Passing data between controller via service won't work - javascript

I'm trying all the approaches passing data between controllers using service, factory or broadcast. None of them works for me. I follow the exact solution online, but still unfortunate. I placed service inside my app.js.
App.JS
myApp.service('customService', [function () {
this.list = [];
this.setObject = function (o) {
this.list.push(o);
},
this.getObject = function () {
return this.list;
}
}]);
Controller #1
myApp.controller('Controller1', function ($scope, customService) {
customService.setObject({..});
$window.open("/controller2", '_blank');
}
Controller #2
myApp.controller('Controller2', function ($scope, customService) {
console.log(customService.getObject()); // Returns []
}
Problem
It returns [] on controller 2 from controller 1, instead of object data.

You should modify your service for storing a object under some specific key, and then retrieve it later given that key. You can define these keys whatever you like. I defined them in the same service so I can reuse them through all controllers. Something like this
Service
myApp.service('customService', [function () {
this.keys = {"foo": "foo", "bar": "bar"};
this.list = {};
this.setObject = function (obj, key) {
this.list[ley] = obj;
},
this.getObject = function (key) {
return this.list[key];
}
}]);
Controller #1
myApp.controller('Controller1', function ($scope, customService) {
customService.setObject({"propX": "propX"}, customService.foo);
//$window.open("/controller2", '_blank');
/* I encourage you to use something like ngRoute here for navigating
* so, you should do something like $location.path('/controller2');
*/
}
Controller #2
myApp.controller('Controller2', function ($scope, customService) {
console.log(customService.getObject(customService.foo));
}

Are your controllers in the same page ?
Angular.js only works and keeps data on a single page. If your page reloads
(as you seem to indicate when you say "express.js loads the next
page", then it reinitialized everything.
You should either:
look at how to use Angular.js routing
(http://docs.angularjs.org/tutorial/step_07) so that you stay on the
same page. use something to persist your data, such as localstorage.
Find out more: http://diveintohtml5.info/storage.html
ref : Using angular service to share data between controllers

have you used routing? if u use then your code should be work.

Related

Passing variables between controllers using AngularJS

I have two controllers: Controller1 and Controller2
In Controller1's $scope, I have set up all my values I need. Using the data in $scope, I'm trying to run certain functions and pass the return values to Controller2.
I was thinking about making a factory to pass variable from Controller1 to Controller2. However, I realized all input values I need lives in Controller 1. I wonder whether factory can persist the data when it runs in Controller1 and return that data when it runs again in Controller2.
Thanks
Factory is a singleton so it can be used to share data among different controllers or directives. Take a look at the fiddler here. I have created a factory 'sharedContext' which can be used to share any key-value pair across controllers using different $scope.
Factory
myApp.factory("sharedContext", function() {
var context = [];
var addData = function(key, value) {
var data = {
key: key,
value: value
};
context.push(data);
}
var getData = function(key) {
var data = _.find(context, {
key: key
});
return data;
}
return {
addData: addData,
getData: getData
}
});
From the controller that needs to share the object can call the 'addData' method of the factory to store the data under a key. The other controllers/directives which are interested in accessing the shared data can do so by calling the 'getData' method and passing the correct key.
Controller (Sharing Data)
function MyCtrl_1($scope, sharedContext) {
$scope.input_1 = 5;
$scope.input_2 = 15;
$scope.add = function() {
$scope.result = $scope.input_1 + $scope.input_2;
sharedContext.addData("Result", $scope.result)
}
}
Controller (accessing shared data)
function MyCtrl_2($scope, sharedContext) {
$scope.getData = function() {
$scope.result = sharedContext.getData("Result").value;
}
}
The only assumption here is that both the controllers need to use the exact key to share the data. To streamline the process you can use a constant provider to share the keys. Also note that I have used underscore.js to look for the key in the shared context dictionary.
This is the simplest solution that you can come up with. As you can see the factory is a simple object and because of that construct it's passed by reference not by value that means in both controller dataFactory is the same
http://plnkr.co/edit/eB4g4SZyfcJrCQzqIieD?p=preview
var app = angular.module('plunker', []);
app.controller('ControllerOne', function (dataFactory) {
this.formFields = dataFactory
});
app.controller('ControllerTwo', function (dataFactory) {
this.formData = dataFactory
});
app.factory('dataFactory', function () {
return {};
})
edit
app.factory('dataFactory', function () {
var factory = {
method1: function (arg) {
console.log('method1: ', arg)
factory.method2('called from method1')
},
method2: function (arg) {
console.log('method2: ', arg)
}
}
return factory;
})

