CODEWITHSUNDEEP
phpwordpresstaxonomy
Andre Bulatov
Andre Bulatov

Reputation: 1139

WordPress: tax query of X number of posts related by tag first, then by category if not enough in tag-related

Question

How to output tag related posts first, then IF there are less than 4 tag related posts, fill the rest of the 4 spots with category related posts?

Scenario

Sometimes a post has very few tags, or the tags it is labeled with have very fews posts. When outputting "related posts by tag," the area is either very sparse with 1 or 2 posts, or outright empty.

To solve this it would be good to show posts from related categories, if there are not enough tag related posts to satisfy posts_per_page => X.

So, something like this:

Scenario A -- if more than 4 tag-related posts exist, then:

Related Posts:

Show the below posts:

1. tag-related post #1
2. tag-related post #2
3. tag-related post #3
4. tag-related post #4

Do Not show the below posts:

5. tag-related post #5
6. tag-related post #6
7. tag-related post #7
...

Scenario B -- if only 2 tag-related posts exist, then:

Related Posts:

Show the below posts:

1. tag-related post #1
2. tag-related post #2  
3. category-related post #1
4. category-related post #2

Do Not show the below posts:

5. category-related post #3
6. category-related post #4
7. category-related post #5
...

What I've tried

The tax query I am using:

// start of the tax_query arguments
$args = array( 'posts_per_page'=>4, 'post__not_in' => array($post->ID), 'tax_query' => array( 'relation' => 'OR' ) );

// get current post tags
$tags = wp_get_object_terms( $post->ID, 'post_tag', array( 'fields' => 'ids' ) );

if ( !empty( $tags ) ) {
    $args['tax_query'][] = array(
        'taxonomy' => 'post_tag',
        'field'    => 'id',
        'terms'    => $tags
    );
}

// get current post categories
$categories = wp_get_object_terms( $post->ID, 'category', array( 'fields' => 'ids' ) );

if ( !empty( $categories ) ) {
    $args['tax_query'][] = array(
        'taxonomy' => 'category',
        'field'    => 'id',
        'terms'    => $categories
    );
}

// the query
$related_query = new WP_Query( $args );

As I understand it, that tax query says "get posts that are in the same categories, then get posts that are in the same tags, then output posts until 4 are on screen."

Yet it keeps outputting category posts first (of which there are many) which satisfies the 4 posts on screens rule and leaves out the most important tag-related posts. I've tried moving the code around, using AND instead of OR, which didn't work and made no sense to me anyways.

I've also seen these posts: WordPress - producing a list of posts filtered by tag and then category and Wordpress query posts by tag and category, but they are about outputting a list of posts that are filtered by tag AND category. I need posts first related by tag, and if 4 or more, then just output those top 4. If less than 4, then output up to as many category-related posts to meet the 4 posts criteria.

Clearly I am misunderstanding the query and/or the problem, so any help would be appreciated.

Upvotes: 0

Views: 2000

Answers (1)

Andre Bulatov
Andre Bulatov

Reputation: 1139

I finally got it all working. The following function will show up to 4 related posts, first going by tag, then category, then custom post type, then any post if none of the first 3 criteria match any posts.

function get_max_related_posts( $recent_posts = array(), $taxonomy_1 = 'post_tag', $taxonomy_2 = 'category', $total_posts = 4 ) {
    // First, make sure we are on a single page, if not, bail
    if ( !is_single() )
        return false;

    // Sanitize and vaidate our incoming data
    if ( 'post_tag' !== $taxonomy_1 ) {
        $taxonomy_1 = filter_var( $taxonomy_1, FILTER_SANITIZE_STRING );
        if ( !taxonomy_exists( $taxonomy_1 ) )
            return false;
    }

    if ( 'category' !== $taxonomy_2 ) {
        $taxonomy_2 = filter_var( $taxonomy_2, FILTER_SANITIZE_STRING );
        if ( !taxonomy_exists( $taxonomy_2 ) )
            return false;
    }

    if ( 4 !== $total_posts ) {
        $total_posts = filter_var( $total_posts, FILTER_VALIDATE_INT );
            if ( !$total_posts )
                return false;
    }

