Angular $routeChangeSuccess - race condition depending on controller definition? - angularjs

I'm listening to $routeChangeSuccess inside a controller:
// In MyController
$scope.$on("$routeChangeSuccess", (a, b, c) => {
console.log(a, b, c);
});
This works fine when the route changes as a result of navigation within the app, but not always when going directly to a URL in the browser e.g. /my-new-url
Performance depends on where the controller is defined:
<div ng-controller="MyController"></div>
If this is in the main index.html, it seems to work every time, however:
<mydirective ng-controller="MyController"></mydirective>
with:
app.directive('myDirective', function() {
return {
templateUrl: '<SOME_CONTENT>'
}
});
or indeed:
<mydirective></mydirective>
and :
app.directive('myDirective', function() {
return {
controller: "MyController",
templateUrl: '<SOME_CONTENT>'
}
});
These latter two only hear the $routeChangeSuccess about 50% of the time - presumably due to some compile/digest race condition.
I would much prefer to set my contoller in the directive definition - it's neater, seems nicely modular, and there's no superfluous markup. Unfortunately, it just doesn't work very often.
As a side note: why do I want to do this?
I'm struggling with an app design pattern that Angular seems to refuse to play ball with - I have a number of separate modules within my app, they're all alive at the same time, and I want them to respond to URL changes in an appropriate way.
I don't really understand why this is so hard to achieve. $routeProvider isn't of much use, because I can only have one view/controller per route - that's great if I want to build a Single Page Website, but not if I'm trying to build a Single Page Application with a complex UI. The ui-router plugin isn't really what I'm looking for either - it's more about states with optional routes.
This is the web - the URL is sacred! I want to honour it and use it as much as possible, and I want every component or module in my app to know what it's supposed to do based on the URL. I'm not sure why that's so hard with Angular.

For any component to catch an event, that component must be loaded in the memory when the even is raised.
If you have used ng-view's and controller\directives are defined as partials that load in ng-view, then it is too late for you to subscribe and listen to the event. The controller that loads when partials are loaded inside ng-view is not ready to handle the event by the time it is raised.
Anything outside the ng-view is global in nature and can always subscribe to such events.

Related

Changing how the ui-view directive handles page transitions

Edit: DON'T DO THIS. It's a waste of time unless you want to spend hours debugging, turns out this is a lot more complicated than I first thought. For now the solution to this is:
Move the loading of resources out of the resolvers and into the controller.
Remove all enter animations handled by ui-router.
Add your own animation init and enter classes to the main scope with ng-class.
Use $scope.$emit from the page-specific controllers to tell the main controller when the stuff has finished loading.
In short, if you need this (I have seen a few questions on the ui-router issue tracker) don't use resolvers or ng-animate for the enter animations. You also can't do it on the $stateChangeStart event and the leaving animations as this collides with how ui-router works.
Below is my original question.
I have a specific use case where I need the page transitions and resolves to happen in a certain order currently they happen like this:
resolve > animate out > animate in
I need it more like this:
animate out > resolve > animate in
I decided to check out the ui-router source code and find out why it behaves they way it does. Fortunately it's a very simple mod. In the ui-view directive we have this code.
scope.$on('$stateChangeSuccess', function() {
updateView(false); // cleanupLastView(); is at the end of this function
});
scope.$on('$viewContentLoading', function() {
updateView(false); // cleanupLastView(); is at the end of this function
});
I need to updated it to:
scope.$on('$stateChangeStart', function() {
cleanupLastView();
});
scope.$on('$stateChangeSuccess', function() {
updateView(false); // remove cleanupLastView();
});
scope.$on('$viewContentLoading', function() {
updateView(false); // remove cleanupLastView();
});
The problem is that for obvious reasons, I don't want to go and hack the core. Is there any way to "de-register" the ui-router's ui-view directive and tell it to use one of mine instead?
So I actually wrote this question up and then found an answer. Posting it for anyone else on their travels around the internet.
The answer was to copy BOTH ui-view directives and simply add a new directive called (for example) rich97-view. Then you can use it in your view as if you were using ui-view. The great thing about this methods is that the mod only applies where you need it to, the default behavior is unchanged.

How to communicate between controllers while not using SharedService between them?

