How to pass authentication data through REST API requests

By default, the WordPress REST API doesn’t pass along authentication data.

If your FacetWP template or customization code depends on the currently logged-in user, you will run into issues with your code not working after an AJAX refresh is triggered (which happens when using facets).

Examples would be code that depends on:

• is_user_logged_in()
• wp_get_current_user()
• global $current_user and e.g. $current_user->roles

Fortunately, there’s an easy workaround: add the following code to your (child) theme’s functions.php:

How to use custom PHP code?
PHP code can be added to your (child) theme's functions.php file. Alternatively, you can use the Custom Hooks add-on, or a code snippets plugin. More info
/*
  Please note that caching may interfere with the NONCE,
  causing AJAX requests to fail. Please DISABLE CACHING for facet pages,
  or set the cache expiration to < 12 hours!
*/

add_action( 'wp_footer', function() {
  ?>
    <script>
      document.addEventListener('facetwp-loaded', function() {
        if (! FWP.loaded) { // initial pageload
          FWP.hooks.addFilter('facetwp/ajax_settings', function(settings) {
            settings.headers = { 'X-WP-Nonce': FWP_JSON.nonce };
            return settings;
          });
        }
      });
    </script>
  <?php
}, 100 );

See also

• FacetWP REST API
• Using FacetWP with the WordPress REST API Authentication plugin