AngularFire 0.5.0 $on 'change' 事件未正确触发 [英] AngularFire 0.5.0 $on 'change' event not firing correctly
问题描述
假设我有一组文章,我想通过它进行分页.
Let's say I have a collection of articles I am trying to paginate through.
我正在使用 $on("change")
事件来监听 index
和 limit
I'm using the $on("change")
event to listen for changes to index
and limit
.controller('articlesCtrl', ["$scope", "$firebase", "$stateParams", function($scope, $firebase, $stateParams) {
var limit = 2;
var index = $stateParams.id;
var articlesRef = new Firebase("https://example.firebaseio.com/articles").startAt(null, index).limit(limit);
var obj = $firebase(articlesRef);
obj.$on("change", function() {
var keys = obj.$getIndex();
index = keys[keys.length-1];
console.log(obj);
});
$scope.update = function(){
limit = limit + 2;
obj = $firebase(articlesRef.startAt(null, index).limit(limit));
}
}]);
我注意到 - 在初始加载时,$on("change")
事件会触发两次.
What I'm noticing - is on initial load the $on("change")
event fires twice.
并且每次后续调用更新index
或limit
都不会触发$on("change")代码>事件.
And every subsequent call to update the index
or limit
does not fire the $on("change")
event.
<button type="button" ng-click="update();">Update</button>
推荐答案
每次 $scope.update 触发时,您将 obj
变量分配给一个新的引用.但是,您只需将 obj.$on(change)
附加到原始 obj
.
Each time $scope.update fires, you assign the obj
variable to a new reference. However, you only attach obj.$on(change)
to the original obj
.
这可能可以通过一些实验来优化;这里有一个快速的蛮力让你开始:
This could probably be optimized with some experimentation; here's a quick brute force to get you started:
var limit = 2;
var index = $stateParams.id;
var articlesRef = new Firebase("https://example.firebaseio.com/articles");
$scope.update = update;
update(); // initialize
function update(){
limit = limit + 2;
var obj = $firebase(articlesRef.startAt(null, index).limit(limit));
obj.$on("loaded", function() {
var keys = obj.$getIndex();
index = keys[keys.length-1];
console.log(obj);
});
}
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