I want to avoid the latency in display of initial JavaScript-rendered views. I want the user to see content immediately and have Angular take it from there. I do not want to just replace this ng-view when Angular ngRoute kicks in as a blink will likely happen. I only want it to replace it once the user hits another route.
Let's imagine this is the base route '/'. This would already exist in my HTML, rendered from the server.
<div ng-view>
<h1>Welcome. I am the first view.</h1>
<p>Please do not replace me until a user has triggered another route.</p>
</div>
I know that a common approach is to have some server-side code in an ng-view and when Angular loads it just replaces it. This is not what I'm looking to do. I want Angular to load and understand that this is actually already my first view.
Any creative ideas as to how to do this? I've looked at the source code- no luck. Maybe even a way to have Angular only replace the HTML if it is different.
Edit:
I am not looking to render templates on the server-side for use as Angular templates. I am looking to render my entire index.html on the server-side, and that would already contain everything the user needs to see for this initial base route.
6-10 seconds on any mobile is quite bad. I wouldn't blame angular here, angular is only 30kb, if that is still too slow, you've chosen wrong framework for task.
Use profiling tools to understand what is going on.
How big is the application you're dealing with?
Can you split the application into sub-applications?
Are you doing minification already for CSS & JS?
Are you lazy loading all your views & controllers?
Are you compressing everything? (gzip)
Anyways, it is possible to do pre-processing on server-side for your index.html
You can do pre-processing using nodejs, for example, and cache the pre-processed index.html.
Your nodejs pre-processor could do (pseudo-code):
function preprocessIndexHtml(queryString) {
if(cached[queryString])) return cached[queryString];
// assume angular.js is loaded
// routeConfiguration is an object that holds controller & url.
var routeConfiguration = $routeProvider.
figureOutRouteConfigurationFor(queryString);
var domTree = $(file('index.html'));
var $rootScope = $injector.get('$rootScope');
// find ng-view and clone it
var yourNgView = $($("attribute[ng-view='']").outerHTML);
// le's get rid of existing ng-view attribute
// and configure new ng-view with templateUrl & controller.
yourNgView.RemoveNgViewAttribute();
yourNgView.AddAttribute("ng-controller", routeConfiguration.controller);
yourNgView.AddAttribute("ng-view", routeConfiguration.templateUrl);
// compile the view & pass the rootScope.
$compile(yourNgView)($rootScope);
// replace the existing dom element with our compiled variant
$("attribute[ng-view='']").replaceHtmlWith(yourNgView);
// we can now cache the resulted html.
return cached[queryString] = domTree.html;
}
ngCloak
The ngCloak directive is used to prevent the Angular html template from being briefly displayed by the browser in its raw (uncompiled) form while your application is loading. Use this directive to avoid the undesirable flicker effect caused by the html template display.
https://docs.angularjs.org/api/ng/directive/ngCloak
<body ng-cloak>
You should read this article http://sc5.io/posts/how-to-implement-loaders-for-an-angularjs-app
I am not building a single-page application, but rather a "traditional" site that uses AngularJS in places. I've hit the following problem (using 1.3.0-beta.6):
Standard, working anchor links:
Link text
... [page content]
<a id="foo"></a>
<h1>Headline</h1>
[more content]
That works fine. Now I introduce a template partial somewhere:
<script type="text/ng-template" id="test-include.html">
<p>This text is in a separate partial and inlcuded via ng-include.</p>
</script>
which is invoked via:
<div ng-include="'test-include.html'"></div>
The partial is included properly, but the anchor link no longer works. Clicking on "Link text" now changes the displayed URL to /#/foo rather than /#foo and the page position does not change.
My understanding is that using ng-include implicitly tells Angular that I want to use the routes system and overrides the browser's native anchor link behavior. I've seen recommendations to work around this by changing my html anchor links to #/#foo, but I can't do that for other reasons.
I don't intend to use the routes system - I just want to use ng-include without it messing with browser behavior. Is this possible?
The reason is that angular overrides the behavior of standard HTML tags which include <a> also. I'm not sure when this change happened because angular v1.0.1 works fine with this.
You should replace the href attribute with ngClick as:
<a ng-click="scroll()">Link text</a>
And in a controller so:
function MyCtrl($scope, $location, $anchorScroll) {
$scope.scroll = function() {
$location.hash('foo');
$anchorScroll();
};
};
Demo: http://jsfiddle.net/HB7LU/3261/show/
Or simply use double hash as:
<a href='##foo'>Link text</a>
Demo: http://jsfiddle.net/HB7LU/3262/show/
Update: I did not know that you want no modification in HREF. But you can still achieve the desired result by overriding the existing a directive as:
myApp.directive('a', function() {
return {
restrict: 'E',
link: function(scope, element) {
element.attr('href', '#' + element.attr('href'));
}
};
});
Demo: http://jsfiddle.net/HB7LU/3263/
My understanding is that using ng-include implicitly tells Angular
that I want to use the routes system and overrides the browser's
native anchor link behavior. I've seen recommendations to work around
this by changing my html anchor links to #/#foo, but I can't do that
for other reasons.
