I'working on plugin for custom post types and it's metadata etc. Everything is fine so far but now I need to extend this plugin - I need to create one extra the same custom post on save/edit post when certain metadata has value X. And I'm stucked to figure out how to get 2 values: 1)Insert "Parent" post ID to "Child" post to specific metadata 2)Insert "Child" post ID to "Parent" post to specific metadata

Here is code:

add_action('save_post', array($this, 'save_post_type_example_meta_boxes'));
function save_post_type_example_meta_boxes($post_id)
   ..........
  if (...) {
    $new_custom_post = array(
                'post_title'    => $title,
                'post_content'  => '',
                'post_status'   => 'publish',
                'post_author'   => 1,
                'post_type'   => 'custom_post_type',
                'meta_input'   => array(
                    'meta_1' => 'X',
                    'parent_post_id' => ???
                  ),
    );
    wp_insert_post($new_custom_post );
  }
  update_post_meta($post_id, 'child_post_id', ???);
  ......
  if(isset($_POST['meta_x_post'])) {
        $meta_x = sanitize_text_field($_POST['meta_x_post']);
        update_post_meta($post_id, 'meta_x', $meta_x);
    }
...
}

here it could be $post_id (because it's the ID for Parent post)?

Any suggestions how to get Child post ID?

Thank you!

I'working on plugin for custom post types and it's metadata etc. Everything is fine so far but now I need to extend this plugin - I need to create one extra the same custom post on save/edit post when certain metadata has value X. And I'm stucked to figure out how to get 2 values: 1)Insert "Parent" post ID to "Child" post to specific metadata 2)Insert "Child" post ID to "Parent" post to specific metadata

Here is code:

add_action('save_post', array($this, 'save_post_type_example_meta_boxes'));
function save_post_type_example_meta_boxes($post_id)
   ..........
  if (...) {
    $new_custom_post = array(
                'post_title'    => $title,
                'post_content'  => '',
                'post_status'   => 'publish',
                'post_author'   => 1,
                'post_type'   => 'custom_post_type',
                'meta_input'   => array(
                    'meta_1' => 'X',
                    'parent_post_id' => ???
                  ),
    );
    wp_insert_post($new_custom_post );
  }
  update_post_meta($post_id, 'child_post_id', ???);
  ......
  if(isset($_POST['meta_x_post'])) {
        $meta_x = sanitize_text_field($_POST['meta_x_post']);
        update_post_meta($post_id, 'meta_x', $meta_x);
    }
...
}

here it could be $post_id (because it's the ID for Parent post)?

Any suggestions how to get Child post ID?

Thank you!

• plugins
• wp-insert-post
• save-post

• When you insert a post, the ID of the new post is returned. – Milo Commented Oct 19, 2018 at 12:43

1 Answer 1

Here's an updated version of your code:

add_action('save_post', array($this, 'save_post_type_example_meta_boxes'));
function save_post_type_example_meta_boxes($post_id)
..........

    if (...) {
        $new_custom_post = array(
            'post_title'    => $title,
            'post_content'  => '',
            'post_status'   => 'publish',
            'post_author'   => 1,
            'post_type'   => 'custom_post_type',
            'meta_input'   => array(
                'meta_1' => 'X',
                'parent_post_id' => $post_id,
            ),
        );

        // Prevent this action from running twice.
        remove_action( 'save_post', [ $this, 'save_post_type_example_meta_boxes' ] );
        $child_post_id = wp_insert_post( $new_custom_post );
        // Readd the action.
        add_action('save_post', array($this, 'save_post_type_example_meta_boxes'));
    }

    update_post_meta($post_id, 'child_post_id', $child_post_id);
    ......
    if(isset($_POST['meta_x_post'])) {
        $meta_x = sanitize_text_field($_POST['meta_x_post']);
        update_post_meta($post_id, 'meta_x', $meta_x);
    }
...
}

And here's what I changed:

• The incoming post ID to save_post_type_example_meta_boxes should be what you want to use as your "parent" post ID.
• You should temporarily remove your hook to save_post so that it doesn't try to run on that action over and over again.
• As noted by @Milo, wp_insert_post returns a post ID on success, so that would give you the "child" post ID.