Having created some basic web applications with Angular, still learning and discovering ...
I need to create a Angular application which depends on various parameters used in the application. For example various label string we will retrieve through REST... These labels are used on every screen of the application, including the first screen that is shown on start-up...
I'm looking for a 'proper' / 'good' / 'angular' way to init the application waiting for the result of a sort of 'init-application' rest-call - due to the fact that the result of this rest call contains data the application will need from start on, I have found an example approach below ...
https://blog.mariusschulz.com/2014/10/22/asynchronously-bootstrapping-angularjs-applications-with-server-side-data
Are there any more ideas / thoughts / useful links ...
Thanks!
I would suggest you to explore the 'resolve' property of ngRoute(if you are using ngRoute) or UI-router state:-
While using $routeProvider:-
$routeProvider
.when("/news", {
templateUrl: "newsView.html",
controller: "newsController",
resolve: {
message: function(messageService){
return messageService.getMessage();
}
}
})
Or, if you are using UI Router :-
$stateProvider.state('root',{
abstract:true, // this is abstract statte, controller is in child states.
templateUrl:'/assets/root-module/partial/main/main.html',
resolve : {
securityContext : function($http){
return $http.get("/security/context");
},
token : function(securityService,securityContext){
securityService.setToken(securityContext.data.token);
console.debug(securityContext.data.token);
return securityContext.data.token;
}
}
});
In either of the approaches, just make sure that you DO NOT provide 'ng-controller' in your HTML templates. Rather provide the controller while defining your route|state as the above example suggests.
The properties being "resolved" - if they are promises, the controller (hence the view) won't be initialized until the promise is resolved.
I highly recommend you to explore UI Router state hierarchy approach that allows you to share 'resolved; proerties to the child states.
Related
In a big application, i now need to access some data (json api call) from asynchronously (before, those data were accessed synchronously).
I would like not to have to change components implementation to now handle this async behaviour (too risky).
I thought about $routeProvider's "resolve" feature (with promises) that helps to abstract this async behaviour out from the components/controllers.
Unfortunately i am absolutely not using routing in any way.
Is there an implementation for that? If not, where could i start?
EDIT:
how i was before (jsonData were not loaded synchronously but it was transparent thanks to systemJS features, SystemJS, Which we are throwing in garbage now, hence the question):
https://plnkr.co/edit/BSreVYNAr7sijYwEpb5G?p=preview
How i am now:
https://plnkr.co/edit/WnX0ynOqkZsmEzIxl1SI?p=preview
Watch the console to see an example of the problems that can occur now.
I kind of made it work by going like that, but i'm not completely satisfied with it (watch the config block):
https://plnkr.co/edit/P9Rv6rnboFlaFZ0OARNG?p=preview
$provide.value('$provide', $provide);
$routeProvider.otherwise({
template: '<test></test>',
controller: function ($provide, myJsonData1) {
$provide.value('myJsonData', myJsonData1);
},
resolve: {
myJsonData1: function(){
return getMyJsonData();
}
}
});
Hope this helps :)
I'm building a web application and I have a screen that consists in five sections, each section represents a level, the areas are the higher level of my tree, when I click in any card of the area, the system should return the skills of that area and so on.
I need to change the url and state according what the user is accessing, for example, if the user access some skill, the url must be
example.com/#/curriculum/skill/<skillId>
and if I access this link it should automatically load the capabilities from this skill and his parent which is area in this case.
I have one controller for area, skill, capability, knowledge and criteria, in each controller I have a action to load the next level of the tree, which looks like that
$scope.loadSkills = function (id) {
Area.loadSkills(...)
$state.go('curriculo.skill', {id: this.current.id}, {nofity: false, reload: false});
}
And these are my states
$stateProvider
.state('curriculum', {
url: '/curriculum',
templateUrl: '/templates/curriculo.html',
})
.state('curriculum.are', {
url: '/area/:id',
template: '',
})
.state('curriculum.skill', {
url: '/skill/:id',
template: '',
})
.state('curriculum.capability', {
url: '/capability/:id',
})
.state('curriculum.knowledge', {
url: '/knowledge/:id',
})
.state('curriculum.criteria', {
url: '/criteria/:id',
});
I'm new in Angular and I not sure about what to do, should I created multiple nested views in this case, and if so, how do I load stuff that I need according the url?
I would suggest to use the capability of multiple named views offered by the ui-router. You can read more about it here. Basically the documentation says the following:
You can name your views so that you can have more than one ui-view per
template.
If you check the example in the documentation, you'll notive that there are similarities between your scenario and the example, because you want to dynamically populate a different views (here named views).
Example
I tried to recreate your scenario in this JSFiddle.
First I created an abstract state which provides the different views like areas, skills etc. This is the template for the abstract state:
<div class="curriculum" ui-view="areas"></div>
<div class="curriculum" ui-view="skills"></div>
Next I created a nested state curriculo.main, which declares the different views (areas, skills etc.) you need. Each view has its own template and controller. Notice that the nested state has a resolve which initially loads the areas from a service called curriculo. If you use resolves remember that the resolve keyword MUST be relative to the state not the views (when using multiple views).
