We Keep Coding

How to store data in angularjs application?

Hi I am developing my first Angularjs application. I want to save data in Angularjs application for later use(I have used localstorage in jquery before).
For example, I will make ajax call and i will get some data, Lets say below example,
$http.post('http://192.168.0.213:1234/api/VerifyUser', $stateParams.pageList).then(function (response) {
alert(response.data);
another example, After succesfull login i will get some ID in response and i want to preserve this data all over the application. This ID i may use in all subsequent ajax calls.
I will get some data in response and i want to make use that data in other controllers as well. Is there any way i can do this? any help would be appreciated. Thank you.

you can store it in factory like below,
After your Ajax call
$http.post('http://192.168.0.213:1234/api/VerifyUser', $stateParams.pageList).then(function (response) {
alert(response.data)
SomeFactory.setData(response.data);
};
SomeFactory
(function () {
'use strict';
angular
.module('app.myApp')
.factory('SomeFactory', SomeFactory);
SomeFactory.$inject = [];
function SomeFactory() {
var someData;
var factory = {
setData: setData,
getData: getData
};
function setData(data) {
someData = data;
}
function getData() {
return someData;
}
return factory;
}
})();
In your Controllers
inject your factory to your controller and then getdata
(function () {
'use strict';
angular
.module('app.login')
.controller('LoginController', LoginController);
LoginController.$inject = ['SomeFactory'];
function LoginController(SomeFactory) {
var vm = this;
vm.someVariable = SomeFactory.getData();
console.log(vm.someVariable); // logs your data
}
})();

Sharing data between controllers can be achieved with the following options :
Factory
Service
Then you can inject the service across the controllers and use the data whenever you need.
app.service('myService', function($http) {
this.getJSON = function() {
$http.post('http://192.168.0.213:1234/api/VerifyUser', $stateParams.pageList).then(function(response) {
return response.data;
});
};
});
In Controller:
app.controller('myController', function($scope, myService) {
myService.getJSON().then(function(data) {
$scope.myData = data;
console.log(data);
});
});
DEMO

Use Service to store the data and get the data in another controller later on.
When you inject a Service, it's the same service in every controller - so you can access the properties and methods in that service all over.
https://docs.angularjs.org/guide/services
Example:
.service('YourService', function(){
var YourService = {};
YourService.yourvar = '';
return YourService;
})
.controller('controller1', function($scope, YourService){
YourService.yourvar = 'blah';
})
.controller('controller2', function($scope, YourService){
$scope.currentYourVar = YourService.yourvar;
})

How to get data from an API in a Angular Service and store it to be used by anyone in the future

This is more of a writing clean code/ optimizing existing code.
I am writing my Angular Services to fetch data from backend like this
angular.module('myApp').service('Auth', ['$http', '$q', 'Config', function($http, $q, Config) {
this.getUser = function() {
return $http.get(Config.apiurl + '/auth/user')
.then(function(response) {
return response.data;
}, function(error) {
return $q.reject(error.data);
});
};
}]);
Now in this, I am calling getUser function n number of times from the Database.
Now the question is, is it okay to call this service to get n times redundant data or I should it be saved somewhere say rootscope to be accessed later? Or storing in root scope would be bad practice and I should consider some other option or nothing at all?
Would like to get some views on Angular Community here.

