Develop Reference

How implement background process for controller in angularjs?

Suppose there is a size several link. Every link click is handled by controller. Consider the situation:
User visit some page. Let say that it is /search where user inputs keywords and press search button.
A background process started (waitint for search response in our case)
user goes to another link
after some time user goes back to fisrt page (/search)
At the point 4 angulajs load page as user goes to it at first time. How to make angulajs remeber not state but process? E.g. if process is not finished it shows progress bar, but if it finished it give data from process result and render new page. How to implement that?
Notes
I have found this but this is about just state without process saving.
I have found that but this is about run some process at background without managing results or process state (runing or finished)

You can use angularjs service to remember this "Process" of making an api call and getting the data from it .
here is a simple implementation.
the whole idea here is to create a angular service which will make an api call,
store the data aswell as the state of the data, so that it can be accessed from other modules of angularjs. note that since angularjs services are singleton that means all of their state will be preserved.
app.service('searchService', function() {
this.searchState={
loading: false,
data: null,
error: null
}
this.fetchSearchResults = function(key){
// call api methods to get response
// can be via callbacks or promise.
this.searchState.loading=true;
someMethodThatCallsApi(key)
.then(function(success){
this.searchState.loading=false;
this.searchState.data=success;
this.searchState.error=null
})
.catch(function(error){
this.searchState.loading=false;
this.searchState.data=null;
this.searchState.error=error
});
}
this.getState = function(){
return this.searchState
}
});
// in your controller
app.controller('searchController',function(searchService){
// in your initialization function call the service method.
var searchState = searchService.getState();
// search state has your loading variables. you can easily check
// and procede with the logic.
searchState.loading // will have loading state
searchState.data // will have data
searchState.error // will have error if occured.
});
Even if you navigate from pages. the angular service will preserve the state and you can get the same data from anywhere in the application. you simply have to inject the service and call the getter method.

Based on the question, (a little bit more context or code would help answers be more targeted), when considering async operations within angularJS, its always advisable to use getters and setters within service to avoid multiple REST calls.
Please note - Services are singletons, controller is not.
for eg:
angular.module('app', [])
.controller('ctrlname', ['$scope', 'myService', function($scope, myService){
myService.updateVisitCount();
$scope.valueFromRestCall = myService.myGetterFunctionAssociated(param1, param2);
//Use $scope.valueFromRestCall to your convinience.
}]
.service('myService', ['$http', function($http){
var self = this;
self.numberOfVisits = 0;
self.cachedResponse = null;
self.updateVisitCount = function(){
self.numberOfVisits+=1;
}
self.myGetterFunctionAssociated = function(param1, param2){
if self.cachedResponse === null || self.numberOfVisits === 0 {
return $http.get(url).then(function(response){
self.cachedResponse = response;
return response;
});
}
else {
return self.cachedResponse;
}
}
return {
updateVisitCount: function(){
self.udpateVisitCount();
},
myGetterFunctionAssociated : function(param1, param2){
return self.myGetterFunctionAssociated(param1, param2);
}
}
}]

