EmberJS视图 - 检测是否已呈现所有子视图

Question

场景:

• 呈现集合(异步加载)
• 两个视图:表示笔记列表的NoteView和表示单个笔记的NoteOnListView
• 我必须运行一些代码(masonry.js)来放置它们,但它需要首先渲染所有注释,它需要知道这些子项的计数和属性

我有一个模板,notes.hjs:

{{#each note in controller}}
    {{view App.NoteOnListView}}
{{/each}}

和观点:

App.NotesView = Ember.View.extend({
    didInsertElement: function() {
        console.log('the list has been rendered');
    }
});

App.NoteOnListView = Ember.View.extend({
    didInsertElement: function() {
        console.log('a note has been inserted');
    },
    afterRender: function() {
        console.log('a note has been rendered');
    }
});

控制台输出:

the list has been rendered 
XHR finished loading: "http://localhost:3000/notes"
a note has been rendered
a note has been inserted
a note has been rendered
a note has been inserted
// ... 
a note has been rendered
a note has been inserted
// This is where I need to run code!

我有一些可能的解决方案来解决这个问题,但所有这些解决方案看起来都很糟糕.有没有一种很好的方法我可以告诉NotesView等待它的所有子项都被渲染？

Answer 1

如果将策略更改为继承Ember.CollectionView,则可以使用以下方法接收子视图已完成呈现的通知.

App.CV = Ember.CollectionView.extend( {
    itemViewClass : Ember.View.extend( {
        templateName : 'item'
    } ),

    onChildViewsChanged : function( obj, key ){
        var length = this.get( 'childViews.length' );
        if( length > 0 ){
            Ember.run.scheduleOnce( 'afterRender', this, 'childViewsDidRender' );
        }
    }.observes( 'childViews' ),

    childViewsDidRender : function(){
        //child views have finished rendering!     
    }
} );

这是一个在Ember 1.0 RC2中演示此技术的示例.

有关Ember.run.scheduleOnce的更多信息,请参阅文档.