<?php
/*
Plugin Name: Topic Icon
Version: 0.2
Plugin URI: http://www.trommetter.com/log/archives/topic-icon.txt
Author: Jason A. Trommetter
Email: jason@trommetter.org

Note: Requires WordPress 1.2 or higher.
*/
function topic_icon ($text) 
{
    $topic_uri = "/icon/directory/";
    $topic_dir = "/home/you/icon/directory/";
    $align = "right";
    $prefix = "topic";
    $filetype = ".gif";
    
    $content = '';
    $values = get_post_custom_values('topicicon');
    if ($values[0] == 'none') {
        $image_name = '';
    } elseif ($values[0] != '') {
        $filename = $topic_dir . $values[0];
        $imagename = $topic_uri . $values[0];
    } else {
        /* Here we're going to try and automagically assign a topic
           icon to this post. */
        $categories = get_the_category();
        /* We pick the first category name that comes up in the list. */
        $category_name = $categories[0]->cat_name;
        $filename = $topic_dir . $prefix .
            strtolower($category_name) . $filetype;
        if (file_exists($filename))
        {
            $imagename = $topic_uri . $prefix .
                strtolower($category_name) . $filetype;
        } else {
	    $imagename = '';
	}
    }

    if (strlen($imagename) > 0) {
	@list($width, $height, $type, $attr) =
		getimagesize($filename);
        $content .= "<img src='" . $imagename . "'";
        $content .= " align='" . $align . "'";
	$content .= " width='" . $width . "'";
	$content .= " height='" . $height . "'";
	$content .= " alt='" . $category_name . "'";
        $content .= " />\n";
    } else {
        $content = "<!--no icon-->";
    }

    $text = $content . $text;
    
    return $text;
}

add_filter ('the_content', 'topic_icon');

?>