ngWatch.txt

$watch


//this is the value we are watching



vm.fooCount =0;




//When u watch a "vm.*" value from within the controller, you are making the assumption(ie, creating coupling) that your View is using the same variable - "vm" - externally that you are using intenally.

//Caution: In our case, this is not true - the view is using the 
 "appController" alias

$scope.watch(
		"vm.fooCount",
		function handleFooChange(newValue,oldValue){
			console.log("vm.fooCount: ", newvalue);
	});


//if your controller and your view are not using the same view-model 
//alias ,then you can explicitly watch the value that our view is using.
//Here we are wacyhing "appController" instead of "vm". This might make you dry-heave a tiny bit.
but this is essential what you are doing when you are "vm.*" as well.


$scope.watch(
			"app.controller.fooCount",
			function handleFooChange(newValue,oldValue){

			console.log("app.controller.fooCount:",newValue);
		}) ;



//Notice that "vm.fooCount" never watched the value we were incrementing.
This is because watching "vm.*" only works when both the controller and the view follow