Changing Related Post Selection From Tags to Categories

[JeffCampagna]

Hey Everyone.

I am hoping this is the right place to ask this question.

I am using a new WordPress theme and it has native related post coding in it. The problem is the code uses Post Tags as the selection value instead of Post Category. I was wondering if anyone could help me with this strip of code. I want to change it so the theme gets Posts in the same Category, instead of Posts with the same Tags.

* Display related posts.

*

* @return void

*/

function stag_related_posts() {

    global $post;

    if( stag_rcp_user_has_no_access() )

        return;

    if( ! stag_theme_mod( 'post_settings', 'show_related_posts' ) )

        return;

    $tags = wp_get_post_tags( $post->ID );

    if ( count( $tags ) ) {

        $tags_ids = array();

        foreach($tags as $individual_tag) {

            $tag_ids[] = $individual_tag->term_id;

        }

        $query = new WP_Query( array(

            'tag__in' => $tags_ids,

            'post__not_in' => array( $post->ID ),

            'posts_per_page' => absint( stag_theme_mod( 'post_settings', 'related_posts_count' ) ),

            'caller_get_posts' => 1

        ) );

        // Add filter to attach 'post-grid' class

        add_filter( 'stag_showing_related_posts', '__return_true' );

        if( $query->have_posts() ) :

            echo '<section class="related-posts" data-layout="2-2-2-2">';

            while( $query->have_posts() ) : $query->the_post();

                get_template_part( 'content', get_post_format() );

            endwhile;

            echo '</section>';

        endif;

    }

    wp_reset_query();

    remove_all_filters( 'stag_showing_related_posts' );

}

I've tried simply replaces the words Tags with Categories, but it doesn't seem to do much.

Any help would be greatly, greatly, appreciated.