Sending a promise from one controller to another in Angular - angularjs

In my web app, I would like to load all of the user data at the beginning, in the run method and pass the data to the other controllers to be shown to the user in the dashboard.
So lets say I have a data structure on the server
data = {
x : 30,
y: 20
}
I would like to get it in one http requests (instead of creating multiple http requests and creating multiple promises)
The http request I run in the run method of the app
service.getDataFromServer = function(){
return $http.get('/admin/data').then(function(response) {
data = response.data;
});
};
This will create a promise.
I would like to take this promise and pass it to other controllers to be used.
My first question is how can I do it so the data from the promise will bind to the data I am about to show to the user.
The second question is, can I use the structure fields before the promise is even resolved?
for example
$scope.x = data.x
And by data I mean the data which is about to be resolved
Thanks

I would like to get it in one http requests (instead of creating multiple http requests and creating multiple promises)
After getting response from http call,save the data in factory/services so,you can use is at another location like controller in your case by injecting it which is most recommended.
I would like to take this promise and pass it to other controllers to be used.
how can I do it so the data from the promise will bind to the data I am about to show to the user.
make http call and save the promise.
service.getDataFromServer = function() {
var promise = $http.get('test.json');
service.savePromise(promise);
}
and
get saved promise.
.controller('testCtrl', function(service) {
service.getSavedPromise().then(function(response){
console.log(response.data)
})
})
Plunker here
The second question is, can I use the structure fields before the promise is even resolved? for example
$scope.x = data.x
// data is still undefined as promise is not resolved.so,you will get TypeError
What you can do best here,you can merge data to your existing data object/array,so,Angular two way binding can do rest of the things for you.

Related

How to Execute Multiple post request simultaneously using angular js 1

I need to post same url with multiple parameters simultaneously .
how to achieve in angular 1
You do it with $http service with $http.post() request. If you want to do multiple requests, you can do it a loop. E.g. return $http.post(url,data).then((response)=>{return response.data;})
This is where you need to clarify what do you mean by saying "simultaneously", because if you want to receive the response from all of these requests at the same time, then you need something more advanced like deferred objects. This is what $q service is for, it helps you to resolve such Promises.
Firstly you need to collect all of the asynchronous callbacks in an array:
var promises = [];
angular.forEach(array, function(element) {
promises.push( $http.post(url,element).then((res)=>{return res.data}) );
}
(Pass different parameters/data however you like)
Then you need to resolve all of them at the same time with $q.all():
$q.all(promises).then((res)=>{
/* do what you need with them, e.g:
$q.defer().resolve(res)
*/
})
It should resolve an array with your data from previous requests in synch now.

Self Populating AngularJS Factories

I'm looking for some input on exactly how to accomplish the following design pattern.
Background: I have two factories and a controller:
FirstFactory: This is the data storage that contains all the data the application relies on to function
SecondFactory: This is a list of $http.get methods. The getAllCities method just returns a promise
Controller: This is where the data resolves from SecondFactory and then is set into FirstFactory.journey.
Now currently the controller works fine but I am trying to have the data, from SecondFactory.getAllCities() resolve itself in the FirstFactory on runtime instead of waiting for the Controller to update it.
So currently I have a controller that does the following:
build = function() {
return SecondFactory.getAllCities()
.then(function(response) {
FirstFactory.journey = response;
});
};
This works fine and updates the factory with a the data returned from the method SecondFactory.getAllCities(). However I feel that the controller shouldn't be what sets up the default or init data set, I think the factory should accomplish this on it's own.
I assumed, probably incorrectly, that the following would work as instead of doing the call to the SecondFactory inside the controller, I was just moving this call to the FirstFactory so it can resolve itself when its instantiated instead of relying on the controller to populate the FirstFactory.journey with data.
var build;
//This is a call to a factory that contains the data
//I want to grab and store this in my factory on run
build = function() {
SecondFactory.getAllCities()
.then(function(response) {
//Why does this not get returned?
console.log(response);
return response
})
};
//This is the factory object that is returned
return {
journey: build()
}
However the above doesn't work. The console.log in the build function contains the data I require but it isn't being returned by that function. Is this an issue with my implementation of the promise or a broader design pattern issue?