I was reading all the answers about communication between controllers and directive, but is seems to me occurred using shared service and inject it to each one of them. When I'm developing a very large scale application, I don't know what my page is going to have in it. I may have 2 controllers need to communicate between them, and I also may have 5 directive and 2 controllers in the same page. I don't know from scratch what is going to be inside my view/page, so I need a better way how to communicate between them. I'm looking for that better way to do it, the right AngularJS way.
http://i60.tinypic.com/2z87q05.png
Above is my view example I'm working on: on the left side I have a directive tree, on the right side I have chart controller and directive grid. I may have more than this, but this is a good example of what I may have. Keep in mind, the view can have X componenets, you don't know from the beginning what will be in it.
Now, lets say each time I select node in tree on the left, I want to be able to tell the other controllers that nodeSelectedChange event happend. I don't want to inject each one of them a service that holds that info, so I thought about something like having a Page Manager Controller, which is the father of the all view. All my controllers/directives inside my page should talk with each other only by the PageManagerController, he is the only thing in page that knows what he has inside of it.
Important here to keep in mind: The tree don't know the page has chart or grid, they don't need to know each other in order to communicate. The page manager knows everything, now I want it to make the magic - Should it has a service? Should each other component has service and service can talk with PageManager service?
Help me to think. Hope I can connect all the dots to create a BETTER way for communication.
I think the sharedService way is good for small app, when you know from start what is going on in your app, but most of the time - You just don't know who and when is going to use your directive, it should be able to talk with everyone.
What I don't like about events:
The events being fired inside the controller, while it should be inside a service.
The listener controller should know the name of the event he is going to listen too. If I change the event name being $emit or $broadcast, I need to go all over the listeners $on("eventName") in all app and change to that unique name.
Directive is like a black box, I don't want to check inside of it each time and find the names of the events he is being broadcasting in order to communicate with it.
I need a way to exposed the events NAMES out of the directive, probably with a service connected to that controller.
There are a couple of good practices:
Use the $scope to communicate between directives and controllers for runtime dependencies (e.g. models you fetch from the server, instantiated classes, etc.). The way to go is to have an isolated scope with attributes mapped to the dependencies:
directive('tree', function(){
return {
scope: {
somevalue : "="
}
}
});
Use it like this:
<tree somevalue="objectFromController">
Use the injected services to communicate with static dependencies (Presentation Models, global sharable state, etc.)
directive('tree', function(treeState){
return {
scope: {
somevalue : "="
},
link: function(scope){
// some logic updating the treeState
treeState.openNodes = ['x', 'y'];
}
}
});
controller('ctrl', function($scope, treeState){
// react to treeState changes
// you can use $scope.$watch for it
// or any other way you like
// see: https://github.com/mr-mig/angular-react-to
});
If you want to have maximum composability, stick to the first pattern:
directive('tree', function(){
return {
scope: {
model : "="
},
link: function(scope){
// some logic updating the treeState, stored as scope.model
scope.model.openNodes = ['x', 'y'];
}
}
});
controller('ctrl', function($scope, treeFactory){
$scope.treeModel = treeFactory.create();
// react to treeState changes
// you can use $scope.$watch for it
// or any other way you like
// see: https://github.com/mr-mig/angular-react-to
});
And compose this stuff using template and binding as a communication bus:
<tree model="treeModel">
Sticking to this pattern you get:
No events
Well-defined directive "interface" (attributes in the isolated scope)
Easy composability
Reactive behavior based on scope change propagation
It really depends on the type of information you want to share from the tree directive to the other sections of the page.
You have a few options in front of you:
Use Scope Events
As someone mentioned above, you could fire an event and listen for events in various controllers and/or services. That said, it can get really ugly, really fast. Tracing events and figuring out what event listeners are active at a given point can give the best engineers a migraine!
Use a Service
Another option would be to use a Service, let's say a PageManagerService. In that case,
Each click of a tree item would set some information on the PageManagerService, saying which page, what objects, and what items it needs to display
Each component that needs to change could
Register a listener to be triggered when the PageManagerService changes
Add a watch on the service and run its code when the PageManagerService changes
The service itself is just going to be shared state, and it would be upto the directives and components on how it wants to consume and respond to changes in the state.
Use UI Router
But the more I think about this, the more it seems like a good use case from something like UI Router. UI Router allows you to define states, and have different parts of the page respond in different ways to state changes. Each section could respond to a state change in its own way, by loading
A different controller
A different template, possibly with different components and widgets
So what you would end up having is a structure with
The Tree directive on the left
A ui-view named, let's say, top
A ui-view named, let's say, bottom
Each item in your tree directive can then be a ui-sref, which is just a fancy way of saying instead of redirecting to a URL, redirect to a state.
You could then define your configurations in your application in a single place, like so:
$stateProvider.state('dashboard', {
views: {
"top": { templateUrl: 'my/dashboard.html', controller: 'DashboardCtrl'}
"bottom": { templateUrl: 'my/dashboard-grid.html', controller: 'DashboardGridCtrl'}
}
})
Similarly, you could have a state definition for each item in your tree directive, and each one just be a link to a different state.
Of course, the state definitions are done in your config section in an AngularJS application, which you would know is before the application starts. What if you needed dynamic states as well?
Well, a few answers / thoughts to lead you down the way for that as well:
The controllers and services would have to be predefined, you would not be dynamically creating HTML content and/or JS controllers
It is possible to expose the $stateProvider as a global variable in the config section, and dynamically call stateProvider.state inside a controller / service, wherever you have new state definitions.
More often than not though, the controllers and HTML remain constant, and we just need to trigger the different states with various parameters. That can easily be done by calling transitionTo function to transition to a defined state with various state parameters.
you can use $on, $emit and $broadcast to communicate among different controllers/scopes .
Please follow one of my earlier post . I have a setup a plunk . You can try out the example.
Angular Js newbie - link in a controller view that triggers another controller action
$on : setup a event handler
$emit : communicate to parent controllers
$broadcast : communicate to child controllers
To know more visit - https://docs.angularjs.org/api/ng/type/$rootScope.Scope