Angularjs share data across controllers

I use service to share data cross controllers and it works.
First page use a controller named ACtrl:
<a ng-click='doit()'>click me</a>
Second page use a different controller BCtrl:
<label>{{person.name}}</label>
In doit function, I shared an object using service. In BCtrl I get the share object ,all is fine.
But I want the second page open an another window, so I change first page as below:
<a ng-click='doit()' href='_blank'>click me</a>
Then second page doesn't work.
So how to resolve this problem?
You can send data through events, like
ACtrl
data = {a: 1, b: 2}
$rootScope.$broadcast('dataChanged', data);
BCtrl
$scope.$on('dataChanged', function(e, data) {
console.log(data);
}
Firstly define a factory service in your service.js
.factory('DataScopeService', function($rootScope) {
var mem = {};
return {
set: function(key, value) {
mem[key] = value;
},
get: function(key) {
return mem[key];
}
};
})
Then, use this service to set and get data from any controller in your project.
ControllerA
DataScopeService.set("selectedTimePeriod", '1');
ControllerB
$scope.selectedTime = DataScopeService.get("selectedTimePeriod")

Unable to sync AngularJS service with controllers (angular.copy)

I have set up two controllers (Controller A and Controller B) and a service (Service). I am attempting to sync the data from controller A to the service, and present that information to Controller B.
Within my Service, I've established a variable confirmdata and get and set functions:
function setData(data) {
confirmdata = angular.copy(data);
}
function getData() {
return confirmdata;
}
In controller A I've created a function syncto sync information from the controller to the service:
this.sync = function () {
var data = {
payment: this.getpayment()
}
Service.setData(data);
In controller B I've assigned a function as:
this.sync = function () {
this.viewData = Service.getData();
console.log('TestingData', this.viewData);
For a reason I am unaware of; my console log simply returns undefined when it should be returning the results of the getpayment() function. Am I missing something here?
The fact that you are getting undefined would indicate that you haven't initialized 'confirmdata' in your service. Whether this is the actual issue though, isn't clear. For a simple example, I would design your service like this:
myApp.factory('sharedService', [function () {
var confirmdata = {};
return {
setData: function (newData) { confirmdata = newData; },
getData: function getData() { return confirmdata; }
}
}]);
Take a look at this plunker. It gives an example of data being shared between controllers via a service.

