Search highlighting is probably a better example of the plugin system's power.

git-svn-id: http://svn.automattic.com/wordpress/trunk@1082 1a063a9b-81f0-0310-95a4-ce76da25c4cd
2004-04-16 02:25:44 +00:00 · 2004-04-16 02:25:44 +00:00 · 086d059e15
parent 74c2872215
commit 086d059e15
1 changed files with 133 additions and 0 deletions
--- a/wp-content/plugins/google-hilite.php
+++ b/wp-content/plugins/google-hilite.php
@ -0,0 +1,133 @@
+<?php
+/*
+Plugin Name: Search Hilite
+Plugin URI: http://wordpress.org/#
+Description: When someone is referred from a search engine like Google, Yahoo, or WordPress' own, the terms they search for are highlighted with this plugin. Packaged by <a href="http://photomatt.net/">Matt</a>.
+Author: Ryan Boren
+Author URI: http://rboren.nu
+*/ 
+
+/* Highlighting code c/o Ryan Boren */
+function get_search_query_terms($engine = 'google') {
+    global $s, $s_array;
+	$referer = urldecode($_SERVER[HTTP_REFERER]);
+	$query_array = array();
+	switch ($engine) {
+	case 'google':
+		// Google query parsing code adapted from Dean Allen's
+		// Google Hilite 0.3. http://textism.com
+		$query_terms = preg_replace('/^.*q=([^&]+)&?.*$/i','$1', $referer);
+		$query_terms = preg_replace('/\'|"/', '', $query_terms);
+		$query_array = preg_split ("/[\s,\+\.]+/", $query_terms);
+		break;
+
+	case 'lycos':
+		$query_terms = preg_replace('/^.*query=([^&]+)&?.*$/i','$1', $referer);
+		$query_terms = preg_replace('/\'|"/', '', $query_terms);
+		$query_array = preg_split ("/[\s,\+\.]+/", $query_terms);
+		break;
+
+	case 'yahoo':
+		$query_terms = preg_replace('/^.*p=([^&]+)&?.*$/i','$1', $referer);
+		$query_terms = preg_replace('/\'|"/', '', $query_terms);
+		$query_array = preg_split ("/[\s,\+\.]+/", $query_terms);
+		break;
+
+    case 'wordpress':
+        // Check the search form vars if the search terms
+        // aren't in the referer.
+        if ( ! preg_match('/^.*s=/i', $referer)) {
+            if (isset($s_array)) {
+                $query_array = $s_array;
+            } else if (isset($s)) {
+                $query_array = array($s);
+            }
+
+            break;
+        }
+
+		$query_terms = preg_replace('/^.*s=([^&]+)&?.*$/i','$1', $referer);
+		$query_terms = preg_replace('/\'|"/', '', $query_terms);
+		$query_array = preg_split ("/[\s,\+\.]+/", $query_terms);
+        break;
+	}
+
+	return $query_array;
+}
+
+function is_referer_search_engine($engine = 'google') {
+	$siteurl = get_settings('siteurl');
+	$referer = urldecode($_SERVER['HTTP_REFERER']);
+    //echo "referer is: $referer<br />";
+	if ( ! $engine ) {
+		return 0;
+	}
+
+	switch ($engine) {
+	case 'google':
+		if (preg_match('/^http:\/\/w?w?w?\.?google.*/i', $referer)) {
+			return 1;
+		}
+		break;
+
+    case 'lycos':
+		if (preg_match('/^http:\/\/search\.lycos.*/i', $referer)) {
+			return 1;
+		}
+        break;
+
+    case 'yahoo':
+		if (preg_match('/^http:\/\/search\.yahoo.*/i', $referer)) {
+			return 1;
+		}
+        break;
+
+    case 'wordpress':
+        if (preg_match("#^$siteurl#i", $referer)) {
+            return 1;
+        }
+        break;
+	}
+
+	return 0;
+}
+
+function hilite($text) {
+	$search_engines = array('wordpress', 'google', 'lycos', 'yahoo');
+
+	foreach ($search_engines as $engine) {
+		if ( is_referer_search_engine($engine)) {
+			$query_terms = get_search_query_terms($engine);
+			foreach ($query_terms as $term) {
+				if (!empty($term) && $term != ' ') {
+					if (!preg_match('/<.+>/',$text)) {
+						$text = preg_replace('/(\b'.$term.'\b)/i','<span class="hilite">$1</span>',$text);
+					} else {
+						$text = preg_replace('/(?<=>)([^<]+)?(\b'.$term.'\b)/i','$1<span class="hilite">$2</span>',$text);
+					}
+				}
+			}
+			break;
+		}
+	}
+
+	return $text;
+}
+
+function hilite_head() {
+	echo "
+<style type='text/css'>
+.hilite {
+	color: #fff;
+	background-color: #f93;
+}
+</style>
+";
+}
+
+// Highlight text and comments:
+add_filter('the_content', 'hilite');
+add_filter('comment_text', 'hilite');
+add_action('wp_head', 'hilite_head');
+
+?>