如何从 Backbone 集合中提取多个属性？

我试图从 Backbone 集合中提取多个属性，但它返回undefined.

收藏

{
    id:1,
    name:"raju",
    age:23,
    sex:male,
    hobbies:..
}
{
    id:2,
    name:"ramesh",
    age:43,
    sex:male,
    hobbies:..
}

... //many models

我正在尝试从集合中获取多个属性。

collection.pluck(["id","name","age","sex"]);

预期产出

[{//multiple attributes},{}]

有没有其他方法可以获取多个属性？

正如@elclanrs 所说，收藏.采摘 http://backbonejs.org/#Collection-pluck提取单个属性，您将不得不使用_.map http://underscorejs.org/#map具有自定义提取功能。就像是

var c = new Backbone.Collection([
    {id: 1, name: "raju", age: 23, sex: "male"},
    {id: 2, name: "ramesh", age: 43, sex: "male"}
]);

var plucked = c.map(function (model) {
    return _.pick(model.toJSON(), ["name", "age"]);
});
console.log(plucked);

还有一个演示http://jsfiddle.net/U7p9u/ http://jsfiddle.net/U7p9u/

您可以通过组合来简化此调用Collection.invoke http://backbonejs.org/#Collection-Underscore-Methods and Model.pick http://backbonejs.org/#Model-Underscore-Methods

var c = new Backbone.Collection([
    {id: 1, name: "raju", age: 23, sex: "male"},
    {id: 2, name: "ramesh", age: 43, sex: "male"}
]);

plucked = c.invoke("pick", ["name", "age"]);  
console.log(plucked);

http://jsfiddle.net/U7p9u/5/ http://jsfiddle.net/U7p9u/5/

本着类似的精神，如果您的提取函数是在模型的原型上定义的：

var M = Backbone.Model.extend({
    mypluck: function () {
        return this.pick("name", "age");
    }
});

var C = Backbone.Collection.extend({
    model: M
});

var c = new C([
    {id: 1, name: "raju", age: 23, sex: "male"},
    {id: 2, name: "ramesh", age: 43, sex: "male"}
]);

var plucked = c.invoke("mypluck");
console.log(plucked);

http://jsfiddle.net/U7p9u/3/ http://jsfiddle.net/U7p9u/3/