$apply already in progress error

问题:

Stack trace:

Error: $apply already in progress
at Error (<anonymous>)
at beginPhase (file:///android_asset/www/built.min.js:7:22740)
at Object.Scope.$apply (file:///android_asset/www/built.min.js:7:25967)
at navigator.geolocation.getCurrentPosition.that (file:///android_asset/www/built.min.js:13:8670)
at Object.geolocation.getCurrentPosition (file:///android_asset/www/plugins/org.apache.cordova.core.geolocation/www/geolocation.js:122:13)
at Object.getCurrentPosition (file:///android_asset/www/built.min.js:13:8589)
at Object.getCurrentPosition (file:///android_asset/www/built.min.js:13:8277)
at Object.getCurrentCity (file:///android_asset/www/built.min.js:13:8941)
at Object.$scope.locateDevice (file:///android_asset/www/built.min.js:13:10480)
at file:///android_asset/www/built.min.js:7:12292:7

refers to this code http://pastebin.com/B9V6yvFu

    getCurrentPosition: cordovaReady(function (onSuccess, onError, options) {

        navigator.geolocation.getCurrentPosition(function () {
            var that = this,
                args = arguments;

            if (onSuccess) {
                $rootScope.$apply(function () {
                    onSuccess.apply(that, args);
                });
            }
        }, function () {
            var that = this,
                args = arguments;
            if (onError) {
                $rootScope.$apply(function () {
                    onError.apply(that, args);
                });
            }
        }, {
            enableHighAccuracy: true,
            timeout: 20000,
            maximumAge: 18000000
        });
    })

Strange thing, on my LG4X it works fine, however on my samsung s2 it throws the above error. Any ideas whats wrong?

回答1:

You are getting this error because you are calling $apply inside an existing digestion cycle.

The big question is: why are you calling $apply? You shouldn't ever need to call $apply unless you are interfacing from a non-Angular event. The existence of $apply usually means I am doing something wrong (unless, again, the $apply happens from a non-Angular event).

If $apply really is appropriate here, consider using a "safe apply" approach:

https://coderwall.com/p/ngisma

回答2:

Just use $evalAsync instead of $apply.

回答3:

You can use this statement:

if ($scope.$root.$$phase != '$apply' && $scope.$root.$$phase != '$digest') {
    $scope.$apply();
}

回答4:

If scope must be applied in some cases, then you can set a timeout so that the $apply is deferred until the next tick

setTimeout(function(){ scope.$apply(); });

or wrap your code in a $timeout(function(){ .. }); because it will automatically $apply the scope at the end of execution. If you need your function to behave synchronously, I'd do the first.

回答5:

In angular 1.3, I think, they added a new function - $scope.$applyAsync(). This function calls apply later on - they say about 10 ms later at least. It is not perfect, but it does at least eliminate the annoying error.

https://docs.angularjs.org/api/ng/type/$rootScope.Scope#$applyAsync

回答6:

In my case i use $apply with angular calendar UI to link some event:

$scope.eventClick = function(event){           
    $scope.$apply( function() {
        $location.path('/event/' + event.id);
    });
};

After reading the doc of the problem: https://docs.angularjs.org/error/$rootScope/inprog

The part Inconsistent API (Sync/Async) is very interesting:

For example, imagine a 3rd party library that has a method which will retrieve data for us. Since it may be making an asynchronous call to a server, it accepts a callback function, which will be called when the data arrives.

Since, the MyController constructor is always instantiated from within an $apply call, our handler is trying to enter a new $apply block from within one.

I change the code to :

$scope.eventClick = function(event){           
    $timeout(function() {
        $location.path('/event/' + event.id);
    }, 0);
};

Works like a charm !

Here we have used $timeout to schedule the changes to the scope in a future call stack. By providing a timeout period of 0ms, this will occur as soon as possible and $timeout will ensure that the code will be called in a single $apply block.

回答7:

At any point in time, there can be only one $digest or $apply operation in progress. This is to prevent very hard to detect bugs from entering your application. The stack trace of this error allows you to trace the origin of the currently executing $apply or $digest call, which caused the error.

More info: https://docs.angularjs.org/error/$rootScope/inprog?p0=$apply

回答8:

Just resolved this issue. Its documented here.

I was calling $rootScope.$apply twice in the same flow. All I did is wrapped the content of the service function with a setTimeout(func, 1).

回答9:

I know it's old question but if you really need use $scope.$applyAsync();

回答10:

I call $scope.$apply like this to ignored call multiple in one times.

      var callApplyTimeout = null;
      function callApply(callback) {
          if (!callback) callback = function () { };
          if (callApplyTimeout) $timeout.cancel(callApplyTimeout);

          callApplyTimeout = $timeout(function () {
              callback();
              $scope.$apply();
              var d = new Date();
              var m = d.getMilliseconds();
              console.log('$scope.$apply(); call ' + d.toString() + ' ' + m);
          }, 300);
      }

simply call

callApply();