I assume you migrated the Custom Post Types relationships to the new Many to Many structures since you use the beta Types version, correct?
Hence, the old API will not be correct to use anymore, and that code snippet is based on the old API.
There is a new API, which you can use to craft your custom code snippets:
https://toolset.com/documentation/customizing-sites-using-php/post-relationships-api/
We do not craft custom code as you request it here.
We cannot make it "so it's adapted to your case".
But, we can give the correct example and information about the API, and with your knowledge of PHP and WordPress API, you can then craft custom code as per needs.
Let me show you another code that does exactly the same.
The example that Noman gives is wrong, it uses a wpv_ prefix, something that is reserved to Toolset ShortCodes and should never be used elsewhere as a prefix.
What if we ever were to add such a ShortCode to our code base? Accidentally, given that we prefix all our ShortCodes with a "wpv_" prefix in the PHP, it might then conflict!
It's hence better to craft the own, particularly prefixed codes for your specific site/theme/plugin.
This was my example when you use the Old API.
https://toolset.com/forums/topic/conditional-user-has-post-with-parent-current-page/
/**
*Count child posts of given type
*/
function child_post_count() {
$post_id = $post->ID; //get current post ID
$child_post_count = count( get_posts( array(
'post_type' => 'your_child_post_type_slug', //child post type
'meta_key' => '_wpcf_belongs_your-parent-post-type-slug_id',
'meta_value' => $post_id,
) ) );
return $child_post_count;//this returns a numerical value of Posts that are of "child" type, and child of the $post_id
}
This worked with the old Relationships
With the Types beta, or even Types 2.2.22 you can already use the new API:
https://toolset.com/documentation/customizing-sites-using-php/post-relationships-api/#toolset_get_related_posts
To help you craft this code sample, I need to know the exact nature of your Post Relationship.
Has this relationship been set up with the old Types and now has been migrated to new Types, or, is this a complete newly set up relationship?
The function you will use will look something like this:
function child_post_count() {
//get the posts
$books = toolset_get_related_posts(
$writer, // in your case this is learning-program
array( 'writer', 'book' ), // service-provider and learning-program
'child', // get posts where $writer is the child in given relationship
$posts_per_page, $current_page, // pagination
array( ), // nothing to filter additionally by
'post_object'
);
//Count those posts
$amount = count($books->ID);
//return the value
return $amount;
}