Angularjs - Can i use a controller to track when all http requests it makes are completed

I have web page interface that has three main blocks. Each block has controllers that make http requests. I want to track the calls for each block so i can unblock the interface for each block when all its calls are completed. I have a $http.interceptor that keeps count of ALL http requests and responses for the page, and can block the page until all requests have been completed, but the client doesnt like this approach.
Any suggestions.
Thanks ahead of time.
Yes, just inject and use angular's $q service and $q.all(promises), which according to the documentation
combines multiple promises into a single promise that is resolved when all of the input promises are resolved.
You can use code that looks something like this
var promiseA = $http.(......);
var promiseB = $http.(......);
var promiseC = $http.(......);
$q.all([promiseA, promiseB, promiseC]).then(function() {
//do whatever and unblock
});
one very simple way to do achieve this would be to set a "block" model on each of those individual controllers until the success of your http request. That eliminates the need for any additional controllers. Example code for inside of one of those controllers:
js
$scope.block1Loading = true;
$http
.get(url)
.success(function() {
$scope.block1Loading = false;
});
html
<div ng-controller="Block1Controller"
ng-class="{'blocked': block1Loading}">block 1</div>

Use return data from an angular service resource across all controllers with only one call

I have a custom Web API written in .NET that returns user's information that will be used in my AngularJS application. I want to be able to call my API once, and then use that returned JSON across my entire AngularJS application without having to recall the API within each of my controllers.
I currently have a factory of services, one of which returns all of the client's details I need to use the in rest of the services.
.factory('customApiService', function ($resource) {
return {
userInfo: function(userId, callback){
var api = $resource('../../api/UserInfo/:userId', {
userId: userId
}, {
fetch: 'JSONP',
'query': { isArray: false }
});
api.fetch(function (response) {
callback(response);
});
}
}
)
Now I don't want to call this userInfo service in every controller, but I do want the data to be passed into each without calling my API multiple times.
customApiService.userInfo(userId, function (d) {
var gaProfileId = d.gaProfileId;
var yelpId = d.yelpId;
var tripAdvisorId = d.tripAdvisorId;
var facebookPageName = d.facebookPage;
var twitterHandle = d.twitterHandle;
var clientName = d.clientName;
var searchlightAccountId = d.searchlightAccountId;
var searchlightDomain = d.searchlightDomainId;
}
You can try global variables .
use a $rootScope https://docs.angularjs.org/guide/scope
$rootScope is available in all controllers an templates .Just inject $rootscope in your controller or wherever required.
From what I read of your description and responses to other questions, it sounds like you're trying to make an asynchronous call before the rest of your app starts up. This is possible, but complex, and sort of voids the point of Angular in the first place. As I see it, you have two options:
QUICK HACK: If you really want this kind of behavior, why start your app at all? Do your request first, before you define your app in the first place, then define your app in the result handler for the request.
RIGHT WAY: Alter the behavior of your services and controllers to tolerate not having enough information to fully start. A lot of times this is less difficult than it sounds. Usually you can just chain a promise into their initialization block of code to wait for the data you need. Take a look at Brian Ford's "Angular Modal" project, at the lines of code I've highlighted here:
https://github.com/btford/angular-modal/blob/master/modal.js#L25-L36
This technique sets up a promise to return from the function. If the data it needs is already loaded from the service, it resolves the promise immediately. Otherwise, it makes the call to get what it's after, and you can see later (line 39) that the module uses promise.then() to wait until it has the data it needs to run.
This is a great pattern for both controllers and services when working with asynchronous data.
If using a $resource call instead, note that most $resource calls return a promise in a property called $promise. You can do something like this:
var MyController = function($scope) {
// This will get set soon!
$scope.myData = null;
var myResource = $resource('/path/to/:someId', { someId: '#id' });
myResource.get({ someId: 1 }).$promise.then(function(data) {
$scope.myData = data;
});
};
You can do more things in the .then() resolution callback for the promise, like initialize more parts of your controller, etc. There are also ways you can delay starting your entire controller until the resource is available. One really cool way is if you happen to be using the Angular ui-router module, there is a "resolve" option when defining each route. You can use that to call the $resource as shown above, and ui-router will wait to start your controller/view until it has what it needs.

AngularJS $http success but not working

i'm using angularJS and SLIM PHP restful server, the PHP service is working and actually i have already used $http.get() with no problems in this application ...
But now a strange thing is happening, i created a new function in the same way that the others, and it get .success(function(data)) with no problems, i actually can console.log(data) and it shows the right results, but when .success() finish and return, i recieve a undefined result.
ps: there is no error in browser console.
var markerOptions = [];
loadMarkers();
console.log(markerOptions);
function loadMarkers() {
$http.get('http://localhost/rest/getMarkers').success(function(response){
console.log(response);
markerOptions = response;
});
}
Console.log() inside success() return the right data
Console.log() after loadMarkers() return undefined
#MarcKline's comments are correct. Anyways, following what I think you're trying to achive by this piece of code of yours, you can assign the returned data from the ajax response to a scope variable (assuming you're using $scope), e.g $scope.markerOptions = response. You can declare markOptions as a scope variable by var $scope.markOptions = [] (...and, of course, log it by console.log($scope.markOptions) accordingly). Also, define $scope.loadMarkers = function() {...} and call it by $scope.loadMarkers()
The scope will be updated as soon as the client-side gets its ajax response.
Hope it helps your current needs in addition to a better understanding of javasciprt's async approach that some of its principles were explained to you by the comments.

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