village-idiot.org -- Related Posts for b2evolution

Related Posts for b2evolution

Quite a few people have asked me how I'm achieving the "might be related to .." entries that are included with some of the posts on this site. First, I am now using WordPress, and there is a WP hack for it. Since a few of the people that have asked are using b2evolution, I decided to see if I could adapt the WP hack to work with b2evolution. With a little help I've managed to do it.

First things first though. In order to do this you must make a change to one table in your database. I've written this assuming you are going to use phpmyadmin to access MySQL.

SQL:

ALTER TABLE `evo_posts` ADD FULLTEXT `post_related` (
`post_title` ,
`post_content`
)

Notice in the above that the table that contains your posts is hardcoded as evo_posts. If you are using another prefix you obviously need to change that.
What that does is create a full text index on your post_content and post_title fields.

Now, the function.
The standard disclaimer applies here. This probably is not the prettiest way to accomplish this, however it does work.

<?php
function relatedposts($limit=5, $before='<li>', $after='</li>') {
global $DB, $Item, $tableposts ;
$file = get_bloginfo('blogurl');
$terms = str_replace('-', ' ', $Item->title);
$sql = "SELECT ID, post_title, "
         . "MATCH (post_title, post_content) "
         . "AGAINST ('$terms') AS score "
         . "FROM $tableposts WHERE "
         . "MATCH (post_title, post_content) "
         . "AGAINST ('$terms') "
         . "AND (post_status = 'published' && ID != '$Item->ID') ";
$sql .= "ORDER BY score DESC LIMIT $limit";
$results = $DB->get_results($sql);
if ($results) {
foreach ($results as $result) {
$lid = $result->ID;
$post_title = stripslashes($result->post_title);
$title = htmlspecialchars(stripslashes($result->post_title));
$permalink = url_add_param( $file, 'p='. $lid. '&c=1' );
echo $before
                .'<a href="'. $permalink .'" rel="bookmark" title="Related Link: ' . $post_title . '">'
                .$title.'</a>'.$after;
}
} else {
        echo $before.'Not a damn thing. Woops!'.$after;
    }
}
?>

By default is will display 5 posts it thinks are related, based on what it indexes in your database. Those 5 posts will be displayed in a list. Calling this function is simple. The default usage would be

<?php relatedposts() ?>

If you want to reduce the number of returned links or change the way it is displayed, you can use something like

<?php relatedposts(2, ' ', ', '); ?>

That example will return 2 related posts that are followed by commas.

On this site, it's used similar to this:

<?php relatedposts(1, ' ', ' '); ?>

That returns one related post and no formatting.

That's all there is. I should add that obviously this needs to be used within your post loop. And once again, so we're clear, this is a modification of an already existing WordPress hack. This code works with b2evolution.

Oh, and if you are wondering how to add the function, where to put it, etc.. what I recommend is taking advantage of the legacy hacks support that b2evolution left in -- Copy the function into a file, name the file hacks.php and upload it to your conf/ directory.

December 8th, 2004 · code and tech-talk · whoo · Comments (0)