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<?php
/**
 * Grab text block by shortcode
 *
 * @param array $shortcode Shortcode for the required textblock
 * @return WP_REST_Response|WP_Error Text block in response object or error if not found
 */

function ifour_get_text_block( $request ) {
    $items = new WP_Query([
        'post_type'         => 'text-blocks',
        'name'              => $request['field'],
        'posts_per_page'    => 1,
        'post_status'       => 'publish'
    ]);

    if (! $items->have_posts() ) {
        return new WP_Error( 'no_text_block_found', 'Invalid text-block request', array( 'status' => 404 ) );
    }

    // Build up the response object
    $response = new WP_REST_Response($items->get_posts());

    // // Add a custom status code
    $response->set_status(200);

    // Add some headers
    $response->header('X-WP-Total', $items->found_posts );
    $response->header('X-WP-TotalPages', $items->max_num_pages);

    return $response;
}

add_action( 'rest_api_init', function () {
  register_rest_route( 'ifour/v1', '/text-blocks/(?P<field>[\\w\\-\\_]+)', array(
    'methods' => 'GET',
    'callback' => 'ifour_get_text_block',
  ));
});