the keywords or description aren't set otherwise then they'll get 
filled in with the link text (as keywords did before). If you also use 
the extension then users can edit the page's keywords and description 
when editing the wiki using the keywords and description tags.

This can be useful for more fine grained control over how search engines 
index your wiki pages.


Change to includes/OutputPage.php.

---
# This function takes the existing and broken links for the page
# and uses the first 10 of them for META keywords
function addMetaTags () {
        global $wgLinkCache, $wgOut;
        global $wgKeywordsX, $wgKeywords, $wgDescription;
        $good = array_keys ( $wgLinkCache->mGoodLinks ) ;
        $bad = array_keys ( $wgLinkCache->mBadLinks ) ;
        if ( ! ( $wgKeywords && $wgDescription ) ) {
                $a = array_merge ( $good , $bad ) ;
                $wgKeywordsX ? $wgKeywordsX : 10;
                $a = array_slice ( $a , 0 , $wgKeywordsX ) ; # keywords max
                $a = implode ( "," , $a ) ;
                $strip = array(
                        "/<.*?>/" => '',
                        "/[_]/" => ' '
                );
                $a = htmlspecialchars(preg_replace(array_keys($strip), 
array_values($strip),$a ));
        }
        $wgKeywords = $wgKeywords ? $wgKeywords : $a;
        $wgOut->addMeta ( "keywords" , $wgKeywords );
        $wgDescription = $wgDescription ? $wgDescription : $a;
        $wgOut->addMeta ( "description" , $wgDescription );
}
---

New file, extensions/SEO.php.
---
/*
   MediaWiki extension to allow wiki users to change the page's keyword
   and description meta tags. Introduces the description and keywords tags.
*/

$wgExtensionFunctions[] = "SEO_DescriptionExtension";
$wgExtensionFunctions[] = "SEO_KeywordsExtension";

function SEO_DescriptionExtension () {
        global $wgParser;
        $wgParser->setHook( 'description', '_SEO_Description' );
}

function _SEO_Description ( $input ) {
        global $wgDescription;
        $wgDescription = $input;
        return '';
}

function SEO_KeywordsExtension () {
        global $wgParser;
        $wgParser->setHook( 'keywords', '_SEO_Keywords' );
}

function _SEO_Keywords ( $input ) {
        global $wgKeywords;
        $wgKeywords = $input;
        return '';
}
---

-- 
Michael <mogmios at mlug.missouri.edu>
http://kavlon.org