我如何使用 UnderscoreJS 通过它们的“id"联合/合并两个集合 [英] How do I union/merge two Collections by their 'id' using UnderscoreJS

问题描述

我有两个集合(菜单和订单)

I have two collections (Menu and Orders)

菜单集合包含 Item 对象数组

Menu collection contains array of Item objects

[{'id': '1', 'name': 'apple'}, {'id': '2', 'name': 'orange'}]

并且订单集合还包含Item对象数组

And Orders collection also contains array of Item objects

[{'id': '1', 'quantity': '0'}]

并且我希望它们通过 ID 将它们的属性合并到另一个集合中(这仅用于模板目的):

And I want them merged together their attributes by ID into another collection (this is needed for templating purposes only):

[{'id': '1', 'name': 'apple', 'quantity': '1'}, {'id': '2', 'name': 'orange'}]

是否有下划线方法或者我需要为此定义一个函数?[似乎我在下划线上尝试了所有合并功能，但没有一个按我预期的方式工作]

Is there a underscore method on this or I need to define a function for this? [it seems i tried all merging functions on underscore but none of them works the way I expected]

推荐答案

假设您的集合是 Backbone 集合

Assuming your collections are Backbone collections

var menus = new Backbone.Collection([
    {'id': '1', 'name': 'apple'}, 
    {'id': '2', 'name': 'orange'}
]);

var orders = new Backbone.Collection([{'id': '1', 'quantity': 1}]);

您可以利用在集合上代理的函数和 collection.get :

you can take advantage of the functions proxied on collections and of collection.get :

var merged = menus.map(function(menu) {
    var id = menu.get('id'),
        order = orders.get(id);

    if (!order) return menu.toJSON();

    return _.extend(menu.toJSON(), order.toJSON());
});

还有一个可以玩的小提琴 http://jsfiddle.net/bs6jN/

And a Fiddle to play with http://jsfiddle.net/bs6jN/

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