angularjs - Angular JS - How can I get the ngModelController by its model name? -

In my custom command, I need to update the validity of another input. The instruction is something like this:
& lt; CustomDirective = "foo" & gt; , in which the value foo is the name of the other ngmodel.

My director, I can get the model of this like this:
var foo = scope [attrs.foo];

But how can I get its NGMDL controller to determine its validity? Just like this: fooModelController $ SetValidity ('custom directive' is true);

Edit:

In HTML, the input is defined:

  & lt; Input type = "text" name = "dateDebut" id = "dateDebut" class = "form-control" ng-model = "formData.dateDebut" customDirective = "dateFin" required & gt; & Lt; Input type = "text" name = "dateFin" id = "dateFin" class = "form-control" ng-model = "formData.dateFin" customDirective = "dateDebut" required & gt;  

I get the dome node by angular.element.find (document.querySelctor ('# dateDebut')) ;

angular Element (document.querySelctor ('# dateDebut')) controller ('ngModel') - This will be given on the ngModelController defined #dateDebut element.

Here is plnkr: