使用AngularJS进行多服务http调用

Question

In my controller I am calling a service with the following code:

Service.updateData(data).then(function (result) {
  console.log(result);
});

In my service I am using $q to get multiple HTTP requests.

$rootScope.http_1 = $http.get();
$rootScope.http_2 = $http.get();

$q.all([$rootScope.http_1, $rootScope.http_2]).then(function(result) {
    console.log(result[0], result[1]);
    return result[0], result[1];
});

The code actually works as the http requests are successfully made. However, I get an error in the controller which says: TypeError: Cannot read property 'then' of undefined. I believe this is due the service not returning the promise in the correct way. Any ideas on how to resolve this would be much appreciated?

Answer 1

It looks like you are not returning the promise in updateData Try this:

updateData = function(data) {
    $rootScope.http_1 = $http.get();
    $rootScope.http_2 = $http.get();

    return $q.all([$rootScope.http_1, $rootScope.http_2]);
}

1. You didn't return the promise, so there is nothing to call .then() on in your controller
2. You are returning inside the .then() function inside your service.updateData() , which doesn't do very much for you.

If you want to control it all inside the service and return a specific format, try this:

updateData = function(data) {
    $rootScope.http_1 = $http.get();
    $rootScope.http_2 = $http.get();
    var defer = $q.defer();
    $q.all([$rootScope.http_1, $rootScope.http_2]).then(function(result){
       // process here to get the data how you want it, say in some new var foo
       var foo = "some processed data based on result";
       defer.resolve(foo);
    });
    return defer.promise;
}