Maintain model of scope when changing between views in AngularJS

I am learning AngularJS. Let's say I have /view1 using My1Ctrl, and /view2 using My2Ctrl; that can be navigated to using tabs where each view has its own simple, but different form.
How would I make sure that the values entered in the form of view1 are not reset, when a user leaves and then returns to view1 ?
What I mean is, how can the second visit to view1 keep the exact same state of the model as I left it ?
I took a bit of time to work out what is the best way of doing this. I also wanted to keep the state, when the user leaves the page and then presses the back button, to get back to the old page; and not just put all my data into the rootscope.
The final result is to have a service for each controller. In the controller, you just have functions and variables that you dont care about, if they are cleared.
The service for the controller is injected by dependency injection. As services are singletons, their data is not destroyed like the data in the controller.
In the service, I have a model. the model ONLY has data - no functions -. That way it can be converted back and forth from JSON to persist it. I used the html5 localstorage for persistence.
Lastly i used window.onbeforeunload and $rootScope.$broadcast('saveState'); to let all the services know that they should save their state, and $rootScope.$broadcast('restoreState') to let them know to restore their state ( used for when the user leaves the page and presses the back button to return to the page respectively).
Example service called userService for my userController :
app.factory('userService', ['$rootScope', function ($rootScope) {
var service = {
model: {
name: '',
email: ''
},
SaveState: function () {
sessionStorage.userService = angular.toJson(service.model);
},
RestoreState: function () {
service.model = angular.fromJson(sessionStorage.userService);
}
}
$rootScope.$on("savestate", service.SaveState);
$rootScope.$on("restorestate", service.RestoreState);
return service;
}]);
userController example
function userCtrl($scope, userService) {
$scope.user = userService;
}
The view then uses binding like this
<h1>{{user.model.name}}</h1>
And in the app module, within the run function i handle the broadcasting of the saveState and restoreState
$rootScope.$on("$routeChangeStart", function (event, next, current) {
if (sessionStorage.restorestate == "true") {
$rootScope.$broadcast('restorestate'); //let everything know we need to restore state
sessionStorage.restorestate = false;
}
});
//let everthing know that we need to save state now.
window.onbeforeunload = function (event) {
$rootScope.$broadcast('savestate');
};
As i mentioned this took a while to come to this point. It is a very clean way of doing it, but it is a fair bit of engineering to do something that i would suspect is a very common issue when developing in Angular.
I would love to see easier, but as clean ways to handle keeping state across controllers, including when the user leaves and returns to the page.
A bit late for an answer but just updated fiddle with some best practice
jsfiddle
var myApp = angular.module('myApp',[]);
myApp.factory('UserService', function() {
var userService = {};
userService.name = "HI Atul";
userService.ChangeName = function (value) {
userService.name = value;
};
return userService;
});
function MyCtrl($scope, UserService) {
$scope.name = UserService.name;
$scope.updatedname="";
$scope.changeName=function(data){
$scope.updateServiceName(data);
}
$scope.updateServiceName = function(name){
UserService.ChangeName(name);
$scope.name = UserService.name;
}
}
$rootScope is a big global variable, which is fine for one-off things, or small apps.
Use a service if you want to encapsulate your model and/or behavior (and possibly reuse it elsewhere). In addition to the google group post the OP mentioned, see also https://groups.google.com/d/topic/angular/eegk_lB6kVs/discussion.
Angular doesn't really provide what you are looking for out of the box. What i would do to accomplish what you're after is use the following add ons
UI Router & UI Router Extras
These two will provide you with state based routing and sticky states, you can tab between states and all information will be saved as the scope "stays alive" so to speak.
Check the documentation on both as it's pretty straight forward, ui router extras also has a good demonstration of how sticky states works.
I had the same problem, This is what I did:
I have a SPA with multiple views in the same page (without ajax), so this is the code of the module:
var app = angular.module('otisApp', ['chieffancypants.loadingBar', 'ngRoute']);
app.config(['$routeProvider', function($routeProvider){
$routeProvider.when('/:page', {
templateUrl: function(page){return page.page + '.html';},
controller:'otisCtrl'
})
.otherwise({redirectTo:'/otis'});
}]);
I have only one controller for all views, but, the problem is the same as the question, the controller always refresh data, in order to avoid this behavior I did what people suggest above and I created a service for that purpose, then pass it to the controller as follows:
app.factory('otisService', function($http){
var service = {
answers:[],
...
}
return service;
});
app.controller('otisCtrl', ['$scope', '$window', 'otisService', '$routeParams',
function($scope, $window, otisService, $routeParams){
$scope.message = "Hello from page: " + $routeParams.page;
$scope.update = function(answer){
otisService.answers.push(answers);
};
...
}]);
Now I can call the update function from any of my views, pass values and update my model, I haven't no needed to use html5 apis for persistence data (this is in my case, maybe in other cases would be necessary to use html5 apis like localstorage and other stuff).
An alternative to services is to use the value store.
In the base of my app I added this
var agentApp = angular.module('rbAgent', ['ui.router', 'rbApp.tryGoal', 'rbApp.tryGoal.service', 'ui.bootstrap']);
agentApp.value('agentMemory',
{
contextId: '',
sessionId: ''
}
);
...
And then in my controller I just reference the value store. I don't think it holds thing if the user closes the browser.
angular.module('rbAgent')
.controller('AgentGoalListController', ['agentMemory', '$scope', '$rootScope', 'config', '$state', function(agentMemory, $scope, $rootScope, config, $state){
$scope.config = config;
$scope.contextId = agentMemory.contextId;
...
Solution that will work for multiple scopes and multiple variables within those scopes
This service was based off of Anton's answer, but is more extensible and will work across multiple scopes and allows the selection of multiple scope variables in the same scope. It uses the route path to index each scope, and then the scope variable names to index one level deeper.
Create service with this code:
angular.module('restoreScope', []).factory('restoreScope', ['$rootScope', '$route', function ($rootScope, $route) {
var getOrRegisterScopeVariable = function (scope, name, defaultValue, storedScope) {
if (storedScope[name] == null) {
storedScope[name] = defaultValue;
}
scope[name] = storedScope[name];
}
var service = {
GetOrRegisterScopeVariables: function (names, defaultValues) {
var scope = $route.current.locals.$scope;
var storedBaseScope = angular.fromJson(sessionStorage.restoreScope);
if (storedBaseScope == null) {
storedBaseScope = {};
}
// stored scope is indexed by route name
var storedScope = storedBaseScope[$route.current.$$route.originalPath];
if (storedScope == null) {
storedScope = {};
}
if (typeof names === "string") {
getOrRegisterScopeVariable(scope, names, defaultValues, storedScope);
} else if (Array.isArray(names)) {
angular.forEach(names, function (name, i) {
getOrRegisterScopeVariable(scope, name, defaultValues[i], storedScope);
});
} else {
console.error("First argument to GetOrRegisterScopeVariables is not a string or array");
}
// save stored scope back off
storedBaseScope[$route.current.$$route.originalPath] = storedScope;
sessionStorage.restoreScope = angular.toJson(storedBaseScope);
},
SaveState: function () {
// get current scope
var scope = $route.current.locals.$scope;
var storedBaseScope = angular.fromJson(sessionStorage.restoreScope);
// save off scope based on registered indexes
angular.forEach(storedBaseScope[$route.current.$$route.originalPath], function (item, i) {
storedBaseScope[$route.current.$$route.originalPath][i] = scope[i];
});
sessionStorage.restoreScope = angular.toJson(storedBaseScope);
}
}
$rootScope.$on("savestate", service.SaveState);
return service;
}]);
Add this code to your run function in your app module:
$rootScope.$on('$locationChangeStart', function (event, next, current) {
$rootScope.$broadcast('savestate');
});
window.onbeforeunload = function (event) {
$rootScope.$broadcast('savestate');
};
Inject the restoreScope service into your controller (example below):
function My1Ctrl($scope, restoreScope) {
restoreScope.GetOrRegisterScopeVariables([
// scope variable name(s)
'user',
'anotherUser'
],[
// default value(s)
{ name: 'user name', email: 'user#website.com' },
{ name: 'another user name', email: 'anotherUser#website.com' }
]);
}
The above example will initialize $scope.user to the stored value, otherwise will default to the provided value and save that off. If the page is closed, refreshed, or the route is changed, the current values of all registered scope variables will be saved off, and will be restored the next time the route/page is visited.
You can use $locationChangeStart event to store the previous value in $rootScope or in a service. When you come back, just initialize all previously stored values. Here is a quick demo using $rootScope.
var app = angular.module("myApp", ["ngRoute"]);
app.controller("tab1Ctrl", function($scope, $rootScope) {
if ($rootScope.savedScopes) {
for (key in $rootScope.savedScopes) {
$scope[key] = $rootScope.savedScopes[key];
}
}
$scope.$on('$locationChangeStart', function(event, next, current) {
$rootScope.savedScopes = {
name: $scope.name,
age: $scope.age
};
});
});
app.controller("tab2Ctrl", function($scope) {
$scope.language = "English";
});
app.config(function($routeProvider) {
$routeProvider
.when("/", {
template: "<h2>Tab1 content</h2>Name: <input ng-model='name'/><br/><br/>Age: <input type='number' ng-model='age' /><h4 style='color: red'>Fill the details and click on Tab2</h4>",
controller: "tab1Ctrl"
})
.when("/tab2", {
template: "<h2>Tab2 content</h2> My language: {{language}}<h4 style='color: red'>Now go back to Tab1</h4>",
controller: "tab2Ctrl"
});
});
<!DOCTYPE html>
<html>
<script src="https://ajax.googleapis.com/ajax/libs/angularjs/1.6.9/angular.min.js"></script>
<script src="https://ajax.googleapis.com/ajax/libs/angularjs/1.6.9/angular-route.js"></script>
<body ng-app="myApp">
Tab1
Tab2
<div ng-view></div>
</body>
</html>

