在页面重新加载Firebase中处理异步验证以获取需要用户的uid的列表 [英] Handle asynchronous authentication in Firebase on page reload to get list that needs user's uid

问题描述

使用Angularjs。如何处理人员重新加载页面的情况，并且在触发Firebase身份验证事件之前，控制器尝试使用当前用户的uid查询Firebase并有机会设置当前用户？

详细信息：
Firebase查询需要的是用户的uid，当通过$ state.go（'/ list'）导航到路由时，所有内容都可以正常工作。

但是，当一个人重新加载页面时，控制器会检查用户，直到事件处理程序触发为止：

  auth.onAuthStateChanged（function（user）{
 if（user）{
 //设置用户
 UserSrvc.currentUser = user; 
} else {
 $ state .go（'/ login'）; 
} 
}）; 
 
 
 $ b app.controller（'ListCtrl'，function（$ scope，UserSrvc，Posts）{
 
 if（！UserSrvc.currentUser）{ 
 UserSrvc.getUser（）; 
}; 
 
 $ scope.posts = Posts.list（）;<  - 这个生成错误，因为没有用户是$ b $如果Firebase仍然具有同步认证调用，那么这不会是一个问题，因为我可以
 
 
所以：
 
 
 
 
  > 
 
如果用户没有登录，UserSrvc.getUser（）如何导航到$ state.go（'/ login'）而没有Posts.list（）执行？
 
 
 
 
解决方案
将帖子加载到 onAuthStateChanged（）： 
 
 
  app.controller 'ListCtrl'，函数（$ scope，UserSrvc，Posts）{
 auth.onAuthStateC （用户）{$超时（函数（）{
如果（用户）{
 UserSrvc.currentUser = user; 
 if（！UserSrvc.currentUser）{
 UserSrvc.getUser（）; 
}; 
 
 $ scope.posts = Posts.list（）; 
 
} else {
 $ state.go（'/ login'）; 
} 
}）}）; 
}）; 
  
你会注意到我添加了一个 $ timeout（），否则Angular将不会意识到我们已经对 $ scope 进行了更新。
 
 
请注意，我们有专门的将Firebase绑定到AngularJS的库，名为AngularFire ，它可以完成很多工作自动为您。
 
Using Angularjs.  How do you handle the situation where a person reloads a page and the controller tries to query Firebase using the current user's uid before the Firebase auth event is triggered and has a chance to set the current user?

Details:
The Firebase query require's the user's uid and everything works when navigated to the route via $state.go('/list')

But when a person reloads the page the controller checks for the user which doesn't exist until this event handler fires:
auth.onAuthStateChanged(function(user) {
    if (user) {
      //Set user
      UserSrvc.currentUser = user;
    } else {
      $state.go('/login');
    }
});



app.controller('ListCtrl', function($scope, UserSrvc, Posts ) {

    if (!UserSrvc.currentUser){
        UserSrvc.getUser();
    };

    $scope.posts = Posts.list(); <--THIS GENERATES ERROR, SINCE NO USER YET
})
If Firebase still had the synchronous auth call this wouldn't be an issue since I could do the check and call at the beginning of the controller.

So:

What is the best way to handle this situation.
If user is not logged in, how does UserSrvc.getUser() navigate to $state.go('/login') without having Posts.list() execute?

解决方案
The common way to implement this is by moving the loading of the posts into onAuthStateChanged():
app.controller('ListCtrl', function($scope, UserSrvc, Posts ) {        
  auth.onAuthStateChanged(function(user) { $timeout(function() {
    if (user) {
      UserSrvc.currentUser = user;
      if (!UserSrvc.currentUser){
        UserSrvc.getUser();
      };

      $scope.posts = Posts.list();

    } else {
      $state.go('/login');
    }
  })});
});
You'll note I added a $timeout() in there, since otherwise Angular won't be aware of the update we've made to $scope.

Note that we have a dedicated library binding Firebase to AngularJS called AngularFire, which does a lot of this automatically for you.

                        
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