This widget is used to resolve an issue with the Reference Form that corrects fields not appearing when an existing reference is edited with the form. This patch overrides the form's built in show on select feature, which has an issue displaying the proper fields when editing an existing reference.
The widget will trigger an event that adds the CSS class .editOverride to the related document type fields when the Edit with form button is used. Changing the form's document type selection will remove the override class and the show on select feature will work in normal fashion.
This bug appears to have been introduced when using multiple nested show on select events were added to the form.
This widget is called at the bottom of the Reference Form and should only be used with this form.