AngularJS - understanding scopes

I'm confused, I have this module which routes to different controllers:
var mainModule = angular.module('lpConnect', []).
config(['$routeProvider', function ($routeProvider) {
$routeProvider.
when('/home', {template:'views/home.html', controller:HomeCtrl}).
when('/admin', {template:'views/admin.html', controller:AdminCtrl}).
when('/connect', {template:'views/fb_connect.html', controller:MainAppCtrl}).
otherwise({redirectTo:'/connect'});
}]);
and a Common service like so:
mainModule.factory('Common', ['$rootScope', '$http', function (scope, http) {
var methods = {
changeLanguage:function (langID) {
http.get('JSON/langs/' + langID + '/captions.json').success(function (data) {
scope.lang = data;
});
},
initChat:function () {
console.log(scope); // full object
console.log(scope.settings); // undefined
}
};
//initiate
http.get('JSON/settings/settings.json').success(function (data) {
scope.settings = data;
methods.changeLanguage(scope.settings.lang);
});
return methods;
}]);
the app loads and gets (through XHR) the settings object, and I can see the settings reflects in my DOM. (captions for example)
Now when I call the initChat method from my HomeCtrl I get an undefined value when trying to access the scope.settings property ... what's strange is that when I log the scope I can see the settings object ... What am I missing?
Update: I found out that what I'm doing wrong is calling my method directly from the controller body:
function HomeCtrl($scope, $location, Common) {
...
Common.initChat()
...
}
if I change the call to be triggered by a click all works fine, but I do need this code to run when the page loads, What is the right approach?
It's a simple problem, I think: You're calling initChat in your scope before the $http call retrieves scope.settings.
Couple of things.
http is async and that is your main problem (as Andy astutely pointed out)
ng-init is not recommended for production code, initializing in controllers is better
initializing your scope.settings = {} or a decent default may help you, once xhr is done then your settings will be available.
hope this helps
--dan

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