Is it OK to fake a promise on a new angular resource? - angularjs

Question

I'm working with $resource in Angular 1.3.
I have a bunch of controllers with methods that work with the resource objects.
When the state of retrieval matters, these methods use the $promise property of the resource to ensure that they only process the objects after they are retrieved. These all work fine with existing and updated resource objects.
var ProposalResource = $resource(proposalUrl, {id: '#id'}, {'update': {method: 'PUT'}});
The resource objects are obtained by ProposalResource.get({id:....
However, when I create a new resource object in order to make a new object using new ProposalResource(..., the methods fail because the $promise property is undefined.
I've worked around this by setting the $promise property on the new resource object to a resolved promise.
This seems to work OK but it feels like a nasty kludge. The option of explicitly checking for whether or not the $promise property is defined in all the other methods is even less appealing though.
Am I doing the right thing?

Answer 1

I don't know why you need to use ProposalResource, but I usually use the $q provider.
That way you can do a simple function that returns a promise and you can call it from your controller methods.
Example service that uses a promise:
function someServiceMethod(params) {
//do something here, maybe create an object,maybe make a call with $http or something
var obj = createSomeObject(params);
//this resolves the object once the createSomeObject method or function have completed
$q.when(obj);
}
This approach is easier than doing the whole: var deferred = $q.defer(); and return deferred.promise after the deferred.resolves.
If you're using $resource, then I recommend just using $http provider from angular.
Here's $http
Here's $q

Answer 2

As mentioned in the $resource AngularJS Doucmentation:
Class actions return empty instance (with additional properties
below). Instance actions return promise of the action.
The statement above gives you a hint that instance action methods, $get, $save, ... and any other actions that you define in your $resource action definition, will always return a promise.
DEMO
e.g.
var User = $resource('user.json', {}, {
'update': {'method': 'PUT'}
});
var user = new User();
// this sends a GET request to user.json and returns the promise directly
// from the instance action.
user.$get()
.then(function(latestUserData) {
// latestUserData is also an instance of the User resource
return latestUserData.$update({
'name': 'Ryan'
});
})
.then(function(updatedUserData) {
// do whatever you want here
});
As you can see, the instance action $get returns a promise and when that promise is resolved, the .then() callback returns the response data from the server and at the same time it is wrapped/instantiated with the User $resource.