Pre-populating post object field no longer works, while other fields do

• pekka

• August 18, 2018 at 2:45 am

I have a custom post type with a post object field and a number of other fields.

I need to pre-populate some of the fields when the user creates a new post, including the post object field.

This used to work fine but then the post object field stopped accepting the pre-populated value.

At the moment, as part of the debugging effort, I am using this piece of code in functions.php:

add_action( 'load-post-new.php', 'wpse8650_post_new' );

function wpse8650_post_new()
{ 
	add_action( 'wp_insert_post', 'wpse8650_wp_insert_post_default' );
}

function wpse8650_wp_insert_post_default( $post_id )
{

	if ($_REQUEST["new_post_prefill"] == "yes")
	{
           // DROPDOWN, WORKS
           add_post_meta( $post_id, 'type', "Short conversation" );
           // TEXT FIELD, WORKS
   	   add_post_meta( $post_id, 'customer', "Imaginary customer name" ); 
           // POST OBJECT FIELD, DOESNT WORK
	   add_post_meta( $post_id, 'parent_post', 1234); 
	   
    }

}

The fields “type” and “customer” are pre-filled with the strings I specified in the code above, but the post object field (parent_post) does not accept the post ID I pass to it (which is 100% a correct, functioning post ID which I can select manually in the post object menu and save – it’s just the automatic pre-populating that doesn’t work).

The post object field is configured to return the post ID rather than the post object.

As I said, it used to work for the post object field until a while ago. Unfortunately I do not know what changed.

Any ideas on why this would not work?

• pekka

• August 18, 2018 at 2:50 am

I just created another post object field in the same form and that works fine: I can do a add_post_meta( $post_id, 'temporary_second_post_object_field', $_REQUEST['my_post_id'] ); and the field assumes that value with no problems!

I suppose deleting the original field and recreating it might work, but I can’t really afford to do that, I’ve got hundreds of values in it that I’d have to painstakingly restore somehow…. also I suppose this might happen again any time.

Could this be some obscure bug, then?

• pekka

• August 22, 2018 at 12:25 am

OK – not sure why, but ditching add_post_meta() / update_post_meta() in favour of ACF’s own update_field appears to work fine!

add_action( 'load-post-new.php', 'wpse8650_post_new' );

function wpse8650_post_new()
{ 
	add_action( 'wp_insert_post', 'wpse8650_wp_insert_post_default' );
}

function wpse8650_wp_insert_post_default( $post_id )
{

	if ($_REQUEST["new_post_prefill"] == "yes")
	{
          
           update_field('type', "Short conversation",  $post_id );
      
   	   update_field( 'customer', "Imaginary customer name",  $post_id  ); 
       
	   update_field('parent_post', 1234,  $post_id ); 
	   
    }

}

• John Huebner

• August 22, 2018 at 11:31 pm

The reason it does not work is that you are not creating a acf field reference when using update_post_meta(). Without the field key reference ACF does not know that the value you entered is for a relationship field. When you use update_field() acf creates the key reference.

• YorlinqNL

• October 20, 2020 at 5:01 pm

@pekka I’m trying to accomplish pretty much the same thing.

I have a repeater field with 2 subfields (1 of them is a Post Object field) and I want to pre populate them when creating a new post.

What was the complete code you used?

PS. Do I need the code within ‘load-post-new.php’ too?

tnx