Here is a sample example on how to use factory for sharing data across the application.
Lets create a factory which can be used in entire application across all controllers to store data and access them.
Advantages with factory is you can create objects in it and intialise them any where in the controllers or we can set the defult values by intialising them in the factory itself.
Factory
app.factory('SharedData',['$http','$rootScope',function($http,$rootScope){
var SharedData = {}; // create factory object...
SharedData.appName ='My App';
return SharedData;
}]);
Service
app.service('Auth', ['$http', '$q', 'SharedData', function($http, $q,SharedData) {
this.getUser = function() {
return $http.get('user.json')
.then(function(response) {
this.user = response.data;
SharedData.userData = this.user; // inject in the service and create a object in factory ob ject to store user data..
return response.data;
}, function(error) {
return $q.reject(error.data);
});
};
}]);
Controller
var app = angular.module("app", []);
app.controller("testController", ["$scope",'SharedData','Auth',
function($scope,SharedData,Auth) {
$scope.user ={};
// do a service call via service and check the shared data which is factory object ...
var user = Auth.getUser().then(function(res){
console.log(SharedData);
$scope.user = SharedData.userData;// assigning to scope.
});
}]);
In HTML
<body ng-app='app'>
<div class="media-list" ng-controller="testController">
<pre> {{user | json}}</pre>
</div>
</body>

Instead of rootScope just use a local variable of user in your service that can be accessed from anywhere in your code and so you doesn't have to call the api every time.
angular.module('metaiotAdmin').service('Auth', ['$http', '$q', 'Config', function($http, $q, Config) {
this.getUser = function() {
if(this.user){
return this.user;
}
else{
return $http.get(Config.apiurl + '/auth/user')
.then(function(response) {
this.user = response.data;
return response.data;
}, function(error) {
return $q.reject(error.data);
});
}
};
}]);
Hope it helps.

You don't have to, $http already caches your request for you, if the same request is applied in case you set the cache config option to true.
$http.get('/hello', { cache: true})
.then(onResponse)
or you can either set it for every request, by using either an interceptor or override the http instance in the $httpProvider, to apply the effect for every http request.
app.module('app.module')
factory('MyHttpInterceptor', function() {
return {
request : function(config) {
config.cache = true;
return config;
},
// rest of implementation of the interceptor
}
});
app.module('app.module')
.config(['$httpProvider', function($httpProvider) {
$httpProvider.interceptors.push('MyHttpInterceptor');
// ... rest of the configuration
}]);
Or :
app.module('app.module')
.config(['$httpProvider', function($httpProvider) {
$httpProvider.defaults.cache = true;
// ...
}]);
see :
Angular doc for caching

update variables from service when they change

I have a service to get my config settings from the db. I use this service to display various configs throughout the app. The problem I am facing is when I go to the configs page to update the configs the variables don't update until I refresh the page.
SERVICE:
app.factory('dataShare', function($rootScope, $log, $q, $http, Data) {
var configs= {};
configs.getconfigs=function(){
var deferred = $q.defer();
Data.get('config').then(function(data){
deferred.resolve(data.data);
});
return deferred.promise;
}
return configs;
});
CONTROLLER:
app.controller('authCtrl', function ($scope, $rootScope, $routeParams, $log, $location, $http, dataShare) {
dataShare.getconfigs().then(function(data){
$scope.configs = data;
});
});
HTML:
<div class="col-md-2"><span ng-if="configs[0].button_name"><a class="btn btn-sm btn-info navbar-btn" ng-href="{{configs[0].button_url}}">{{configs[0].button_name}}</a></span></div>
any help is greatly appreciated

You can put a "Watch" on the config object.
To do this , post first initialization of "config" register it to the watch service in the following manner :
$scope.config={};
$scope.$watch('config', function() {
alert('Config is updated');
//Do whatever you want to do when config gets updated
});
//Service call
You can read more about it over here https://docs.angularjs.org/api/ng/type/$rootScope.Scope
EDIT :
After going over the issue one more time , I think getting the updates on the "config" is not the issue you are facing.
If your problem is that your view is not updated even though the model is updated , you will have to use the $apply method :
dataShare.getconfigs().then(function(data){
$scope.configs = data;
$scope.$apply();
});
This would force the angular view to reflect the updated model.