Require factory method when called by controller

I'm using an angularJS and requireJS seed which you can download here: LINK
In that seed only the controllers that are called download the relevant controller which is then triggered. I've been trying to call a factory from my controller (with no luck) plus I would like the services/factories only to download the relevant factory if it has been called.
I've attempted to require a function within the factory method (much like the controller) but it is not working.
This is where I left off: Plunkr link
user971824.
I've put together something I call couchPotato that lazy-registers just about anything in angular using requirejs and the resolution features of $routeProvider (or any other router that does lazy promise-based resolution.
I've created a plunker based on yours demonstrating how you could do it with couchPotato. If you take a look at it, I think you'll see that it's a bit simpler because you don't actually create modules for all of the things you register lazily.
couchPotato grew out of some other example apps I found on the web. What I wanted was a tight way to do the lazy registration and a provider/service combo seemed ideal. I also wanted to maintain the ability for one component to depend on another, like in your example, you want the controller to depend on the factory... couchPotato lets you specify those dependencies in requirejs syntax.
So your controller, in my rendition, looks like this:
define(['app', 'myFactory'], function(app) {
app.couchPotato.registerController([
'mycontroller',
[
'myFactory',
function(myFactory) {
var message = myFactory.getCustomers();
alert(message);
}
]
]);
});
In this example, I made the controller, the factory and the value all lazy, but you could pick and choose and have some registered the "old fashioned way" at configuration time and others registered with couchPotato when they're needed for a given route.
http://plnkr.co/edit/Z3v1mszQiiq024po8Ocp?p=preview
A couple of things to note:
1) I put in a default route in order to trigger the lazy loading of your controller, your service (factory) and the version value.
2) I modified your service to append the version just to show how one component can depend on another (the service depends on the version value, the controller depends on the service).
So, within the require configuration, you don't actually specify any of this... it's all done lazily within your route.
$routeProvider.when('/',
$couchPotatoProvider.resolveDependenciesProperty({
templateUrl:'home.html',
controller: 'mycontroller',
dependencies: [
'mycontroller'
]
})
);
Since mycontroller depends on myFactory and myFactory depends on version, by the time your route is displayed they are all available and hooked up. I put some dummy text in the home.html partial just for kicks, but the controller is assigned by the $routeProvider so you don't actually need to specify it in the template.
couchPotato lives at https://github.com/afterglowtech/angular-couchPotato if you'd like to see a couple of other samples. I shim'ed it in dependent on angular because I designed it to be usable in cases where an entire application doesn't necessarily use requirejs... thus if you are loading angular with requirejs, you need to make couchPotato dependent on angular using the shim/deps technique.
LMK if you have any questions/comments... hope this helps!

