CODEWITHSUNDEEP
javascriptangularjsangularjs-scope
Sanath
Sanath

Reputation: 4886

dynamically change a watch in a controller

I have the following watch in my controller.

var pageFunc = $scope.$watch('page["USER"].number', function(newob,oldob){
    console.log("WATCHING page");
    if(oldob != newob){
        //perform data load
    }
},true);

my collection looks like this

 page["USER"].number = 20;
 page["TESTER"].number = 60;
 page["BORROWER"].number = 30;
 page["CLIENT"].number = 80;

I need a single watch to watch all these collection changes for a particular element.

I have tried something like this.

       $scope.$watch('page[" '+$scope.selectedType+'"].number', function(newob,oldob)

where $scope.selectedType is set inside ng-init.

but since watch is triggered before ng-init, this fails. What is the best way to achieve this?

Upvotes: 0

Views: 32

Answers (1)

ryeballar
ryeballar

Reputation: 30098

You can watch its changes using a function callback:

$scope.$watch(function() {
  return page[$scope.selectedType].number;
}, function(newValue, oldValue) {
  if(oldValue != newValue) {
    // perform something
  }
});

Alternatively, if $scope.selectedType is a unique value, then I guess you can safely watch for it instead:

$scope.$watch('selectedType', function(newValue, oldValue) {
  if(oldValue != newValue) {
    // perform something
  }
});

Upvotes: 1

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