Sharing data between controllers, AngularJS

I'm facing the following situation in my Angular application and I would like to have some advices here.
I have a page where I show some products, this page is managed by a controller called 'ProductsController'. This controller has a method called 'showProductDetails' which is called once the user clicks on a specific product, and the goal of this method is just to retrieve the details of the product and to display these details in a modal panel.
Nothing really special until here. The problem is that because of modularity I would like to attach a different controller to the modal panel, and to manage all the logic of this modal panel in the new controller, in this case 'ProductDetailController'. The problem is that I retrieve the data of the product before opening the modal panel, but as I retrieve this data in the scope of the first controller, from the second controller I cannot access to the product that I have previously retrieved. I've been told that to share data between controllers in angularJs is done through services, but I don't see how a stateless service can help me here.
Here is my code to understand better the situation:
The first controller:
app.controller('ProductsController', ['$scope','productsFactory','commonFactory','productsFactoryHelper','$filter','$modal',function ($scope,productsFactory,commonFactory,productsFactoryHelper,$filter,$modal)
{
$scope.showProductDetails = function (size,product) {
$scope.showLoader('Loading the details of the product. Please wait...');
productsFactoryHelper.Product.query({id:product.id},function(response)
{
$scope.selectedProduct=response;
$scope.hideLoader();
var modalInstance = $modal.open({
templateUrl: 'productDetail.html',
controller: 'ProductDetailController',
size: size
});
},function(error)
{
commonFactory.Pop('error','This product is not available at this moment. Please try again later. If the problem persists contact a system administrator');
$scope.hideLoader();
});
};
_init();
}]);
And the second controller:
app.controller('ProductDetailController',['$scope','$modalInstance', function ($scope, $modalInstance) {
$scope.ok = function () {
$modalInstance.close();
};
$scope.cancel = function () {
$modalInstance.dismiss('cancel');
};
}]);
So basically the question is how can access from the 'ProductDetailController' to the object 'selectedProduct' which is in the scope of the 'ProductsController'.
Thank you for your help.

Use resolve of the $modal to send your data to the new controller like below.
app.controller('ProductsController', ['$scope','productsFactory','commonFactory','productsFactoryHelper','$filter','$modal',function ($scope,productsFactory,commonFactory,productsFactoryHelper,$filter,$modal)
{
$scope.showProductDetails = function (size,product) {
$scope.showLoader('Loading the details of the product. Please wait...');
productsFactoryHelper.Product.query({id:product.id},function(response)
{
$scope.selectedProduct=response;
$scope.hideLoader();
var modalInstance = $modal.open({
templateUrl: 'productDetail.html',
controller: 'ProductDetailController',
size: size,
resolve:{
"selectedProduct":response
}
});
},function(error)
{
commonFactory.Pop('error','This product is not available at this moment. Please try again later. If the problem persists contact a system administrator');
$scope.hideLoader();
});
};
_init();
}]);
I dont know about the producfactory helper product query has a promise if it has a promise you can use like this..
$scope.showProductDetails = function (size,product) {
$scope.showLoader('Loading the details of the product. Please wait...');
var modalInstance = $modal.open({
templateUrl: 'productDetail.html',
controller: 'ProductDetailController',
size: size,
resolve:{
"selectedProduct":productsFactoryHelper.Product.query({id:product.id})
}
});
};
And in the ProductDetailController you can inject this selectedProduct like below
app.controller('ProductDetailController',['$scope','$modalInstance','selectedProduct ' function ($scope, $modalInstance,selectedProduct ) {
$scope.ok = function () {
$modalInstance.close();
};
$scope.cancel = function () {
$modalInstance.dismiss('cancel');
};
}]);

This can indeed be done through services, since they are stateless and keep their data once instantiated.
function productService($http) {
this.products = [];
this.loadProducts() {
$http.get('/url/to/your/product/api').then(function(err, data) {
this.products = data.products;
});
};
this.getProducts = function() {
return this.products;
}
}
angular
.module('yourModule')
.service('productService', productService);
You can then just inject productService in both controllers, load the products using productService.loadProducts(), and get them using productService.getProducts().
This is just an example. Services can be used to share any kind of data.

