Filter Nooz posts by custom-field values

functions.php

<?php

/**
 * The solution below allows you to filter Nooz posts by custom-field values.
 *
 *   1. Enable support for "custom-fields"
 *   2. Add a custom field variable to a press release post, in the example below, the variable is "lang_type"
 *   3. Use the "class" attribute to determine which shortcode instance gets filtered, in the example below, shortcodes using "class='lang-es'"
 */

/**
 * Add support for "custom-fields" to the "nooz_release" post type.
 */
add_filter( 'nooz/post-types/nooz_release/options', function( $args ) {
    $args['supports'][] = 'custom-fields';
    return $args;
} );

/**
 * Check for shortcodes using "class='lang-es'" and filter posts.
 */
add_filter( 'nooz_posts_query_options', function( $query_options, $atts ) {
    if ( FALSE !== strpos( $atts['class'], 'lang-es' ) ) {
        $query_options['meta_key'] = 'lang_type';
        $query_options['meta_value'] = 'es';
    }
    return $query_options;
}, 10, 2 );