Max says…

thoughts of a web developer

Aug 21, 2007

A First Wordpress Plugin

As you can see from my previous post, my first attempt at writing a Wordpress Plugin was a success. This plugin is very simple and allows the user to embed a YouTube video into their post. The main function calls a callback function that replaces every occurrence of the tag ["youtube" video_id] (minus quotes) with a flash video corresponding to the video_id parameter.

Just paste the code below into a file called ‘youtube.php’ in your wp-content/plugins directory. You should then be able to activate it via the Plugins admin option. Once activated, you can place a YouTube video in your post by going to code-view and inserting ["youtube" video_id] (minus the quotes). The video_id parameter is the ‘v’ parameter in a YouTube URL. In the example below, the URL is http://www.youtube.com/watch?v=lL4L4Uv5rf0. Therefore, the video_id parameter should be lL4L4Uv5rf0. In the code below, you will need to remove the quotes around the word “youtube” in the regex on line 5, I had to put these in to display the code without it interpreting the tag… it’s a work in progress!

Code (php)
 
 
define("YOUTUBE_WIDTH", 425);
define("YOUTUBE_HEIGHT", 350);
define("YOUTUBE_TAG", "/["youtube" ([[:print:]]+)]/");
define("YOUTUBE_LINK", "<object type="\" data="\" height="\" width="\">
<param name="\" value="\"></param></object>");
 
function youtube_plugin_cb($match)
{
$html = YOUTUBE_LINK;
$html = str_replace("###YOUTUBE_ID###", $match[1], $html);
return ($html);
}
 
function youtube_plugin($content)
{
return (preg_replace_callback(YOUTUBE_TAG, ‘youtube_plugin_cb’, $content));
}
 
add_filter(‘the_content’, ‘youtube_plugin’);
add_filter(‘comment_text’, ‘youtube_plugin’);
 
?>