How do I return data from a $http.get() inside a factory in angularjs

Question

I\'m having a lot of trouble with this and I can\'t seem to find anything here on SO or Google that helps me spot what I\'m doing wrong

Answer 1

What's happening here is a result of the asynchronous nature of $http.get, When you run $http.get it doesn't run in order. That is, it 'branches off' and runs along side the rest of the code. This is done to accommodate for the server latency.

Here's a bad visualisation.

.getResponse Called                Return Temp.
|-------------------|--------------|
                    |---------------------------------|
                    $http.get ~Waiting for Server~    Temp assigned to data.

Can you see how Temp is returned before it's been given a value?

Thankfully, you can use what Angular calls a promise, This is a variable which you can return from a function, that gets 'resolved' later. You instantiate a promise like this.

var myPromise = $q.defer();

You assign values to it by using

myPromise.resolve(data);

You can then return this promise later in the function, in the normal way. ie.

return myPromise.promise

Of course, for all of this you need the $q library, which you include in the function parameters.