User:Ilmari Karonen/FancyTooltips

This is a proof-of-concept extension for a JS-less fix to bug 26587. You probably don't want to use it yet — the tooltips in this version just show the raw wikitext and generally look ugly. Give me a few more minutes to improve it... ;)

<?php
 
if ( !defined( 'MEDIAWIKI' ) ) {
        die( 'This file is a MediaWiki extension, it is not a valid entry point' );
}
 
// Credits:
$wgExtensionCredits['other'][] = array(
       'name'           => 'FancyTooltips',
       'version'        => '0.1',
       'author'         => 'Ilmari Karonen', 
       'url'            => 'http://www.mediawiki.org/wiki/User:Ilmari_Karonen/FancyTooltips', 
       'description'    => 'Replaces link tooltips with extracts of page text',
);
 
// Config variables:
$wgFancyTooltipsMaxLength = 100;
 
// Hooks:
$wgHooks['LinkBegin'][] = 'fancyTooltipsLinkBegin';
 
function fancyTooltipsLinkBegin ( $skin, $target, &$text, &$attribs, &$query, &$options, &$ret ) {
        global $wgFancyTooltipsMaxLength;
        static $ellipsis;
        static $cache = array();
 
        if ( array_key_exists( 'title', $attribs ) ) {
                return true;  // don't override explicit titles
        }
 
        // first check the cache
        $key = $target->getPrefixedDBkey();
        if ( array_key_exists( $key, $cache ) ) {
                $title = $cache[$key];
                if ( $title !== false ) {
                        $attribs['title'] = $title;
                }
                return true;
        }
 
        $rev = Revision::newFromTitle( $target );
        if ( !$rev ) {
                // redlink? special? whatever it is, ignore it
                $cache[$key] = false;  // cache negative result
                return true;
        }
 
        // TODO: This is a test implementation.  For the final
        // implementation we should fetch the parsed page and extract
        // the text from it.
 
        $content = $rev->getText();
        if ( $content ) {
                $title = mb_substr( $content, 0, $wgFancyTooltipsMaxLength );
                if ( strlen( $title ) < strlen( $content ) ) {
                        if ( !isset( $ellipsis ) ) {
                                $ellipsis = wfMsgForContent( 'ellipsis' );
                        }
                        $title .= $ellipsis;
                }
                $cache[$key] = $attribs['title'] = $title; 
        }
        else {
                $cache[$key] = false;  // cache negative result
        }
        return true;
}