Meteor Iron router hooks being run multiple times

EDIT: Here is the github repo. And you can test the site here.
On the homepage, just open the browser console and you will notice that WaitOn and data are being run twice. When there is no WaitOn, then the data just runs once.
I have setup my pages by extending RouteController and further extending these controllers. For example:
ProfileController = RouteController.extend({
layoutTemplate: 'UserProfileLayout',
yieldTemplates: {
'navBarMain': {to: 'navBarMain'},
'userNav': {to: 'topUserNav'},
'profileNav': {to: 'sideProfileNav'}
},
// Authentication
onBeforeAction: function() {
if(_.isNull(Meteor.user())){
Router.go(Router.path('login'));
} else {
this.next();
}
}
});
ProfileVerificationsController = ProfileController.extend({
waitOn: function() {
console.log("from controller waitOn");
return Meteor.subscribe('userProfileVerification');
},
data: function() {
// If current user has verified email
console.log("from controller data start");
var verifiedEmail = Meteor.user().emails && Meteor.user().emails[0].verified ? Meteor.user().emails[0].address : '';
var verifiedPhoneNumber = Meteor.user().customVerifications.phoneNumber && Meteor.user().customVerifications.phoneNumber.verified ? Meteor.user().customVerifications.phoneNumber.number : '';
var data = {
verifiedEmail: verifiedEmail,
verifiedPhoneNumber: verifiedPhoneNumber
};
console.log("from controller data end");
return data;
}
});
On observing the console in the client, it seems the hooks are being run 2-3 times. And I also get an error on one of the times because the data is not available. The following is the console on just requesting the page once:
from controller waitOn
profileController.js?966260fd6629d154e38c4d5ad2f98af425311b71:44 from controller data start
debug.js:41 Exception from Tracker recompute function: Cannot read property 'phoneNumber' of undefined
TypeError: Cannot read property 'phoneNumber' of undefined
at ProfileController.extend.data (http://localhost:3000/lib/router/profileController.js?966260fd6629d154e38c4d5ad2f98af425311b71:46:62)
at bindData [as _data] (http://localhost:3000/packages/iron_controller.js?b02790701804563eafedb2e68c602154983ade06:226:50)
at DynamicTemplate.data (http://localhost:3000/packages/iron_dynamic-template.js?d425554c9847e4a80567f8ca55719cd6ae3f2722:219:50)
at http://localhost:3000/packages/iron_dynamic-template.js?d425554c9847e4a80567f8ca55719cd6ae3f2722:252:25
at null.<anonymous> (http://localhost:3000/packages/blaze.js?efa68f65e67544b5a05509804bf97e2c91ce75eb:2445:26)
at http://localhost:3000/packages/blaze.js?efa68f65e67544b5a05509804bf97e2c91ce75eb:1808:16
at Object.Blaze._withCurrentView (http://localhost:3000/packages/blaze.js?efa68f65e67544b5a05509804bf97e2c91ce75eb:2043:12)
at viewAutorun (http://localhost:3000/packages/blaze.js?efa68f65e67544b5a05509804bf97e2c91ce75eb:1807:18)
at Tracker.Computation._compute (http://localhost:3000/packages/tracker.js?517c8fe8ed6408951a30941e64a5383a7174bcfa:296:36)
at Tracker.Computation._recompute (http://localhost:3000/packages/tracker.js?517c8fe8ed6408951a30941e64a5383a7174bcfa:310:14)
from controller data start
from controller data end
from controller waitOn
from controller data start
from controller data end
Have I not used the controllers properly?

Without being able to see the rest of the code that you have defined that uses these route controllers (such as templates or route definitions), I cannot accurately speak to the reason for the data function being called multiple times. I suspect that you may be using the ProfileVerificationsController with multiple routes, in which case the data definition for this controller would be executed multiple times, one for each route that uses the controller. Since the data definition is reactive, as you browse through your application and data changes, this might be resulting in the code defined to be rerun.
As for your controller definitions, I would suggest making a few modifications to make the code more robust and bulletproof. First, the ProfileController definition:
ProfileController = RouteController.extend({
layoutTemplate: 'UserProfileLayout',
yieldRegions: {
'navBarMain': {to: 'navBarMain'},
'userNav': {to: 'topUserNav'},
'profileNav': {to: 'sideProfileNav'}
},
onBeforeAction: function() {
if(!Meteor.user()) {
Router.go(Router.path('login'));
this.redirect('login'); // Could do this as well
this.render('login'); // And possibly this is necessary
} else {
this.next();
}
}
});
Notice the first thing that I changed, yieldTemplates to yieldRegions. This typo would prevent the regions from your templates using this route controller to be properly filled with the desired subtemplates. Second, in the onBeforeAction definition, I would suggest checking not only whether or not the Meteor.user() object is null using Underscore, but also checking for whether or not it is undefined as well. The modification that I made will allow you to check both states of the Meteor.user() object. Finally, not so much a typo correction as an alternative suggestion for directing the user to the login route, you could use the this.redirect() and this.render() functions instead of the Router.go() function. For additional information on all available options that can be defined for a route/route controller, check this out.
Now for the ProfileVerificationsController definition:
ProfileVerificationsController = ProfileController.extend({
waitOn: function() {
return Meteor.subscribe('userProfileVerification');
},
data: function() {
if(this.ready()) {
var verifiedEmail = Meteor.user().emails && Meteor.user().emails[0].verified ? Meteor.user().emails[0].address : '';
var verifiedPhoneNumber = Meteor.user().customVerifications.phoneNumber && Meteor.user().customVerifications.phoneNumber.verified ? Meteor.user().customVerifications.phoneNumber.number : '';
var data = {
verifiedEmail: verifiedEmail,
verifiedPhoneNumber: verifiedPhoneNumber
};
return data;
}
}
});
Notice the one thing that I changed, which is to wrap all of your code defined in the data option for your controller with a if(this.ready()){}. This is critical when using the waitOn option because the waitOn option adds one or more subscription handles to a wait list for the route and the this.ready() check returns true only when all of the handles in the wait list are ready. Making sure to use this check will prevent any cases of data unexpectedly not being loaded yet when you are building up your data context for the route. For additional information on defining subscriptions for your routes/route controllers, check this out.
As a final suggestion, for your onBeforeAction option definition in your ProfileController, I would suggest moving this out into its own global hook like so:
Router.onBeforeAction(function() {
if(!Meteor.user()) {
Router.go(Router.path('login'));
} else {
this.next();
}
});
Defining this check in the global hook ensures that you don't have to worry about adding your ProfileController to all of your routes just to make sure that this check is run for all of them. The check will be run for every route every time that one is accessed. Just a suggestion, though, as you may have reasons for not doing this. I just wanted to suggest it since I make sure to do it for every Meteor app that I develop for additional security.