Basically the service is responsible for the business logic, means getting the areas, skills etc. In the JSFiddle I have hard-coded the HTTP results. Replace that with HTTP calls and make use of promises. Since each named view has its own controller we need a mechanism to notify about changes, for example to notify the SkillsController that skills have been loaded. Thus, I created a simple event system (subcribe-notify):
.factory('notifier', function($rootScope) {
return {
subscribe: function(scope, callback, eventName) {
var handler = $rootScope.$on(eventName, callback);
scope.$on('$destroy', handler);
},
notify: function(eventName, data) {
$rootScope.$emit(eventName, data);
}
};
});
The SkillsController can then subscribe to a specific event like so:
notifier.subscribe($scope, function(event, data) {
$scope.skills = data;
}, 'onSkillsLoaded');
The curriculo service calls (at the end of the getSkills()) notifyand provides an event. In this case the same event as you subscribed to in the SkillsController.
notifier.notify('onSkillsLoaded', result);
All in all, that's the magic behind my little example. It's worth mentioning that you need to apply best practices to the code, since this is just to recreate your scenario. For best practices I suggest the Angular Style Guide by John Papa.
Update 1
I updated my example to show you deep linking. I simulate the deep link via
$state.go('.', {area: 2, skill: 5});
This way I can activate a certain state. Now each view has its activate function. Inside this function I do all the work that is neseccary for the initialization, e.g. selecting an area if the query param is set. As you know, you can access the params with the $state service. I had to use a $timeout to delay the init of the areas controller because the subscribe wasn't made yet. Please try to find a better solution to this problem. Maybe you can use promises or register each controller in a service which resolves if all controller have been initialized.
If anything has been selected I also use the go with an additional option to set the notify to false.
$state.go('.', {area: area.id, skill: skillId ? skillId : undefined}, {notify: false});
If notify is set to false it will prevent the controllers from being reinitialized. Thus you can only update the URL and no state change will happen.
Angular doesn't provide any authorization/access permission on routing (I'm talking default Angular route 1.x and not beta 2.0 or UI route). But I do have to implement it.
The problem I'm having is that I have a service that calls server to provide this info and returns a promise. This data however is only obtained once and then cached on the client, but it still needs to be obtained once.
I would now like to handle $routeChangeStart event that checks whether next route defines a particular property authorize: someRole. This handler should then get that data using my previously mentioned service and act accordingly to returned data.
Any ideas beside adding resolves to all my routes? Can I do this centrally somehow? Once for all routes that apply?
Final solution
With the help of accepted answer I was able to implement a rather simple and centralized solution that does async authorization. Click here to see it in action or check its inner working code.
The most simple way is to deal with current route's resolve dependencies, and $routeChangeStart is a good place to manage this. Here's an example.
app.run(function ($rootScope, $location) {
var unrestricted = ['', '/login'];
$rootScope.$on('$routeChangeStart', function (e, to) {
if (unrestricted.indexOf(to.originalPath) >= 0)
return;
to.resolve = to.resolve || {};
// can be overridden by route definition
to.resolve.auth = to.resolve.auth || 'authService';
});
$rootScope.$on('$routeChangeError', function (e, to, from, reason) {
if (reason.noAuth) {
// 'to' path and params should be passed to login as well
$location.path('/login');
}
});
});
Another option would be adding default method to $routeProvider and patching $routeProvider.when to extend route definition from default object.
ui-router have a lot of events that you can easy manipulate. I always use it.
State Change Events have everything you need. Something like this will be implement in the AngularJS 2.x.
But if you are looking the solution for native Angular 1.x.y router this solution will not help you. Sorry
If you can use ui-router, you could do this:
.state('root', {
url: '',
abstract: true,
templateUrl: 'some-template.html',
resolve: {
user: ['Auth', function (Auth) {
return Auth.resolveUser();
}]
}
})
Auth.resolveUser() is just a backend call to load the current user. It returns a promise so the route will wait for that to load before changing.
The route is abstract so other controllers must inherit from it in order to work and you have the added benefit that all child controllers have access to the current user via the resolve.
Now you catch the $stateChangeStart event in app.run():
$rootScope.$on('$stateChangeStart', function (event, next) {
if (!Auth.signedIn()) { //this operates on the already loaded user
//user not authenticated
// all controllers need authentication unless otherwise specified
if (!next.data || !next.data.anonymous) {
event.preventDefault();
$state.go('account.login');
}
}else{
//authenticated
// next.data.roles - this is a custom property on a route.
if(!Auth.hasRequiredRole(next.data.roles)){
event.preventDefault();
$state.go('account.my'); //or whatever
}
}
});
Then a route that requires a role can look like this :
.state('root.dashboard', {
//it's a child of the *root* route
url: '/dashboard',
data: {
roles: ['manager', 'admin']
}
...