Routing system is defined in a separate module ngRoute, so if you did not injected it on your own - and I am pretty sure you did not - it is not accessible at all.
The issue is somehow different here.
ng-include depends on: $http, $templateCache, $anchorScroll, $animate, $sce. So make use of ng-include initiate all these services.
The most natural candidate to investigate would be $anchorScroll. The code of $anchorScroll does not seem to do any harm, but the service depends on $window, $location, $rootScope. The line 616 of $location says:
baseHref = $browser.baseHref(), // if base[href] is undefined, it defaults to ''
So basically the base href is set to '', if it was no set before.
Now look HERE - from BalusC answer :
As to using named anchors like , with the tag
you're basically declaring all relative links relative to it,
including named anchors. None of the relative links are relative to
the current request URI anymore (as would happen without the
tag).
How to mitigate the issue?
I do not have much time today, so cannot test it myself, but what I would try to check as the first option is to hook up to '$locationChangeStart' event and if the new url is of #xxxxxx type just prevent the default behaviour and scroll with $anchorScroll native methods instead.
Update
I think this code should do the work:
$scope.$on("$locationChangeStart", function (event, next, current) {
var el, elId;
if (next.indexOf("#")>-1) {
elId = next.split("#")[1];
el = document.getElementById(elId);
if(el){
// el.scrollIntoView(); do not think we need it
window.location.hash = "#" + elId;
event.preventDefault();
}
}
});
This is the best solution, and works in recent versions of Angular:
Turn off URL manipulation in AngularJS
A lot late to the party but I found that adding a simple target="_self" fixes it.
Link
Rather than applying the angular application to the entire page, you can isolate the application to just the places you want to perform an ng-include. This will allow links outside the scope of the application to retain their normal functionality, while allowing links within the application to be handled as desired.
See this plunkr:
http://plnkr.co/edit/hOB7ixRM39YZEhaz0tfr?p=preview
The plunkr shows a link outside the app that functions as normal, and a link within the app that is handled using an overriding a directive to restore normal functionality. HTML5 mode is enabled to retain 'standard' URLs (rather than 'hashbang' [without the bang!] URLs).
You could equally run the whole of the page within the app, but I thought it would be worth demonstrating how to isolate angular to certain parts of the page in any case.
A similar question was asked here but it did not help me.
I am learning angularjs and I noticed the controller is executed twice.
I have a very simple fiddle example that shows the behavior here
I built the example as I was learning about services and at first I thought it was the injecting of the services into the controller but I commented all the code related to the services and still the controller is executed twice.
My example works but I am afraid I am doing something wrong.
<div ng-app="MyApp">
<div ng-controller="MyCtrl">
{{data1}}
</div>
</div>
var app = angular.module('MyApp', [])
app.service('Service1', function(){
return {
ajxResponse1: 'dataFromService1'
};
});
function MyCtrl($scope, Service1){
alert('Entering MyCtrl');
$scope.data1 = Service1.ajxResponse1;
alert('Exiting MyCtrl');
}
One possible source is this: if you are using Routing and specify the controller in routes - you must not specify it in template that the route uses. We had that problem when this was overlooked.
Your controller was running twice in the fiddle because angular is referenced twice (once via the Frameworks & Extensions drop down and another as an External Resource).
See this updated fiddle where I removed the External Resource and the alerts only show up once.
The code remains unchanged:
function MyCtrl($scope, Service1, Service2, Service3){
alert('Entering MyCtrl');
$scope.data1 = Service1.ajxResponse1;
$scope.data2 = Service2.ajxResponse2;
$scope.data3 = Service3.ajxResponse3;
alert('Exiting MyCtrl');
}
I had a similar problem and it was due to slashes in my routing.
I had something like /post{slug:[a-z0-9-]*/} for my route and when visiting the page at domain.com/post it would redirect to the version with a slash on the end.
Took me ages to work it out!
Edit:
Actually, just took a more detailed look at your code and noticed there is no routing in there, so this is probably not the cause in your case.
Might be useful for people like me who were looking for a different solution though.
For all the people using rails and angularjs:
The rails framework that maps URLS to views and loads them clashes with the angularjs $route even when you have a single-view application.
To prevent the double-loading of your controller:
go to application.js and remove "//= require turbolinks
You're welcome.
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.