how to use $q.all for async forEach requests? - angularjs

Question

I need to call the function after 2 request is done. So I try to use $q.all for this. I have service on Angular it calls submitForm, before submit I need to do 2 another request, and after they response - make post request to submit form. It looks like this:
submitForm : function(form, params) {
var self = this;
var callback = function () {
// this is submit post req
};
angular.forEach(form, function(item) {
// I search tables (type of field) and then send req for saving tables on backend
self.uploadTables(item)
})
this.uploadFiles(params).then(callback)
}
uploadFiles : function(params) {
// this func upload files before submit
}
uploadTables : function(params) {
// for uploading tables I have another service on backend, so I need another request, before submit
}
In $q.all I guess I need to call it like $q.all(this.uploadFiles, this.uploadTables)? But I cant do that couse uploadTables I call in forEach. How can I call callback function after complete uploadFiles and uploadTables?

Answer 1

var promises = [];
angular.forEach(form, function(item) {
promises.push(self.uploadTables(item).then(uploadTableCallback));
})
promises(this.uploadFiles(params).then(uploadFilesCallback));
$q.all(promises).then(allCallback)
I want also to notice that there is nothing special in $q.all and you can always do it manually:
var promisesToResolve = arr.length;
var promisesResolve = 0;
angular.forEach(arr, function(obj) {
$http.post(obj).then(function() {
promisesResolve++;
if (promisesResolve == promisesToResolve) {
// all resolved
}
})
})

Answer 2

You can return and collect promises in array
var promises = [];
angular.forEach(form, function(item) {
var deferred = $q.defer();
//do your code
deferred.resolve(result);
promises.push(deferred.promise);
});
// execute all the promises and do something with the results
$q.all(promises).then(
function(results) {
//do your stuff
},
// error
function(response) {
}
);