$watch on clientWidth isn't working - angularjs

Question

Inside of my directive I have this and it works only in the beginning, and whenever I resize later it never fires.
scope.$watch ->
cw: element[0].clientWidth
,(newValue, oldValue)->
if newValue.cw isnt oldValue.cw
console.log "changed"
,true

Answer 1

Your function looks right to me, but it's important to note that it won't fire on resize unless you manually trigger a digest on the resize event.
Without this, angular doesn't realise there's been an event that should trigger a digest, and so none happen.
Try adding this (remember to inject $window):
angular.element($window).bind('resize', ()->
scope.$apply();
)

Answer 2

Just like Jason Goemaat said, its because Watches are only checked on a $digest cycle
Depending on how the way your element is resized maybe this example may help you.
Here is a menu that expands it self when pressed on the arrow.
<div class="menu" ng-class="{'expanded' : main.expanded}">
<div class="menu-handler" ng-click="main.expanded = !main.expanded">
</div>
</div>
The menu is expanded by a ng-click that makes a change on the scope, in this case its a boolean var that acts as a flag. As the opening of the menu is made throught the change in the scope it calls the $digest cycle iterating through all $watch.
scope.$watch(function() {
return element[0].clientWidth;
}, function(oldValue, newValue) {
console.log(oldValue, newValue);
});
You can view the full example in this JSfiddle
https://jsfiddle.net/owenbcal/zf17s0mL/
Hope i was helpfull.

Answer 3

the way I know about watching this kind of values is making a function that is fired once the value changes so then I watch that function :
in the service:
this.getDataOut = function () {
return self.dataOut;
};
in the controller:
$scope.$watch(dataService.getDataOut, function() {
$scope.dataOut = dataService.dataOut;
});