query a relationship from another field in same post

• rudtek

• July 16, 2016 at 10:06 am

Is there a way to query the data from another field in the same post?

i.e. I have a post called events. and this post has a field called ‘event_speakers’. This relationship field is querying another CPT called ‘speakers’. I can choose all the speakers i want to attend this event fine. The question is now this:

I have another field that’s called ‘event_session’ Is there any way to have this pull ONLY the speakers that have been chosen in the ‘event_speakers’ field? (some filter maybe?)

The other option would be to make the ‘event_speakers’ field be a repeater that has some fields, and then have the ‘event_session’ pull from that speaker list. (avoiding the “speakers” CPT altogether)

• James

• July 17, 2016 at 2:39 pm

Hi @rudtek

I’m afraid I don’t understand your setup, so forgive me if I’m wrong. If you want to load the choices of a field dynamically from another field without reloading the page, then you need to use AJAX. This page should give you more idea about it: https://www.bobz.co/dynamically-populate-select-fields-choice-in-advanced-custom-fields/.

I’m afraid I can’t give you any advice regarding the repeater method because I don’t know your setup exactly. Could you please share some screenshots of it? Also, please share the JSON or XML export file of your field group too.

Thanks 🙂

• rudtek

• July 19, 2016 at 9:05 am

This reply has been marked as private.

• James

• July 20, 2016 at 4:46 pm

Hi @rudtek

I believe you can do it like this:

function my_post_object_query( $args, $field, $post_id ) {
	
    // Get the allowed post IDs from the relationship field
    $allowed_ids = get_field('event_speakers', $post_id, false);
    
    // Restrict the returned posts
    $args['post__in'] = $allowed_ids;
	
	// return
    return $args;
    
}

// filter for a specific field based on it's name
add_filter('acf/fields/post_object/query/name=session_speaker', 'my_post_object_query', 10, 3);
add_filter('acf/fields/post_object/query/name=session_moderator', 'my_post_object_query', 10, 3);
add_filter('acf/fields/post_object/query/name=session_emcee', 'my_post_object_query', 10, 3);
add_filter('acf/fields/post_object/query/name=session_host', 'my_post_object_query', 10, 3);

Please keep in mind that you need to save the post first after changing the speakers field.

I hope this helps 🙂