related posts - pulling tags from a specific post type

Question

I'm currently using the following bit of code to display related posts on my single template.

    <?php
        $orig_post = $post;
        global $post;
        $tags = wp_get_post_tags($post->ID);

        if ($tags) {
            $tag_ids = array();
            foreach($tags as $individual_tag) $tag_ids[] = $individual_tag->term_id;
            $args=array(
                'tag__in' => $tag_ids,
                'post__not_in' => array($post->ID),
                'posts_per_page'=>5, // Number of related videos that will be shown.
                'caller_get_posts'=>1
            );

            $my_query = new wp_query( $args );
            if( $my_query->have_posts() ) {
                echo '<section id="related-videos"><h3><span>Related Videos</span></h3><ul>';

                while( $my_query->have_posts() ) {
                $my_query->the_post(); ?>

                <li>
                    <a class="related-thumb" href="<? the_permalink()?>" rel="bookmark" title="<?php the_title(); ?>"><?php the_post_thumbnail('related-thumb'); ?></a>
                    <section class="related-content">
                        <a href="<? the_permalink()?>" rel="bookmark" title="<?php the_title(); ?>"><?php the_title(); ?></a>
                    </section>
                </li>

                <? }

                echo '</ul></section>';
            }
        }

        $post = $orig_post;
        wp_reset_query();

I'm wondering if there is a way I can pull tags from only a certain post type. Maybe adding something like 'post_type=videos' somewhere? Not sure where, though. Can someone help me out? Thank you.

Answer 1

Something exactly like 'post_type' => 'videos' somewhere in your $args array :)

Answer 2

I am not sure from your description - do you want to only display this for posts of specific type or only display posts of specific type as related ones?

Your guess is precise, query does take post_type argument, see Type & Status Parameters in Codex.

Answer 3

I couldn't find a way to filter via post type when retrieving a list of tags. I would do something like this:

function get_tags_per_post_type() {
    $post_list = get_posts(array('post_type' => ''));
    $tag_list = array();
    foreach($post_list as $current_post) {
        $current_tag_list = wp_get_post_tags($current_post->ID);
        foreach ($current_tag_list as $tag) {
            $tag_list[] = $tag->term_id;
        }
    }

    $tag_list = array_unique($tag_list);
    return $tag_list;
}

This retrieves a list of tag term ids related to a particular post type. If you want a list of tag objects, then we would need to create a function which identify duplicate tag object being added to $tag_list.

HTH