How do I use $timeout service in a Directive?

Question

Basically, I want to measure the width of the element after angular has manipulated the DOM. So I would like to use $timeout for that, but it keeps getting me errors.

HTML

   <div ng-app="github">
      <ul mynav>
        <li ng-repeat="nav in navItems">{{nav.name}}</li>
      </ul>

      </div>
    </div>

CSS

ul,li {
  display:inline-block;
}
li {
  margin-right:1em;
}

JS

(function() {
  angular.module('github', [])
    .directive('mynav', function($window) {
      return {
        restrict: 'A',
        link: function(scope, element, attrs, timeout) {
          scope.navItems = [{
            "name": "home"
          }, {
            "name": "link1"
          }, {
            "name": "link2"
          }, {
            "name": "link3"
          }];
          timeout(function() {
            console.log($(element).width());
          })
        }

      }
    });
})();

Answer 1

link function isn't a correct place to inject dependency. It has defined sequence of parameter like I shown below. You can't put dependency there.

link(scope, element, attrs, controller, transcludeFn) {

Inject $timeout dependency in directive function.

(function() {
  angular.module('github', [])
    .directive('mynav', function($window, $timeout) { //<-- dependency injected here
      return {

Then just use injected $timeout inside link function

$timeout(function() {
    console.log(element.width());
})

Answer 2

Just replace timeout with setinterval like below:

(function() {
  angular.module('github', [])
    .directive('mynav', function($window) {
      return {
        restrict: 'A',
        link: function(scope, element, attrs, timeout) {
          scope.navItems = [{
            "name": "home"
          }, {
            "name": "link1"
          }, {
            "name": "link2"
          }, {
            "name": "link3"
          }];
          setInterval(function() { // replpace 'timeout' with 'setInterval'
            console.log($(element).width());
          })
        }

      }
    });
})();

Hope it works for you.

Answer 3

setInterval(function(){
    // code here
    $scope.$apply();
}, 1000); 

$apply is included as a reminder that since this is an external jQuery call you need to tell angular to update the DOM.

$timeout being an angular version automatically updates the DOM