How to run code on a route that has access to services

I wonder what's the best way to configure a route which only purpose is to make use of a service call and then redirect.
I'm currently using this hack:
$routeProvider.when('/talks', {
template: '<div></div>',
controller: ['dateService', '$location', function(dateService, $location){
var nextTalk = dateService.getNextTalkDate();
$location.path('talks/' + nextTalk.format('MM') + '/' + nextTalk.format('YYYY'));
}]
});
Currently I set the controller configuration to an inline controller implementation which has dependencies on the services and then does it's thing and redirects.
However, it feels a bit weird, since I have to set template to some dummy value because otherwise the controller would not be invoked at all.
It feels as if I'm stressing the controller property for something it wasn't intended for.
I guess there should be a way to run some view unrelated code that has access to services on a route. I could right my own $routeProvider I guess but that seems to be a bit heavy for something I would consider should be built in.
Looks like '/talks' is a kinda abstract since its just used to redirect to other routes.. So how about setting up a route like this:
''/talks/:month/:year'
Where :month and :year is optional. If no month or year is given, your service returns a default talk. Which is probably the next talk. If params are given you just fetch the requested data.
So there's no redirect required. Now you specifiy the controller and the needed view and expose your data on the scope. Optionally would it be better to wrap your service call in a promise and resolve it at routeProviders resolve property.
This makes sure that the view only change if everything's resolved fine.
Hope that helps!
There's no way to inject services into anywhere into a route. Whether it be redirectTo or template, any code in there is handled on the module level. This means that the module is loaded first and then when the application has boostrapped itself then the services and injection-level code is executed. So the controller is your best bet (since that does support injection).
Controller is used in a lot of areas in AngularJS and it should work fine for what you're trying to do. You can either handle the redirection like you do in there or you can setup three different routes that point to the same controller (where you build the page).
var handler = { controller : 'Ctrl' };
$routeProvider.when('/talks', handler).
when('/talks/:month, handler).
when('/talks/:month/:year', handler);
And if you do end up using redirection, then just use $location.path(url).replace(). This will make the history stack jump back one level and therefore that the redirection triggering URL won't be in your history.