Services are indeed the answer for you, or you can use pure eventing if you do not need to access the data more then once.
Pure Eventing
app.controller('parentCtrl', function($scope) {
// Do something
// Action completed
#scope.$emit('someactionComplete', data);
});
app.controller('childCtrl', function($scope) {
$scope.$on('someactionComplete', function(data) {
// Process data
});
});
Using a service. The advantage of using a service is that the data is persisted.
app.controller('parentCtrl', function($scope, MyService) {
// Do something
// Action completed
MyService.setData(data);
#scope.$emit('someactionComplete');
});
app.controller('childCtrl', function($scope) {
$scope.$on('someactionComplete', function() {
MyService.getData(data);
});
});
You could further enhance this were the service loaded the data and returns a promise in the getter.

How to pass data to different controller in my case?

I am trying to create factory for the restful services.
I need to make service calls. First call's data will be used to get the second calls data.
My problem is I don't know how to transfer data from one controller to another controller.
Is there a better way to do my codes?
Here are my codes...
var app = angular.module('myApp', []);
//getting init data via service
app.factory('myService', function($http) {
var myService = {
async: function() {
var promise = $http.get('test/test.json').then(function (response) {
return response.data;
});
return promise;
}
};
return myService;
});
//retrieve data
app.controller('testCtrl', function(myService, $scope, $http) {
myService.async().then(function(data) {
$scope.data = data
//using retrieve data to get another piece of data
vay first = data[0].employee[0];
})
$http({
url: "test?" + first +'.json',
method: "GET",
}).success(function(secondData) {
$scope.secondData=secondData //How do I pass data to my secondCtrl?
})
})
app.controller('secondCtrl', function($scope) {
// I need to be able to get the secondData from testCtrl.
console.log($scope.secondData)
})
Thanks for the help!

Why don't you store the data as an object in the service itself, then both controllers depend on the service and have access to the data. Like this:
app.factory('myService', function($http) {
var that = this;
var myService = function($http) {
this.set = function(url) {
var promise = $http.get(url).then(function (response) {
that.data = promise.data;
});
return promise;
}
};
return new myService($http);
});
Then your controller sets and gets the data in the way
app.controller('testCtrl', function(myService, $scope, $http) {
myService.set('someurl').then(function() {
$scope.data = myservice.data;
//using retrieve data to get another piece of data
vay first = data[0].employee[0];
myservice.set('someOtherUrl?data='+first);
})
app.controller('secondCtrl', function($scope, myservice) {
//the data object on the myservice function has been changed on the first controller and we can reasonably expect the data we need. If these 2 controllers coexist in the same space and time we can wrap this in a $watch service
console.log(myservice.data)
});
$watch service example
app.controller('secondCtrl', function($scope, $watch, myservice) {
$watch('myservice.data', function(newval, oldval) {
console.log(newval);
}, true)
//I will only log the newvalue of myservice.data when the data has changed. the last true argument is a neccesity so that angular will compare the values within the object
});

You could either extend 'myService' to contain the response data, using it in both controllers, or you could create another service for sharing data between them.
Both solutions would look similar, but here is what the second option (new service) might look like:
Factory
.factory('SharedService', function(){
var shared = {
data: ''
}
return shared;
})
This factory could act as just a place to store some data. In fact, if all you'd like to do is share data, you could just use a value provider. But a factory you could later extend with a more complex data structure and methods.
In your controllers, just inject the service and, optionally, set it to a scope variable:
Controller 1
.controller('FirstController', function($scope, SharedService){
$scope.shared = SharedService;
$scope.shared.data = 'foo';
})
$scope.shared now references the service object. If you were to do the same in the other controller, they could both read/write to that same object:
Controller 2
.controller('SecondController', function($scope, SharedService){
$scope.shared = SharedService;
console.log($scope.shared.data); // 'foo' if called after first ctrl set it
})
Demo