Connect an Angular Service object to a Controller's Scope and keeping it in sync

Question

Connect an Angular Service object to a Controller's Scope and keeping it in sync

I am facing an issue with the interaction between my EmployeeService and EmployeeController. The service contains a specific object which I bind to the controller's scope:

app.controller('EmployeeController', function($scope, EmployeeService) {
    $scope.employee = EmployeeService.getEmployee();
}

Within the HTML template, I display the name of the employee like this:

{{employee.name}}

When I make changes to the employee object in the EmployeeService, such as updating the name, the template reflects the new name. However, if I completely replace the employee object using

EmployeeService.setEmployee({name: 'new name'})

, the template does not update accordingly.

This discrepancy is demonstrated in my Plunk here: http://plnkr.co/edit/k7oKd1VgsBvMGvVdP5kM?p=preview

In the provided Plunk, the functionality works for Employee Controller/Service but not for Manager Controller/Service. Any insights or help on this matter would be greatly appreciated.

javascript angularjs angularjs-scope

Answer 1

Answer №1

Ensure the controller is able to monitor any changes in the manager.

$scope.$watch(function() {
    return ManagerService.getManager();//<--when this changes
  }, function(newManager) { //<-- execute this function
    $scope.manager = ManagerService.getManager();
  });

Check out this updated Plunkr for one method of accomplishing this: http://plnkr.co/edit/YE72JcxDSFqfZLH32ERy?p=preview

Answer 2

Ensure the controller is able to monitor any changes in the manager.

$scope.$watch(function() {
    return ManagerService.getManager();//<--when this changes
  }, function(newManager) { //<-- execute this function
    $scope.manager = ManagerService.getManager();
  });

Check out this updated Plunkr for one method of accomplishing this: http://plnkr.co/edit/YE72JcxDSFqfZLH32ERy?p=preview

Answer 3

Answer №2

The reason for this behavior lies in how angular keeps track of the original object. When you use {{employee.name}}, angular monitors changes to the reference of the object. As noted by you: modifications to

EmployeeService.getEmployee().name

are detected and displayed in the view.

However, when you call

EmployeeService.setEmployee({name: 'new name'})

, angular replaces the observed object with a new one while still keeping an eye on the old one. This results in your alteration going unnoticed by angular, leading to no update in the view.

Answer 4

The reason for this behavior lies in how angular keeps track of the original object. When you use {{employee.name}}, angular monitors changes to the reference of the object. As noted by you: modifications to

EmployeeService.getEmployee().name

are detected and displayed in the view.

However, when you call

EmployeeService.setEmployee({name: 'new name'})

, angular replaces the observed object with a new one while still keeping an eye on the old one. This results in your alteration going unnoticed by angular, leading to no update in the view.

Connect an Angular Service object to a Controller's Scope and keeping it in sync

Answer №1

Answer №2

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