Webhook: save_post action fires wp_remote_post twice

Question

I am trying to implement a webhook in a plugin which should fire everytime a user saves a post. It works fine, but I recive two requests on frontend api. The first request has got a wrong slug. I wonder why this is happening or what I am doing wrong here. The second call works perfect.

 defined('ABSPATH') or die('Unauthorized access');

 add_action('save_post', 'update_front_end', 10, 2);
 function update_front_end($post_id, $post){

   $exovias_webhooks_options = get_option( 'exovias_webhooks_option_name' ); // Array of All Options
   $secret_0 = $exovias_webhooks_options['secret_0']; // Secret
   $frontendurl_1 = $exovias_webhooks_options['frontendurl_1']; // FrontendUrl

 
  $slug = basename(get_permalink($post_id));
  $url = $frontendurl_1 . '/api/revalidate?secret=' . $secret_0 .'&slug=' . $slug;

   wp_remote_post($url);

}

Answer 1

I wonder why this is happening or what I am doing wrong here

WordPress has a revisions system which stores a record of each saved draft or published update, and a post can have one of a number of statuses like auto-draft when a new post is created and saved automatically in the background, draft (e.g. when the post is autosaved) or publish (e.g. when the publish button is clicked). So the save_post hook (and other hooks like wp_after_insert_post) can run multiple times while editing a post, and thus you should check whether WordPress is doing an autosave and whether the post being saved is a revision, before running your remote HTTP request.

Here's an example which also checks whether WordPress is doing cron (/wp-cron.php) or AJAX (wp-admin/admin-ajax.php), and whether the post status is publish or private:

function update_front_end( $post_id, $post ) {
    $doing_autosave = ( defined( 'DOING_AUTOSAVE' ) && DOING_AUTOSAVE );

    if ( $doing_autosave || wp_is_post_revision( $post_id ) ||
        wp_doing_cron() || wp_doing_ajax()
    ) {
        return;
    }

    if ( in_array( $post->post_status, array( 'publish', 'private' ) ) ) {
        // your code here; define the $url, etc.

        // now run your remote HTTP request
        wp_remote_post( $url );
    }
}