How to pass a function to a Meteor template?

I want to insert a Meteor template (a simple login form) but I want to control what happens after the form is submitted. Ideally, I'd like to be able to pass a function afterLogin() to the template. But I'm quite unsure how to do this and if this is even possible.
I've recently seen an interesting package viewmodel and I'm not sure how related it is. But the goal in this context is basically to render a view with a different view model.
Any ideas? I'm currently using a session variable and then after login, I check that session variable to run the correct function but this is ugly and not easy to work with. Any ideas?

This is how I do it :
I assume that your login form is called from within a parent template, use the attributes syntax to pass the value of a custom helper to the data context of the login form.
<template name="parent">
{{> loginForm options=loginFormOptions}}
</template>
The helper returns an object encapsulating a function, the caller is responsible for setting this function to whatever they want.
Template.parent.helpers({
loginFormOptions:function(){
return {
afterLogin:function(){
// we assert that the context is correct :
// this will print Template.loginForm
console.log(this.view.name);
}
};
}
});
Your login form code, acting as a library, can read from its data context the function that was passed by the caller template, and then call the function with the proper this context.
Template.loginForm.events({
"submit":function(event,template){
// ...
Meteor.loginWithPassword(...,function(error){
if(error){
console.log(error);
return;
}
// guard against the existence of the custom afterLogin function
if(template.data.options && template.data.options.afterLogin){
// execute the custom function with proper context
template.data.options.afterLogin.call(template);
}
});
}
});

First of all, I would use Iron Router for navigating through different views of my application, you can get it here:
https://github.com/EventedMind/iron-router
meteor add iron:route
Then, check http://docs.meteor.com/#template_events. I would use something like:
Template.loginFormTemplate.events({
'click .loginButton': function() {
//... if success login ...
Router.go('nextScreen');
}
});
[Update 1]
I am afraid that trying to pass function to Route is an ugly approach in a sense of Meteor architecture.
You can try though, defining some Global variable, which is responsible for listening and forward-triggering events across the Routes
var eventHelper = (function () {
var self = _.extend({
afterLogin: function () {
self.trigger('forwardedEvent');
}}, Backbone.Events);
return self;
})();
Route1.events({
'click': function () {
//... Let's call after login
eventHelper.afterLogin();
}
});
eventHelper.on('forwardedEvent',function() {
// ...
});

Ember.js: Pathless Transitional Route

New to ember.js. What I'm trying to do is: create a transitional route that has no path, that I can pass an AJAX promise to as the model when I transition to it, and then it makes a redirect decision once the promise completes. I want the LoadingRoute view to be invoked while this is happening. I've tried to accomplish that with the following route:
App.LoginUserRoute = Ember.Route.extend({
setupController: function(controller, model) {
//Model should be a promise
model.then(this.success.bind(this),this.failure.bind(this));
},
success: function (data) {
if (data.success) {
App.loggedInUser = App.User.create(data);
console.log(App.loggedInUser);
//Make redirection decision
}
else {
alert(data.error);
}
},
failure: function () {
//Failure code
}
});
However, when I try to pass the promise to the route like follows:
var request = $.post("api.php", {action: 'create_user', username: this.username, password: this.password});
this.transitionToRoute('loginUser',request);
I get the error "More context objects were passed than there are dynamic segments for the route: loginUser" because I'm trying to create a pathless route and Ember requires that the model be serialized into the path when passed using transitionToRoute().
The reason I need this is:
The login event can happen from multiple controllers (when the user registers, when they login using the login screen, or when the application first loads if the right cookie is detected) and I don't want to duplicate the login logic across all those controllers.
After the login completes, there's multiple different routes the user could then be directed to, depending on the nature of the returned user object.
I want the LoadingRoute to be invoked while the request is completing.
I assume the solution to my problem is not to use routing, but rather something else. However, I'm not sure what the "something else" would be.

