Show all custom post type posts sorted by custom taxonomy then by another custom taxonomy

Question

Sorry for confusing title. Not sure how to describe it better. I'd like to display all shops first sorted by theirs categories, then, inside it, sorted by their locations.

I have custom post type "Shop", two custom taxonomies "Shop Category", "Shop Location".

Example how I'd like it to display:

Shoes

London

• Shop 01
• Shop 02

Tokyo

• Shop 05
• Shop 06

Electronics

London

• Shop 11
• Shop 12

Tokyo

• Shop 15
• Shop 16

Shoes, Electronics, (...) - Taxonomy #1

London, Tokyo, (...) - Taxonomy #2

Shop 01, (...) - Custom Post Type

Got it working to show sorted by one taxonomy so far. It works good but I need one more level.

<?php
$custom_terms = get_terms('shop_category');
foreach ($custom_terms as $custom_term) {

wp_reset_query();
$args = array(
    'post_type' => 'shop',
    'tax_query' => array(
        array(
            'taxonomy' => 'shop_category',
            'field' => 'slug',
            'terms' => $custom_term->slug,
        ),
    ),
);

$loop = new WP_Query($args);
if($loop->have_posts()) {
    echo '<div class="box-category">'.$custom_term->name.'</div>';

    while($loop->have_posts()) : $loop->the_post();
        echo '<a href="'.get_permalink().'">'.get_the_title().'</a><br>';
    endwhile;
}

}
?>

Thanks in advance for directions.

Answer 1

First get a list of categories and a list of locations. Then loop through each category. Within each category loop through the list of locations and query posts that have the current category and the current location and output the list:

$categories = get_terms( array(
    'taxonomy' => 'shop_category',
) );

$locations = get_terms( array(
    'taxonomy' => 'shop_location',
) );

foreach ( $categories as $category ) {
    echo '<div class="box-category">' . $category->name . '</div>';

    foreach ( $locations as $location ) {
        $shops = new WP_Query( array(
            'post_type' => 'shop',
            'tax_query' => array(
                array(
                    'terms'    => $category->term_id,
                    'taxonomy' => 'shop_category',
                ),
                array(
                    'terms'    => $location->term_id,
                    'taxonomy' => 'shop_location',
                ),
            ),
        ) );

        if( $shops->have_posts() ) {
            echo '<div class="box-location">' . $location->name . '</div>';

            while ( $shops->have_posts() ) : $shops->the_post();
                echo '<a href="' . get_permalink() . '">' . get_the_title() . '</a><br>';
            endwhile;
        }

        wp_reset_postdata();
    }
}