Combating AngularJS executing controller twice

I understand AngularJS runs through some code twice, sometimes even more, like $watch events, constantly checking model states etc.
However my code:
function MyController($scope, User, local) {
var $scope.User = local.get(); // Get locally save user data
User.get({ id: $scope.User._id.$oid }, function(user) {
$scope.User = new User(user);
local.save($scope.User);
});
//...
Is executed twice, inserting 2 records into my DB. I'm clearly still learning as I've been banging my head against this for ages!
The app router specified navigation to MyController like so:
$routeProvider.when('/',
{ templateUrl: 'pages/home.html',
controller: MyController });
But I also had this in home.html:
<div data-ng-controller="MyController">
This digested the controller twice. Removing the data-ng-controller attribute from the HTML resolved the issue. Alternatively, the controller: property could have been removed from the routing directive.
This problem also appears when using tabbed navigation. For example, app.js might contain:
.state('tab.reports', {
url: '/reports',
views: {
'tab-reports': {
templateUrl: 'templates/tab-reports.html',
controller: 'ReportsCtrl'
}
}
})
The corresponding reports tab HTML might resemble:
<ion-view view-title="Reports">
<ion-content ng-controller="ReportsCtrl">
This will also result in running the controller twice.
AngularJS docs - ngController
Note that you can also attach controllers to the DOM by declaring it
in a route definition via the $route service. A common mistake is to
declare the controller again using ng-controller in the template
itself. This will cause the controller to be attached and executed
twice.
When you use ngRoute with the ng-view directive, the controller gets attached to that dom element by default (or ui-view if you use ui-router). So you will not need to attach it again in the template.
I just went through this, but the issue was different from the accepted answer. I'm really leaving this here for my future self, to include the steps I went through to fix it.
Remove redundant controller declarations
Check trailing slashes in routes
Check for ng-ifs
Check for any unnecessary wrapping ng-view calls (I accidentally had left in an ng-view that was wrapping my actual ng-view. This resulted in three calls to my controllers.)
If you are on Rails, you should remove the turbolinks gem from your application.js file. I wasted a whole day to discover that. Found answer here.
Initializing the app twice with ng-app and with bootstrap. Combating AngularJS executing controller twice
When using $compile on whole element in 'link'-function of directive that also has its own controller defined and uses callbacks of this controller in template via ng-click etc. Found answer here.
Just want to add one more case when controller can init twice (this is actual for angular.js 1.3.1):
<div ng-if="loading">Loading...</div>
<div ng-if="!loading">
<div ng-view></div>
</div>
In this case $route.current will be already set when ng-view will init. That cause double initialization.
To fix it just change ng-if to ng-show/ng-hide and all will work well.
Would like to add for reference:
Double controller code execution can also be caused by referencing the controller in a directive that also runs on the page.
e.g.
return {
restrict: 'A',
controller: 'myController',
link: function ($scope) { ....
When you also have ng-controller="myController" in your HTML
When using angular-ui-router with Angular 1.3+, there was an issue about Rendering views twice on route transition. This resulted in executing controllers twice, too. None of the proposed solutions worked for me.
However, updating angular-ui-router from 0.2.11 to 0.2.13 solved problem for me.
I tore my app and all its dependencies to bits over this issue (details here: AngularJS app initiating twice (tried the usual solutions..))
And in the end, it was all Batarang Chrome plugin's fault.
Resolution in this answer:
I'd strongly recommend the first thing on anyone's list is to disable it per the post before altering code.
If you know your controller is unintentionally executing more than once, try a search through your files for the name of the offending controller, ex: search: MyController through all files. Likely it got copy-pasted in some other html/js file and you forgot to change it when you got to developing or using those partials/controllers. Source: I made this mistake
I had the same problem, in a simple app (with no routing and a simple ng-controller reference) and my controller's constructor did run twice. Finally, I found out that my problem was the following declaration to auto-bootstrap my AngularJS application in my Razor view
<html ng-app="mTest1">
I have also manually bootstrapped it using angular.bootstrap i.e.
angular.bootstrap(document, [this.app.name]);
so removing one of them, it worked for me.
In some cases your directive runs twice when you simply not correct close you directive like this:
<my-directive>Some content<my-directive>
This will run your directive twice.
Also there is another often case when your directive runs twice:
make sure you are not including your directive in your index.html TWICE!
Been scratching my head over this problem with AngularJS 1.4 rc build, then realised none of the above answers was applicable since it was originated from the new router library for Angular 1.4 and Angular 2 at the time of this writing. Therefore, I am dropping a note here for anyone who might be using the new Angular route library.
Basically if a html page contains a ng-viewport directive for loading parts of your app, by clicking on a hyperlink specified in with ng-link would cause the target controller of the associated component to be loaded twice. The subtle difference is that, if the browser has already loaded the target controller, by re-clicking the same hyperlink would only invoke the controller once.
Haven't found a viable workaround yet, though I believe this behaviour is consistent with the observation raised by shaunxu, and hopefully this issue would be resolved in the future build of new route library and along with AngularJS 1.4 releases.
In my case, I found two views using the same controller.
$stateProvider.state('app', {
