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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);
}
}
}]

Angular provider configuration reset when service injected into somewhere else

Not an easy one to describe this, but basically I have a service which is set up as a provider so I can configure it. It has an array of APIs used in my project which is initially empty. Various config blocks can add an API object to the array and this seems to be working. I console.log the output each time and the array is growing.
I then inject my service into something else (in this case an $http interceptor function) and use a service method to return the array, but each time I get an empty array.
I thought the way this worked is that all config blocks ran first and that the $http call which is being intercepted is happening way after that, so the array should be full of APIs by the time it's intercepted.
Anyway, here's some code
angular.module('authModule').provider('authService', function(){
var _apis = [];
return({
addApi: addApi,
$get: instantiateAuth
});
function addApi(newApi){
_apis.push(newApi);
console.log("API added", _apis);
}
function instantiateAuth() {
return({
getApis: function(){
console.log("Getting APIs", _apis);
return _apis;
}
});
}
})
.config(function($httpProvider){
$httpProvider.interceptors.push(function($log, $rootScope, $q) {
return {
request: function(config) {
var injector = angular.injector(['ng', 'authModule']);
var authService = injector.get('authService');
console.log("apis", authService.getApis());
}
};
});
});
And an example config block
angular.module('myModule').config(function ($provide, authServiceProvider) {
authServiceProvider.addApi({
url: 'https://apiurl.com',
other: 'stuff'
});
authServiceProvider.addApi({
url: 'https://apiurl2.com',
other: 'stuff'
});
});
So, each time the appApi method is called in a config block (twice here), this line outputs the array console.log("API added", _apis); and it correctly outputs 1 item after the first call and two items after the second call.
When this code - authService.getApis() - fires the first time an HTTP call is intercepted, it logs an empty array to the console.
Any help would really be appreciated.
EDIT:
The problem seems to be this line
var injector = angular.injector(['ng', 'authModule']);
My provider seems to be reset/recreated each time this happens, so maybe I'm misunderstanding how to use the injector. I was originally just injecting my authService the normal way in the function parameters but I was getting a circular dependency (my auth service needs to open a modal window, but angular-ui modals rely on the http service and my http calls are being intercepted to check with my auth service that the user is authenticated :( )

Yes, angular.injector(['ng', 'authModule']) essentially creates a new injector instance (an application instance, in layman's terms):
angular.injector(['authModule']) !== `angular.injector(['authModule'])
ng module is loaded by default, it doesn't have to be specified explicitly. And singleton services are singletons only within the same injector instance:
injector.get('authService') === injector.get('authService');
But
angular.injector(['authModule']).get('authService') !== `angular.injector(['authModule']).get('authService')
To reuse current injector instance (which is a desirable behaviour in almost every situation) $injector service should be used:
$httpProvider.interceptors.push(function($log, $rootScope, $q, $injector) {
return {
request: function(config) {
var authService = $injector.get('authService');
}
};
});
$injector.get is known and straightforward solution to get around circular dependencies.

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() {
// ...
});

Using template load as trigger for server method Meteor js

I may be using a totally incorrect approach for my problem and if so please tell me
My Meteor app collects emails address and emails them a link to a download page with a token. This download page is a Iron Router route and the token is the ID of an item in a collection. The token is checked for prior use and then a download will be initiated [that part not written yet]. So I have this route:
this.route('download', {
path: '/download/:_id',
template: 'capture_download',
waitOn: function () {
return Meteor.subscribe('captures');
},
data: function() { return Captures.findOne(this.params._id); }
});
So I need to trigger a call to my server method that does the checking logic as soon as this route is loaded. And I need the ID value to make that call. So I have this:
Template.capture_download.rendered = function(template) {
Meteor.call('claimDownload', this.data._id, function(err, result) {
// callback logic here
});
}
What I don't understand is that this only sometimes works. Sometimes the call happens with the ID value correct. Other times I get:
Exception from Deps afterFlush function function: TypeError: Cannot read property '_id' of null
So I'm thinking that either my template event [rendered] is wrong [I can't find in the docs a list of template events anywhere], or that I need to do something to wait for a valid this value, or that my approach is totally wrong. How would I fix this occasional lack of data in the view when rendered?

Use onBeforeAction within your Iron Router route, rather than a rendered method in the template:
this.route('download', {
path: '/download/:_id',
template: 'capture_download',
waitOn: function () {
return Meteor.subscribe('captures');
},
data: function() { return Captures.findOne(this.params._id); },
onBeforeAction: function() {
Meteor.call('claimDownload', this.params._id, function(err, result) {
// callback logic here
});
}
});
See https://github.com/EventedMind/iron-router/blob/dev/DOCS.md#before-and-after-hooks. Your “checking for token prior use” sounds a lot like the “checking that the user is logged in” example in the docs, which is solved with onBeforeAction.

How to reload correctly a route in Ember JS

I'm working with the latest release of Ember JS (RC1), and I have an architectural problem :
I have a very simple use case : a list of users, and a form to add users.
My Router:
App.Router.map(function () {
this.resource('users', function () {
this.route('new');
});
});
My Routes:
App.UsersRoute = Em.Route.extend({
model:function () {
return App.User.findAll();
}
});
My Controller:
App.UsersNewController = Em.ObjectController.extend({
saveUser:function () {
//'content' contains the user
App.User.save(this.content);
// here i want to reload the list of users, but it doesn't work
// The application goes correctly to the url /users
// But doesn't call the 'model' function
this.transitionToRoute('users');
}
});
As I say in the above comment, when I create a new User, I'd like to redirect to the list of users (that part works) AND reload the user list by calling the 'model' method of the route (that part doesn't).
I could write a method in UsersController to reload the list, but then I would have duplication between UsersRoute and UsersController.
Can someone help me on this problem ?
Thanks
P.S. : here a fiddle http://jsfiddle.net/vsxXj/

Ember Documentation on the model hook:
"A hook you can implement to convert the URL into the model for this
route."
So i do not think that this hook is right for this case. I think you should use the setupController hook for this case. Try this:
App.UsersRoute = Em.Route.extend({
setupController(controller){
controller.set("content", App.User.findAll());
}
});