Profile: John Johansen

Problem: In a CRED form that creates child posts, I would like to filter the options shown in a generic field based on other posts in its hierarchy.

Solution: If you know the grandparent ID in the context of the CRED form you can then pass that value into a View's filter using a shortcode attribute. That View can have a post relationship filter, where the parent is set by a shortcode attribute. The output of that View can be used to define the options for your generic select field.

You can access URL parameters with this shortcode:

add_shortcode( 'wpv-post-param', 'wpv_post_param_shortcode' );
 
function wpv_post_param_shortcode( $atts ) {
  if ( !empty( $atts['var'] ) ) {
    $var = (array)$_GET[$atts['var']];
    return esc_html( implode( ', ', $var ) );
  }
}

For example, if your type D CRED form is accessed at a URL like yoursite.com/new-post-type-d?a=12345, then you can access the type a ID (12345) like so:

[wpv-post-param var='a']

You can then pass that URL parameter into a View as a shortcode attribute:

[wpv-view name="some-view" wpvb="[wpv-post-param var='a']"]

With that approach, you can filter "some-view" using the post type A id from the URL parameter.

Relevant Documentation:
https://toolset.com/documentation/user-guides/passing-arguments-to-views/