Let Users Filter Posts by Custom Fields

Question

I'm using the Advanced Custom Fields plugin to add custom fields to my posts, but was wondering what is the best way to go about creating a filter box for the user to filter through posts.

I've been using the pre_get_posts action in WordPress to alter the meta query like so http://www.website.com/cars?type=saloon,couple,SUV. But I've found that when I start using multiple queries the website begins to hang and it's pretty slow.

Does anyone know if there's a better way to do this. I simply want my users to be able to filter through cars with relative ease. Am I going about this the wrong way?

Any help is appreciated. Thanks in advance!

Answer 1

Have you ever try to use 'custom taxonomy' to categorize the cars? I think taxonomy should be a more proper way to do this.

You could register car brands like:

// Register Custom Taxonomy
function wpse_131586_custom_taxonomy() {

    $labels = array(
        'name'                       => _x( 'Brands', 'Taxonomy General Name', 'wpse' ),
        'singular_name'              => _x( 'Brand', 'Taxonomy Singular Name', 'wpse' ),
        'menu_name'                  => __( 'Car Brands', 'wpse' ),
        'all_items'                  => __( 'All Items', 'wpse' ),
        'parent_item'                => __( 'Parent Item', 'wpse' ),
        'parent_item_colon'          => __( 'Parent Item:', 'wpse' ),
        'new_item_name'              => __( 'New Item Name', 'wpse' ),
        'add_new_item'               => __( 'Add New Item', 'wpse' ),
        'edit_item'                  => __( 'Edit Item', 'wpse' ),
        'update_item'                => __( 'Update Item', 'wpse' ),
        'separate_items_with_commas' => __( 'Separate items with commas', 'wpse' ),
        'search_items'               => __( 'Search Items', 'wpse' ),
        'add_or_remove_items'        => __( 'Add or remove items', 'wpse' ),
        'choose_from_most_used'      => __( 'Choose from the most used items', 'wpse' ),
        'not_found'                  => __( 'Not Found', 'wpse' ),
    );
    $args = array(
        'labels'                     => $labels,
        'hierarchical'               => true,
        'public'                     => true,
        'show_ui'                    => true,
        'show_admin_column'          => true,
        'show_in_nav_menus'          => true,
        'show_tagcloud'              => true,
    );
    //Change 'cars' to your post type accordingly
    register_taxonomy( 'car_brand', 'cars', $args );

}

// Hook into the 'init' action
add_action( 'init', 'wpse_131586_custom_taxonomy', 0 );

Hope you'll get the idea of registering a custom taxonomy for car types.