url: '',
views: {
"viewOne#app": {
controller: 'CtrlOne as CtrlOne',
templateUrl: 'main/one.tpl.html'
},
"viewTwo#app": {
controller: 'CtrlOne as CtrlOne',
templateUrl: 'main/two.tpl.html'
}
}
});
The problem I am encountering might be tangential, but since googling brought me to this question, this might be appropriate. The problem rears its ugly head for me when using UI Router, but only when I attempt to refresh the page with the browser refresh button. The app uses UI Router with a parent abstract state, and then child states off the parent. On the app run() function, there is a $state.go('...child-state...') command. The parent state uses a resolve, and at first I thought perhaps a child controller is executing twice.
Everything is fine before the URL has had the hash appended.
www.someoldwebaddress.org
Then once the url has been modified by UI Router,
www.someoldwebaddress.org#/childstate
...and then when I refresh the page with the browser refresh button, the $stateChangeStart fires twice, and each time points to the childstate.
The resolve on the parent state is what is firing twice.
Perhaps this is a kludge; regardless, this does appear to eliminate the problem for me: in the area of code where $stateProvider is first invoked, first check to see if the window.location.hash is an empty string. If it is, all is good; if it is not, then set the window.location.hash to an empty string. Then it seems the $state only tries to go somewhere once rather than twice.
Also, if you do not want to rely on the app's default run and state.go(...), you can try to capture the hash value and use the hash value to determine the child state you were on just before page refresh, and add a condition to the area in your code where you set the state.go(...).
For those using the ControllerAs syntax, just declare the controller label in the $routeprovider as follows:
$routeprovider
.when('/link', {
templateUrl: 'templateUrl',
controller: 'UploadsController as ctrl'
})
or
$routeprovider
.when('/link', {
templateUrl: 'templateUrl',
controller: 'UploadsController'
controllerAs: 'ctrl'
})
After declaring the $routeprovider, do not supply the controller as in the view. Instead use the label in the view.
In my case it was because of the url pattern I used
my url was like /ui/project/:parameter1/:parameter2.
I didn't need paramerter2 in all cases of state change. In cases where I didn't need the second parameter my url would be like /ui/project/:parameter1/. And so whenever I had a state change I will have my controller refreshed twice.
The solution was to set parameter2 as empty string and do the state change.
I've had this double initialisation happen for a different reason. For some route-transitions in my application I wanted to force scrolling to near the top of the page (e.g. in paginated search results... clicking next should take you to the top of page 2).
I did this by adding a listener to the $rootScope $on $viewContentLoaded which (based on certain conditions) executed
$location.hash('top');
Inadvertently this was causing my routes to be reevaluated and the controllers to be reinitialised
My issue was updating the search parameters like so $location.search('param', key);
you can read more about it here
controller getting called twice due to append params in url
In my case renaming the controller to a different name solved the problem.
There was a conflict of controller names with "angular-ui-tree" module: I renamed my controller from "CatalogerTreeController" to "TreeController" and then this controller starts to be initiated twice on the page where "ui-tree" directive used because this directive uses controller named "TreeController".
I had the same problem and after trying all the answers I finally found that i had a directive in my view that was bound to the same controller.
APP.directive('MyDirective', function() {
return {
restrict: 'AE',
scope: {},
templateUrl: '../views/quiz.html',
controller: 'ShowClassController'
}
});
After removing the directive the controller stopped being called twice. Now my question is, how can use this directive bound to the controller scope without this problem?
I just solved mine, which was actually quite disappointing. Its a ionic hybrid app, I've used ui-router v0.2.13. In my case there is a epub reader (using epub.js) which was continuously reporting "no document found" once I navigate to my books library and select any other book. When I reloaded the browser book was being rendered perfectly but when I selected another book got the same problem again.
My solve was very simple. I just removed reload:true from $state.go("app.reader", { fileName: fn, reload: true }); in my LibraryController
I have the same issue in angular-route#1.6.7, and it because the extra slash in the end of regex route:
.when('/goods/publish/:classId/', option)
to
.when('/goods/publish/:classId', option)
and it works correctly.
Just adding my case here as well:
I was using angular-ui-router with $state.go('new_state', {foo: "foo#bar"})
Once I added encodeURIComponent to the parameter, the problem was gone: $state.go('new_state', {foo: encodeURIComponent("foo#bar")}).
What happened?
The character "#" in the parameter value is not allowed in URLs. As a consequence, angular-ui-router created my controller twice: during first creation it passed the original "foo#bar", during second creation it would pass the encoded version "foo%40bar". Once I explicitly encoded the parameter as shown above, the problem went away.
My issue was really difficult to track down. In the end, the problem was occurring when the web page had missing images. The src was missing a Url. This was happening on an MVC 5 Web Controller. To fix the issue, I included transparent images when no real image is available.
<img alt="" class="logo" src="">
I figured out mine is getting called twice is because i was calling the method twice from my html.
`<form class="form-horizontal" name="x" ng-submit="findX() novalidate >
<input type="text"....>
<input type="text"....>
<input type="text"....>
<button type="submit" class="btn btn-sm btn-primary" ng-click="findX()"
</form>`
The highlighted section was causing findX() to be called twice. Hope it helps someone.

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