Receiving a commitment from an Angular Resource

Question

Receiving a commitment from an Angular Resource

When working with $resource in Angular for CRUD operations, I'm encountering some confusion regarding the usage of different resource methods.

From what I've observed, the "regular" methods like save() and get() appear to execute synchronously. If you need asynchronous behavior, you can provide a callback function to run upon completion. Additionally, each method's result includes a $promise property that returns a promise, enabling asynchronous handling (which is my preferred approach).

However, there also exist $ versions of these methods, except for get() and query(). I am puzzled by the absence of $get() or $query() and wonder if these $ methods serve as shortcuts for .$promise.

javascript angularjs promise angular-resource

Answer 1

Answer №1

It's quite a challenge to grasp the documentation for ngResource. Essentially, you must distinguish between

class actions (methods of $resource) and
instance actions (methods of instances of $resource)

For example, class actions like

var User = $resource('/user/:userId', {userId:'@id'});
User.get({userId:123}, function(user) {
  user.abc = true;
  user.$save();
});

come with an added property $promise that is resolved upon receiving data from the $http request. This is why it can be expressed as:

User.get({userId:123})
    .$promise.then(function(user) {
      $scope.user = user;
    });

as mentioned in the docs:

Once the server responds with data, the object becomes an instance of the resource class. Actions such as save, remove, and delete are accessible as methods with the $ prefix. This simplifies performing CRUD operations (create, read, update, delete) on server-side data like so:

This explains why user.$save(); can be triggered on the instance in the aforementioned example.

Answer 2

It's quite a challenge to grasp the documentation for ngResource. Essentially, you must distinguish between

class actions (methods of $resource) and
instance actions (methods of instances of $resource)

For example, class actions like

var User = $resource('/user/:userId', {userId:'@id'});
User.get({userId:123}, function(user) {
  user.abc = true;
  user.$save();
});

come with an added property $promise that is resolved upon receiving data from the $http request. This is why it can be expressed as:

User.get({userId:123})
    .$promise.then(function(user) {
      $scope.user = user;
    });

as mentioned in the docs:

Once the server responds with data, the object becomes an instance of the resource class. Actions such as save, remove, and delete are accessible as methods with the $ prefix. This simplifies performing CRUD operations (create, read, update, delete) on server-side data like so:

This explains why user.$save(); can be triggered on the instance in the aforementioned example.

Receiving a commitment from an Angular Resource

Answer №1

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