    // Everything checks out and is sanitized, lets get the current post
    $current_post = sanitize_post( $GLOBALS['wp_the_query']->get_queried_object() );

    // Lets get the first taxonomy's terms belonging to the post
    $terms_1 = get_the_terms( $current_post, $taxonomy_1 );

    // Set a varaible to hold the post count from first query
    $count = 0;
    // Set a variable to hold the results from query 1
    $q_1   = [];
    // Set a variable to hold the exclusions
    $sticky = get_option( 'sticky_posts' );
    $exclude = array_merge( [$current_post->ID], $sticky );
    $exclude = array_merge( $exclude, $recent_posts );

    // Make sure we have terms
    if ( $terms_1 ) {
        // Lets get the term ID's
        $term_1_ids = wp_list_pluck( $terms_1, 'term_id' );

        // Lets build the query to get related posts
        $args_1 = [
            'post_type'      => $current_post->post_type,
            'post__not_in'   => $exclude,
            'posts_per_page' => $total_posts,
            'fields'         => 'ids',
            'tax_query'      => [
                [
                    'taxonomy'         => $taxonomy_1,
                    'terms'            => $term_1_ids,
                    'include_children' => false
                ]
            ],
        ];
        $q_1 = get_posts( $args_1 );

        // Update our counter
        $count = count( $q_1 );
        // Update our counter
        $exclude = array_merge( $exclude, $q_1 );
    }

    // We will now run the second query if $count is less than $total_posts
    if ( $count < $total_posts ) {
        $terms_2 = get_the_terms( $current_post, $taxonomy_2 );
        // Make sure we have terms
        if ( $terms_2 ) {
            // Lets get the term ID's
            $term_2_ids = wp_list_pluck( $terms_2, 'term_id' );

            // Calculate the amount of post to get
            $diff = $total_posts - $count;

            $args_2 = [
                'post_type'      => $current_post->post_type,
                'post__not_in'   => $exclude,
                'posts_per_page' => $diff,
                'fields'         => 'ids',
                'tax_query'      => [
                    [
                        'taxonomy'         => $taxonomy_2,
                        'terms'            => $term_2_ids,
                        'include_children' => false
                    ]
                ],
            ];
            $q_2 = get_posts( $args_2 );

            if ( $q_2 ) {
                // Merge the two results into one array of ID's
                $q_1 = array_merge( $q_1, $q_2 );

                // Update our post counter
                $count = count( $q_1 );

                // Update our counter
                $exclude = array_merge( $exclude, $q_2 );
            }
        }
    }

    // We will now run the third query if $count is less than $total_posts
    if ( $count < $total_posts ) {
        // Calculate the amount of post to get
        $diff = $total_posts - $count;

        $args_3 = [
            'post_type'      => $current_post->post_type,
            'post__not_in'   => $exclude,
            'posts_per_page' => $diff,
            'fields'         => 'ids',
        ];
        $q_3 = get_posts( $args_3 );

        if ( $q_3 ) {
            // Merge the two results into one array of ID's
            $q_1 = array_merge( $q_1, $q_3 );
        } else {
            $args_4 = [
                'post_type'      => 'any',
                'post__not_in'   => $exclude,
                'posts_per_page' => $diff,
                'fields'         => 'ids',
            ];
            $q_4 = get_posts( $args_4 );

            if ( $q_4 ) {
                // Merge the two results into one array of ID's
                $q_1 = array_merge( $q_1, $q_4 );
            }
        }
    }

    // Make sure we have an array of ID's
    if ( !$q_1 )
        return false;

    // Run our last query, and output the results
    $final_args = [
        'ignore_sticky_posts' => 1,
        'post_type'           => 'any',
        'posts_per_page'      => count( $q_1 ),
        'post__in'            => $q_1,
        'order'               => 'ASC',
        'orderby'             => 'post__in',
        'suppress_filters'    => true,
        'no_found_rows'       => true
    ];
    $final_query = new WP_Query( $final_args );

    return $final_query;
}

Upvotes: 1

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