Backbone.js：将值从Collection传递到每个模型

Question

我需要在初始化时将视图中的值传递给集合内的每个模型。

直到收集，我们才能在Backbone.Collection构造函数中传递“选项”。

之后，有什么技术可以将一些“选项”传递给集合中的每个模型？

var Song = Backbone.Model.extend({
    defaults: {
        name: "Not specified",
        artist: "Not specified"
    },
    initialize: function (attributes, options) {
        //Need the some_imp_value accessible here
    },
});

var Album = Backbone.Collection.extend({
    model: Song

    initialize: function (models, options) {
        this.some_imp_value = option.some_imp_value;
    }
});

Answer 1

您可以覆盖“ _prepareModel”方法。

var Album = Backbone.Collection.extend({
    model: Song

    initialize: function (models, options) {
        this.some_imp_value = option.some_imp_value;
    },

    _prepareModel: function (model, options) {
        if (!(model instanceof Song)) {
          model.some_imp_value = this.some_imp_value;
        }
        return Backbone.Collection.prototype._prepareModel.call(this, model, options);
    }
});

现在，您可以在“ initialize”中查看传递给模型的属性，您将获得some_imp_value，然后可以在模型上适当地进行设置。

Answer 2

尽管它似乎没有记录，但我发现至少在主干的最新版本（v1.3.3）中，传递给集合的options对象传递给每个子模型，并扩展到该集合生成的其他选项中。 我没有花时间确认旧版本是否属于这种情况。

例：

var Song = Backbone.Model.extend({
    defaults: {
        name: "Not specified",
        artist: "Not specified"
    },
    initialize: function (attributes, options) {
        //passed through options
        this.some_imp_value = options.some_imp_value

        //accessing parent collection assigned attributes
        this.some_other_value = this.collection.some_other_value
    },
});

var Album = Backbone.Collection.extend({
    model: Song

    initialize: function (models, options) {
        this.some_other_value = "some other value!";
    }
});

var myAlbum = new Album([array,of,models],{some_imp_value:"THIS IS THE VALUE"});

注意：我不确定选项对象是否传递给后续的Collection.add事件