无法访问Firebase对象属性。值显示为未定义的ANGULARFIRE [英] Cannot access Firebase object attributes. Value displayed as undefined ANGULARFIRE
问题描述
我使用用户名访问Firebase内部的引用网址,但是我遇到了一个问题。
我得到一个返回的对象。如果我想访问一个属性,我得到未定义的值,但是如果我添加在我的html {{returnedObj.name}}
中,则会显示该值。 这是为什么?
angular.module('Demo')。controller ('loginCtrl',['$ scope','$ firebase','$ location',function($ scope,$ firebase,$ location){
$ scope.user = {};
$ scope.check = function(){
console.log('https://fabritzio-demo.firebaseio.com/users/'+ $ scope.user.name);
$ scope.returnedObj = $ firebase(新的Firebase('https://fabritzio-demo.firebaseio.com/usuarios/'+ $ scope.user.name))。$ asObject();
alert($ scope.returnedObj.name) ; //返回undefined值
};
}]);
Firebase值是异步加载的。当警报
触发时,该值尚未加载到 $ scope.returnedObj
中。
有两种方法可以处理从Firebase异步加载的值,例如使用 $ loaded
来获得承诺:
$ b $ $ p $
$ scope.returnedObj。$ loaded()。then(function(){
alert($ scope.returnedObj.name);
});
该值显示在模板中,因为Angular监视所有 $ scope
变量进行更改。当数值加载(毫秒后),立即显示。
I want to do a custom login for a demo of my doing, but I encountered a problem.
I use the username to access a reference url inside Firebase, I get a returned object. If I want to access a single attribute, I get the undefined value, but if I add in my html {{returnedObj.name}}
the value is displayed.
Why is that?
angular.module('Demo').controller('loginCtrl', ['$scope', '$firebase', '$location', function($scope, $firebase, $location){
$scope.user = {};
$scope.check = function(){
console.log('https://fabritzio-demo.firebaseio.com/users/' + $scope.user.name);
$scope.returnedObj = $firebase(new Firebase('https://fabritzio-demo.firebaseio.com/usuarios/' + $scope.user.name)).$asObject();
alert($scope.returnedObj.name); // returns undefined value
};
}]);
Firebase values are loaded asynchronously. The value will not yet have been loaded into $scope.returnedObj
when the alert
fires.
There are a couple of ways to handle values loading asynchronously from Firebase, for example using $loaded
to get a promise:
$scope.returnedObj.$loaded().then(function () {
alert($scope.returnedObj.name);
});
The value is displayed in the template because Angular watches all $scope
variables for changes. When the value is loaded (milliseconds later), it is immediately displayed.
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