How to extend field visibilty rule?

[regesh]

Any field has visibility option (showif) that works perfect with field in current template. But i need to compare with the field in parent page template. Is it possible?
The task is like that: I have multiselect field in parent page - it is "Page Refference" field.   And i need field in children page compare that there is some page selected in parent multiselect field for it to show in editor.

[elabx]

Maybe something like this, but I'm not entirely sure it will work, place it on ready.php:

$wire->addHookBefore('Inputfield::render', function($event){
  // the field where the field to hide exists
  $page = $inputfield->hasPage;
  $inputfield = $event->object;
  if($inputfield->name != "field_to_hide_if_parent") return;

  if($page->id){
    // maybe check for children of specific type?
    if($page->parent->template == "specific_type_of_page"){
      // the condition on the parent page?
      if($page->parent->multiselect_field->name == "some-name"){
          $inputfield->collapsed = Inputfield::collapsedHidden;
      }
	}
  }
});

[DV-JF]

@regesh Have a look at https://processwire.com/modules/custom-inputfield-dependencies/ You'll have multiple options to configure the visibility of fields and even the possibility to mark them as required if your selector is matching. It adds following options to the fields:

 

[regesh]

oO! Thanks a lot guys!