});
Hope it makes sense.
I've approached this issue many times, I've also developed a module (github).
My module (built on top of ui.router) is based on $stateChangeStart (ui.router event) but the concept is the same with the default ng.route module, it's just a different implementation way.
In conclusion I think that handling routing changing events is not the good way to perform an authentication checking:
For example, when we need to obtain the acl via ajax the events can't help us.
A good way, I think, could be to automatically append a resolve to each "protected" state...
Unfortunately ui.Router doesn't provides an API to intercept the state creation so I started my module rework with a little workaround on top of $stateProvider.state method.
Definitively, I'm looking for different opinions in order to find the correct way to implement a Authentication Service in AngularJS.
if are there anyone that is interested in this research... please, open an issue on my github and the discuss
I'm building an app in which I've got a registration flow divided in 3 parts, Personal Info, Profile picture, and so on, each one in its invidual view.
So, which way do you think is the best way to persist data between views so in the final step I can show the whole data to the user and ask for confirmation.
Local Storage? $cacheFactory? I've really have no idea how to do it, any advice will be usefull!
Thanks in advance
cookie or local storage is available,but I think Angular way is recommended.
$rootScope: you can storage user data in $rootScope simply use
$rootScope.userData = {
'userName' : 'first',
'userId' : 'second'
};
to storage and read data in new view, remember to inject $rootScope into your controller
$broadcast: angular provide event $broadcast and $emit, so you can use $on to watch event and get your user data.and this is a demo http://jsfiddle.net/whitewolf/5JBA7/15/
route resolve? : if you send user data in every step to database,
you can use resolve in route config to load user data by $http.get().
add a service
app.factory("messageService", function($q){
return {
getMessage: function(){
return $q.when("Hello World!");
}};
});
in route config
$routeProvider
.when("/news", {
templateUrl: "newsView.html",
controller: "newsController",
resolve: {
message: function(messageService){
return messageService.getMessage();
}}
})
in your controller
app.controller("newsController", function (message) {
$scope.message = message;
});
You are looking for an angular wizard
if you are using ui-router, you can easily do this with nested states
have a look
http://scotch.io/tutorials/javascript/angularjs-multi-step-form-using-ui-router
one form ( main state )
separate templates (nested states)
Note: specify controller for main state only and not for nested states
It will depend on the requirement.
If there is a requirement that the user can complete two steps and
come back later to complete the third step, then better go with local
persistence.
But if it's really not the case, you need not use any persistence
mechanism. Only thing is you need to properly map the models. And on the final submit, you can persist the complete input data.
I'm building an artist portfolio web app where the artist can create a 'project' which consists of a series of content pieces (mostly images at this point) which can then be put in an order and the artist can choose between different preset layouts. I'm using angular and node + express. I'm struggling to find a good way to dynamically set templates. The only functional scheme i've devised so far is to put the template name in a query parameter in the url like this.
ui-sref="webapp/project/photo?template=vertical"
then in ui-router it's relatively simple to set the template using state params
templateUrl : function (stateparams) {
return 'templates/' + stateparams.template + '.html';
},
Although it's functional I don't like this mostly because it creates messy urls and allows anyone to change templates with query params or more likely load something without a real template because the url was typed incorrectly or correctly without the query parameter.
I can't make an api call from the templateUrl function because it's not injectable so I can't use the $http service. I've tried to use template provider but haven't made anything functional out of that yet. It does allow for an injectable function but that function must return an entire template instead of a url. If I can get a template url for it how can a load the template with that? I assume I'm not the first person to want dynamic templates (templates set in the database) from angular. What are my best options?
I have found a functional solution to my problem using ui-router, $stateParams, and $http. I'll be looking for a better architecture scheme as this necessitates 3 server requests every time a project is requested. One to get the template name and another to load the template file and another to load the project data. I suppose I only added one request to the norm. Anyways.. This solution is working for me but next I will be moving the logic to get template by the project name to an angular service to keep everything clean.
.state('projects/:project_url', {
url : '/projects/:project_url',
templateProvider : function ($stateParams, $http) {
return $http.get('/api/projects/' + $stateParams.project_url)
.then(function (data) {
// get template name
var templateName = data.data[0].template;
// return template by name
return $http.get('/pages/' + templateName + '.html')
.then(function (data) {
return data.data;
});
});
},
controller : 'projectCtrl'
});
http://dotjem.github.io/angular-routing/ supports your scenario with inject-able template functions. Note however that you must provide the raw template in the return statement, but that is easily done using the $template service...
It is very similar to UIRouter, so it should be a fairly easy transition if you find it worth it.
http://plnkr.co/edit/dkPIWMW236ixifETohNW?p=preview
If you take the latest stable release rather than the head you must add a "get" call to that service as: $template.get('template.html') rather than the newer: $template('template.html')