Variable value not passing in a controller using directive with ng-class - angularjs

Question

I am referencing the value of the variable in a controller in an ng-class template but its not working.
here is the html directive template URl :
<div class="tooltip-anchor">
<div class=" tooltip-content ehub-body" ng-class="{ 'tooltip__content--disabled': tooltipContentValue}" ng-transclude>Tooltip content</div>
</div>
Here is where i am using the directive in the index page
<div style="text-align:center;">
<ehub-tooltip>Hello i am here, and i am her to stay</ehub-tooltip>over here
<ehub-tooltip>Be nice to people on your way up and they will be nice to you on your way down</ehub-tooltip>click me
</div>
And here is the directive:
in this directive i am creating a variable and setting it to false and also trying to use it in an ng-class attribute
(function (window) {
'use strict';
angular
.module('ehub.component.tooltip', [])
.controller('ehubTooltipCtrl', ['$scope', function ($scope) {
$scope.tooltipContentValue = false;
}])
.directive('ehubTooltip', ehubTooltip);
function ehubTooltip() {
var directive = {
controller: "ehubTooltipCtrl",
link: link,
transclude: true,
templateUrl: 'ehub-tooltip.html',
restrict: 'E'
};
return directive;
function link(scope, element, attrs) {
scope.keyupevt = function () {
if (event.keyCode === 27) {
$scope.tooltipContentValue = true;
}
}
}
}
})();

Answer 1

Try this working jsfiddle.
angular.module('ExampleApp', ['ngMessages'])
.controller('ExampleController', function($scope) {
})
.directive('ehubTooltip', function() {
var directive = {
link: link,
transclude: true,
template: '<div class="tooltip-anchor"><div class=" tooltip-content ehub-body" ng-class="{ \'tooltip__content--disabled\': tooltipContentValue}" ng-transclude>Tooltip content</div></div>',
restrict: 'E'
};
function link(scope, element, attrs) {
scope.tooltipContentValue = false;
scope.keyupevt = function() {
if (event.keyCode === 27) {
scope.tooltipContentValue = true;
}
}
}
return directive;
});
<script src="https://ajax.googleapis.com/ajax/libs/angularjs/1.2.23/angular.min.js"></script>
<div ng-app="ExampleApp">
<div ng-controller="ExampleController">
<div style="text-align:center;">
<a href="" ng-keyup="keyupevt()">
<ehub-tooltip>Hello i am here, and i am her to stay</ehub-tooltip>over here</a>
<a href="" ng-keyup="keyupevt()">
<ehub-tooltip>Be nice to people on your way up and they will be nice to you on your way down</ehub-tooltip>click me</a>
</div>
</div>
</div>