javascript - AngularJS custom form validation directive doesn't work in my modal

Question

I decided to write a custom directive to help me validate my input boxes. The idea is that I add my new fancy nx-validate directive to a bootstrap div.form-group and it'll check whether my <input/> is $dirty or $invalid and apply the .has-success or .has-error class as required.

For some odd reason, my directive works perfectly under normal circumstances, but the added ng-class is completely ignored inside a ui-bootstrap modal.

Identical code in both the modal and the form

<form name="mainForm">
  <div class="row">
      <div nx-validate class="form-group has-feedback col-lg-6 col-md-6 col-xs-12">
          <label class="control-label">Green if long enough, red if not</label>
          <input type="text" id="name" class="form-control" ng-model="property.name" required="required" ng-minlength="5"/>
          (once touched I do change colour - happy face)
      </div>
  </div>        

And my lovely directive

nitro.directive("nxValidate", function($compile) {
    return {
        restrict: 'A',
        priority: 2000,
        compile: function(element) {

            var node = element;
            while (node && node[0].tagName != 'FORM') {
                console.log (node[0].tagName)
                node = node.parent();
            }
            if (!node) console.error("No form node as parent");
            var formName = node.attr("name");
            if (!formName) console.error("Form needs a name attribute");


            var label = element.find("label");
            var input = element.find("input");
            var inputId = input.attr("id")

            if (!label.attr("for")) {
                label.attr("for", inputId);
            }

            if (!input.attr("name")) {
                input.attr("name", inputId);
            }

            if (!input.attr("placeholder")) {
                input.attr("placeholder", label.html());
            }

            element.attr("ng-class", "{'has-error' : " + formName + "." + inputId + ".$invalid && " + formName + "." + inputId + ".$touched, 'has-success' : " + formName + "." + inputId + ".$valid && " + formName + "." + inputId + ".$touched}");
            element.removeAttr("nx-validate");

            var fn = $compile(element);

            return function($scope) {
                fn($scope);
            }

        }
    }
});

Check it out on plunker: http://plnkr.co/edit/AjvNi5e6hmXcTgpXgTlH?

Answer 1

The simplest way I'd suggest you is you can put those classes by using watch on those fields, this watcher will lie inside the postlink function after compiling a DOM

return function($scope, element) {
    fn($scope);

    $scope.$watch(function(){
      return $scope.modalForm.name.$invalid && $scope.modalForm.name.$touched;
    }, function(newVal){
      if(newVal)
        element.addClass('has-error');
      else
        element.removeClass('has-error');
    })

    $scope.$watch(function(){
      return $scope.modalForm.name.$valid && $scope.modalForm.name.$touched;
    }, function(newVal){
      if(newVal)
        element.addClass('has-success');
      else
        element.removeClass('has-success');
    })
}

Demo Here

Update

The actual better way of doing this would be instead of compiling element from compile, we need $compile the element from the link function itself. The reason behind the compiling DOM in link fn using $compile is that our ng-class attribute does contain the scope variable which is like myForm.name.$invalid ,so when we $compile the DOM of compile function then they are not evaluating value of myForm.name.$invalid variable because compile don't have access to scope & the would be always undefined or blank. So while compile DOM inside the link would have all the scope values are available that does contain myForm.name.$invalid so after compiling it with directive scope you will get your ng-class directive binding will work.

Code

compile: function(element) {
    //..other code will be as is..

    element.removeAttr("nx-validate");
      //var fn = $compile(element); //remove this line from compile fn
      return function($scope, element) {
         //fn($scope);
         $compile(element)($scope); //added in postLink to compile dom to get binding working
      }
 }

Updated Plunkr