Loads different templateUrl depending on a scope variable

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

app.controller('MainCtrl', function($scope) {
    // Change this
    // TODO make this demo interactive from view
    $scope.myScopeVariable = true;
    $scope.send_message = function () {
      alert ("message.text");
    }
});

app.directive('myDirective', ['$compile', '$http', '$templateCache',function($compile, $http, $templateCache) {
	        var getTemplate = function(contentType) {
	            var templateLoader,
	            templateMap = {
	                ok: 'ok.html',
	                not_ok: 'not_ok.html',
	            };

	            var templateUrl = templateMap[contentType];
	            templateLoader = $http.get(templateUrl, {cache: $templateCache});

	            return templateLoader;
	        }

	        var linker = function(scope, element, attrs) {
	        	var template = (attrs.isOk)?'ok':'not_ok';
	            var loader = getTemplate(template);
	            var promise = loader.success(function(html) {
	                element.html(html);
	            }).then(function (response) {
	                element.replaceWith($compile(element.html())(scope));
	            });
	        }

	        return  {
			       restrict: 'E',
			       templateUrl: 'not_ok.html',
			       link: linker
			   };
		}]);

<!DOCTYPE html>
<html ng-app="plunker">

  <head>
    <meta charset="utf-8" />
    <title>AngularJS Plunker</title>
    <script>document.write('<base href="' + document.location + '" />');</script>
    <link rel="stylesheet" href="style.css" />
    <script data-require="angular.js@1.2.x" src="https://ajax.googleapis.com/ajax/libs/angularjs/1.2.17/angular.js" data-semver="1.2.17"></script>
    <script src="app.js"></script>
  </head>

  <body ng-controller="MainCtrl">
    <p>myValue <b>{{myValue}}</b></p>
    <my-directive is-ok="{{myScopeVariable}}"></my-directive>
    <form>
    <input type="text" ng-model="bodymessage.text">
    <button ng-click="send_message(bodymessage)">Submit</button>
  </form>
  </body>

</html>

/* Put your css in here */

.true {
  color:green;
}
.false {
  color:blue;
}

<div class="true">
<div>OK</div>
  <form>
    <input type="text" ng-model="message.text">
    <button ng-click="send_message(message)">Submit</button>
  </form>
</div>

<div class="false">NOT OK</div>