You'll want to take advantage of a mixin, and hooking into the transition route.
The following SO answer will work for all of your needs:
Ember Client Side Authentication, route authentication

In the end I achieved what I was trying to do by adding the following code to ApplicationController
loginUser: function (request) {
this.transitionToRoute('loading');
request.then(this.loginRequestSuccess.bind(this),this.loginRequestFailure.bind(this));
},
loginRequestSuccess: function (data) {
if (data.success) {
App.loggedInUser = App.User.create(data.user);
console.log(App.loggedInUser);
//Route transition decision
}
else {
alert(data.error);
}
},
loginRequestFailure: function () {
//Failure code
}
And then calling the loginUser() function with the jqXHR object from wherever in the code a login request was made.

AngularJS. Best practice concerning proper two way data binding from a service

I have an 'Account' service which acts as a centralized data storage used in multiple controllers and views. This service will hold, besides getter and setter methods all data associated with two types of users, being a logged in user and an anomonous user.
The idea behind this service is that it should be used as a centralized data structure which will keep all associated views and controllers in synch. Eg: If a user logs in whe will know his email and all 'newsletter subscription' fields can be prefilled.
The current setup i use is as below. Note that each Async call on the server will return a promise.
// The Service
angular.module('A').provider('AccountService', [function() {
this.$get = function ($resource) {
var Account = {
getLoggedInAccountAsync : function () {
var Account = $resource(WebApi.Config.apiUrl + 'Account/Get');
return Account.get();
},
getUserData : function () {
return Account.userData;
},
setUserData : function (accountData) {
var merge = angular.extend((Account.currentAccountData || {}), accountData);
Account.currentAccountData = merge;
}
};
return Account;
}
});
// Our main app controller. Get's fired on every page load.
angular.module('A').controller('MainController', ['AccountService', function (AccountService) {
var loggedInAccount = AccountService.getLoggedInAccountAsync();
loggedInAccount.$then(loggedInAccountPromiseResolved);
function loggedInAccountPromiseResolved (response) {
if (response.data.isLoggedIn) {
AccountService.setAccountData(response.data);
}
};
return $scope.MainController= this;
}])
// Our specific controller. For example a newsletter subscription.
angular.module('A').controller('SpecificController', ['AccountService', function (AccountService) {
this.getUserData = AccountService.getUserData;
return $scope.Controller = this;
}])
// Newsletter subscription view
<input id="email" type="email" name="email" ng-model="SpecificController.getUserData().UserName"/>
Using the above code ensures that whenever we use the service to bind our data via Controller.getUserData().property to our view it will stay in synch throughout our entire app.
The code above will also throw if for example the .UserName value is not defined, or if there is no account data at all in case of an anomonous user. One way around this is to 'dump' our 'template' object within our service with null values this will ensure the key/values exist. Another way would be to use watchers and let our controller(s) 'write' to our service in case an user fills a field.
The first option gives me more flexability as i can centralize all the data binding in the service but it feels dirty because you never know what will happen with the server data, it could come in as a different format for example.
Does anyone have any other solution? I would prefer to not let my controllers do the writing of the data to the service.
Thank you for your time!

There are many questions here, I will answer as best as I can.
No, what you are doing is not a "best practice".
First, The model should be injected directly into the view, and maintaining the value is the responsibility of the Controller, with the help of "$scope". Your "ng-model="Controller.getUserData().UserName" is bad. There is a good example of what to do in the end of the blog article I noticed below.
Second, when you fetch data from a service, most of the time, the answer will be asynchronous, so you'd better take a look at the Promise API. The official doc of AngularJS is not always fantastic and sometimes the answer can be found on google groups or in blog article.
For your problem, here is a good article : http://markdalgleish.com/2013/06/using-promises-in-angularjs-views/

Firstly, if you use service in AngularJS, we expect a call to server or whatever that may not return data instantly. So we have two approaches of using ugly callback or beautiful $q.
I prefer using promise since it's cleaner to write. I will rewrite your snippets in a better way :
// Service
angular.module('A').provider('AccountService', [function() {
this.$get = function ($resource, $q) {
var Account = {
getUserData : function () {
var d = $q.defer();
d.resolve(Account.userData);
return d.promise;
}
};
return Account;
}
});
// Controller
angular.module('A').controller('Controller', ['AccountService', function (AccountService) {
var init = function() {
getUserData();
};
var getUserData = function() {
AccountService.getUserData().then(function(data) { $scope.username = data; });
};
init();
//return $scope.Controller = this; // you don't need to do this
}])
HTML:
<input id="email" type="email" name="email" ng-model="username"/>