You could just use ng-disabled and ng-required, instead of adding the attributes in a directive.
<div>
<label for="username">username2</label>
<input ng-model="data.account.username2"
ng-disabled="paintData['data.account.username2'] == 'RO'"
ng-required="paintData['data.account.username2'] == 'R'" />
</div>
Alternatively, you could define a directive template that uses ng-disabled and ng-required, and replace the original element with it:
.directive('metaValidate', function($compile) {
return {
restrict: 'A',
replace: true,
scope: {
model: '=',
paint: '='
},
template: '<input ng-model="model" ng-disabled="readonly" ng-required="required"/>',
link: function(scope, element, attrs) {
scope.required = scope.paint[element.attr('model')] === 'R';
scope.readonly = scope.paint[element.attr('model')] === 'RO';
}
};
});
Then, use it like this:
<input model="data.account.username2" meta-validate paint="paintData"/>
I prefer the first approach, because it can respond to changes to paintData. But, you have to repeat the property name several times.
If you want to try this code, here is an update of your Plunker.