backbone.js - 如何在 Backbone.js 的模型中存储对集合的引用？

Question

创建新集合（选择）时，我想在其上设置一个属性（例如：_question），该属性链接回包含模型（MultipleChoiceQuestion）

Answer 1

这花了我很多时间来弄清楚，所以以防将来有人遇到这个问题......这是我最终编写的代码。

我发现，与 Model 不同，Collection 的 initialize() 函数接受 2 个参数。第一个是models（这是您可以用来初始化集合的模型列表）。第二个是options（你想要什么）。有一段时间，我的 Collection 最初只有 1 个模型，但我不知道为什么。原来我把我的传给options了models田野。

包含模型：

m.MultipleChoiceQuestion = Backbone.Model.extend({
    initialize: function(){
        //NULL as first parameter because we don't want models
        this.choices = new c.Choices(null, { 
            _question: this //this is referring to current question
        }); //choices Collection is this
    }
});

该系列

c.Choices = Backbone.Collection.extend({
    initialize: function(models, options){
        this._question = options._question;
    },
    model: m.Choice
});

Answer 2

我实际上发现虽然我的第一个答案在技术上有效，但有一个插件可以处理在模型中存储集合（并创建适当的 One->Many、One->One 和 Many->One 关系

https://github.com/PaulUithol/Backbone-relational

使用该插件，您将父问题存储为属性

m.MultipleChoiceQuestion = Backbone.RelationalModel.extend({
    relations: [{
        type: Backbone.HasMany,
        key: 'choices', //says to store the collection in the choices attribute
        relatedModel: m.Choice, //knows we are talking about the choices models
        includeInJSON: true, //when we do toJSON() on the Question we want to show serialize the choices fully
        reverseRelation: {
            key: 'question', //in the CHOICE object there will be an attribute called question which contains a reference to the question 
            includeInJSON: false //when we do .toJSON on a CHOICE we don't want to show the question object (or maybe we want to show the ID property in which case we set it to "id")
        }
    }],
    coolFunction: function () {
        this.get('choices').each(function(choice){
            choice.doSomethingChoicey();
        });
    }
});

所以现在如果我们在选择模型中，我们可以完全引用父问题中的任何内容：

m.Choice = m.RelationalModel.extend({
    coolFunction: function(){
        this.get('question').doSomemethingQuestiony();
        var question_numer = this.get('question').get('question_number');
    }
});