root/trunk/plugins/searchhl.php

<?php
Class searchhl extends MvBlog_plugin implements MvBlog_pluginiface {
    /* variables */
    public $name    = "SearchHighlight";
    public $author  = "Michiel van Baak";
    public $license = "GPL";
    public $website = "http://www.mvblog.org";
    public $description = "Plugin to highlight the words typed in at searchengine.";

    private $_mvblog;

    /* methods */
    public function __construct(&$mvblog) {
        $this->addHook("text_output", "highlightsearch");
        $this->addHook("css_output" , "searchhlCSS");
        $this->_mvblog =& $mvblog;
    }

    public function activate() {
        /* get data, do whatever is needed on plugin activation */
    }

    public function deactivate() {
    }

    public function highlightsearch($text) {
        if (array_key_exists("HTTP_REFERER", $_SERVER) && $_SERVER["HTTP_REFERER"]) {
            //this is for google only right now.
            //TODO: implement some searchengine abstraction
            preg_match("/[\?|&]q=(.*)[$|&]/", $_SERVER["HTTP_REFERER"], $matches);
            if (array_key_exists(1, $matches) && $matches[1]) {
                //some stuff in the post has to be left alone. replace them with markers so we can put them back later
                preg_match_all("/<a[^>](.*?)>/si", $text, $txtmatches);
                foreach ($txtmatches[0] as $txtmatchk=>$txtmatchv) {
                    $text = str_replace($txtmatchv, "##".$txtmatchk."##", $text);
                }
                $searchwords = explode("+", $matches[1]);
                foreach ($searchwords as $k=>$v) {
                    $text = str_replace($v, "<span class=\"searchhl_".$k."\">".$v."</span>", $text);
                }
                //put the skipped stuff back in the buffer
                foreach ($txtmatches[0] as $txtmatchk=>$txtmatchv) {
                    $text = str_replace("##".$txtmatchk."##", $txtmatchv, $text);
                }
            }
        }
        return $text;
    }

    public function searchhlCSS($data) {
        $output  = $data;
        $output .= "\t<style type=\"text/css\">\n";
        $output .= "\t\t.searchhl_0 { background-color: #fcc; }\n";
        $output .= "\t\t.searchhl_1 { background-color: #ff0; }\n";
        $output .= "\t\t.searchhl_2 { background-color: #f0f; }\n";
        $output .= "\t\t.searchhl_3 { background-color: #0ff; }\n";
        $output .= "\t\t.searchhl_4 { background-color:#FF9900; }\n";
        $output .= "\t\t.searchhl_5 { background-color:#99FF66; }\n";
        $output .= "\t\t.searchhl_6 { background-color:#99CCFF; }\n";
        $output .= "\t\t.searchhl_7 { background-color:#FF3333; }\n";
        $output .= "\t\t.searchhl_8 { background-color:#FF99FF; }\n";
        $output .= "\t\t.searchhl_9 { background-color:#FFFFCC; }\n";
        $output .= "\t</style>\n";
        return $output;
    }
}
?>