Backbone：在变量中传递下划线模板

Question

我使用Underscore.js的Backbones模板有问题。 我将所有模板都放在单独的变量中，并且当我将它们传递给我的模型时，我会开始使用＃34; Uncaught TypeError：无法读取属性＆＃39; html＆＃39;未定义＆＃34;

这是我的代码，

var YetiBoxView = Backbone.View.extend({
    tagName: 'li',

    template_online : yetibox_status_online,
    template_offline : yetibox_status_offline,
    template_inactive : yetibox_status_inactive,


    initialize: function(){
        this.render();
    },

    render: function(){
        if( this.model.toJSON().status == "ONLINE") {
            this.$el.html(this.template_online(this.model.toJSON()));
        } else if (this.model.toJSON().status == "OFFLINE"){
            this.$el.html(this.template_offline(this.model.toJSON()));
        } else if(this.model.toJSON().status == "INACTIVE"){
            console.log(this.model.toJSON());
            this.$el.html(this.template_inactive(this.model.toJSON()));
    }}
});


var YetiBoxCollectionView = Backbone.View.extend({

    el : '#status_list',

    render: function(){
        this.collection.each(function(yetibox){
            var yetibox_view = new YetiBoxView({model: yetibox});
            this.$el.append(yetibox_view.el);
        }, this);
    }
});