ui-router resolve在Ionic中表现得很奇怪 [英] ui-router resolve behaves strangely in Ionic

问题描述

我从一个演示离子应用程序开始（ ionic start myApp sidemenu ），并在其中一个视图中添加解析：

I started from a demo Ionic app (ionic start myApp sidemenu), and added a resolve to one of the views:

resolve: {
  issue: function($q, $timeout) {
    var defer = $q.defer();
    //defer.reject();       // Doesn't work browser or device
    $timeout(defer.reject); // Works in browser, but not device
    return defer.promise;
  }
}

我监控拒绝 resolve s在这里：

I monitor rejected resolves here:

.run(function($ionicPlatform, $rootScope, $ionicLoading) {
  $ionicPlatform.ready(function() {
    // regular stuff here

    $rootScope.$on('$stateChangeError', function() {
      $ionicLoading.show({
        template: 'All good!'
      });
    });
  });
});

出于某种原因，如果解决立即拒绝（参见上面的 defer.reject（）），未运行 $ stateChangeError 的回调。如果我做的完全相同，但在Ionic之外，它有效！

For some reason, if resolve rejects immediately (see defer.reject() above), the callback of $stateChangeError is not run. If I do exactly the same, but outside of Ionic, it works!

此外，尝试通过 $ timeout（defer.reject）; 解决拒绝code>导致不同的行为。现在它按预期在浏览器中工作，但仍然无法在设备上运行。试图延迟甚至更多，导致设备成功：

Moreover, trying to delay the resolve rejection by doing $timeout(defer.reject); results in a different behaviour. Now it works in a browser as expected, but still doesn't work on a device. Trying to delay even more, results in success on device:

$timeout(function() {
  defer.reject();
}, 250); // Doesn't work for me with 200 or less

任何人都可以了解这一点吗？

Can anyone shed light on this?

请看这里如何重现问题

推荐答案

根据我对Angular和promise模型的体验。为了解决/拒绝一个承诺，Angular必须勾选JS事件循环的一个循环 - nextTick - 这可以使用$ scope.apply（）完成，这就是我们在单元测试中模拟这些东西的方式。

From my experience with Angular and the promise model. In order to resolve/reject a promise Angular must tick over one cycle of the JS event loop - nextTick - and this can be accomplished using $scope.apply() which is how we mock such things in unit tests.

这是一个很棒的文章。$ evalAsync - 从我可以收集到的$ timeout是在下一个tick中评估函数。这个代码按照您概述的方式工作的原因是什么。

This is an awesome article that talks about $timeout and $scope.$evalAsync - from what I can gather $timeout is evaluating the function in the next tick. Which is the reason that this code works the way you outlined.

resolve: {
  issue: function($q, $timeout) {
    var defer = $q.defer();
    //defer.reject();       // <---- no nextTick
    $timeout(defer.reject); // <---- $timeout evaluates on nextTick
    return defer.promise;
  }
}

这是另一个文章，讨论了$ q的textTick实现。

This is another article that talks about the textTick implementation of $q.

我知道这并不能解决你的问题 - 但它应该说清楚为什么会发生这种情况！祝你好运！

I know that this doesnt solve your problem - but it should shed some light onto why this is happening! Good luck!

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