angular - Dynamically changing validation requirements between form elements in directives
The ng-required actually accept an expression, so there is no need to add {{ .. }} around the variable, otherwise the expression will be evaluated only once at a compile time.
In the textFormElement.html template, change this line:
ng-required="{{contentFragment.required}}"to this:
ng-required="contentFragment.required"Plunker: http://plnkr.co/edit/YLInikMU5Dl2hIpHPauy?p=preview
Hope this helps.