Combating AngularJS executing controller twice

问题:

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!

回答1:

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.

回答2:

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.

回答3:

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.

1. Remove redundant controller declarations
2. Check trailing slashes in routes
3. Check for ng-ifs
4. 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.)
5. 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.
6. Initializing the app twice with ng-app and with bootstrap. Combating AngularJS executing controller twice
7. 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.

回答4:

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.

回答5:

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

回答6:

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.

回答7:

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.

回答8:

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.

回答9:

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

回答10:

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!

回答11:

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.

回答12:

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\'
    }
  }
});

回答13:

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(...).

回答14:

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.

回答15:

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

回答16:

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

回答17:

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\".

回答18:

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?

回答19:

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

回答20:

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.

回答21:

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.

回答22:

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.