The automatic Related Forms capability is only available for forms that are based on the VPM Enterprise Form_Toolbar class or subclasses. All VPM Enterprise form classes that use the VPM Enterprise Form Toolbar are subclasses of the Form_Toolbar class.
Related Pages Form – Parent but Not Child
A VPME Related Pages form (see ProMatrix Related Pages Form Builder) may be a Related Forms parent but not a Related Forms Child.
One-to-Many Form as Child
A One-to-Many form can be a child Related Form, but the Parent Mode functionality of the Toolbar is disabled for technical reasons involving the child grids.
Editable Grid as Child Related Form
A form that contains an editable grid constructed with the ProMatrix Grid Builder (see ProMatrix Grid Builder – an Editable Grid) can be a child Related Form if it’s set up properly. See Editable Grid as Child Related Form to learn how to set up a form with an editable grid to function as a child Related Form.