Angularjs: validation not working when control is based on directive

Question

Being rather new to Angularjs, I am creating textbox-label combinations in Angularjs using directives. It's working very well, but I can't get validation to work. Here is a stripped-down example.

The Html:

<form name="form" novalidate ng-app="myapp">
<input type="text" name="myfield" ng-model="myfield" required />{{myfield}}
<span ng-show="form.myfield.$error.required">ERROR MSG WORKING</span> 
<br>
<div mydirective FIELD="myfield2" />
</form>

The Javascript:

var myapp = angular.module('myapp', []);

myapp.directive('mydirective', function () {
    return {
        restrict: 'A',
        scope: { ngModel: '=' },
        template: '<input type="text" name="FIELD" ng-model="FIELD" />{{FIELD}}
        <span ng-show="form.FIELD.$error.required">ERROR MSG NOT WORKING</span>'
    };
});

The hard coded input - myfield - works, the other - myfield2 - doesn't (the binding does, just not the required-error message).

How do I tell the ng-show attribute to sort of "replace" FIELD in form.FIELD.$error.required by myfield2?

Here is a jsFiddle.

Answer 1

The problem is that your directive creates a new scope for the directive, this new scope does not have access to the form object in the parent scope.

I came up with two solutions, though I suspect there is a more elegant "Angular" way to do this:

Passing down the form object

Your view becomes:

<div mydirective FIELD="myfield2" form="form" />

And the scope definition object:

return {
    restrict: 'A',
    scope: {
        ngModel: '=',
        form: '='
    },
    template: '<input type="text" name="FIELD" ng-model="FIELD" required/>{{FIELD}}<span ng-show="form.FIELD.$error.required">ERROR MSG NOT WORKING</span>'
};

I've updated the fiddle with this code: http://jsfiddle.net/pTapw/4/

Using a controller

return {
    restrict: 'A',
    controller: function($scope){
        $scope.form = $scope.$parent.form;   
    },
    scope: {
        ngModel: '='
    },
    template: '<input type="text" name="FIELD" ng-model="FIELD" required/>{{FIELD}}<span ng-show="form.FIELD.$error.required">ERROR MSG NOT WORKING</span>'
};