Angular：$ scope.variable上的If-operations

Question

I want to run a function based on a $scope value. In my controller, I have:

 $scope.value = "";
 $scope.selector = function(info) { 
    if ($scope.value === "") {
       $scope.value = info;
    } else {
       $scope.value = "";
    }
 }

The function is triggered on ng-click of different images, eg:

<img ng-src="..." ng-click="selector(info)">

My problem is the if-operations dont seem to work on the $scope value. I have also tried:

 $scope.$watch('value', function(val) {
    if(val === "") {
       $scope.value = info;
    }
 }

This works if it is outside a function, but not if I place it in the selector function. Better approaches always welcome. Thanks for any explanations.

Answer 1

You need to pass the parameter from the view to the function, because your function needs an input parameter

Change the view as,

img ng-src="..." ng-click="selector(value)">

Answer 2

Try to enclose your value inside an object. There are some cases where Angular cannot "see" that the variable changed.

So, try to keep something like:

$scope.value = { value: "" };

and change the rest of the code accordingly.

I did a codepen with some fixes in your code and with what I said to you: Running example

In this example you can see the val === "" returning true and false.