是否可以使用 2 个工厂函数来填充 1 个实例？

Question

使用单个 factory function 填充实例非常简单。在下面的示例中，我使用工厂函数 aircraftFactory() 创建一个名为 supermarine 的新实例。但是我不确定如何构建它以便 aircraftFactory() 和 engines() 可以一起使用来创建 supermarine。

"use strict"

function aircraftFactory(x) {
    return {
        manufacturer: x.manufacturer,
        factory: x.factory
    }
}

function engines(x) {
    return {
        numberOfEngines: x.numberOfEngines,
        costPerEngine: x.costPerEngine
    }
}

let supermarine = aircraftFactory({manufacturer: 'Supermarine', factory: 'Southampton'});

document.querySelector('.output').textContent = supermarine.manufacturer;

<div class='output'></div>

我试过像这样将它们链接在一起，但它抛出了一个错误。

未捕获类型错误：aircraftFactory(...).engines 不是函数

let supermarine = aircraftFactory({manufacturer: 'Supermarine', factory: 'Southampton'}).engines({numberOfEngines: 1, costPerEngine: 35000});

我知道一定有一个模式，但我找不到示例或弄清楚。感谢您的帮助！

Answer 1

我想我有一个建议给你：

function engines(x) {
    return {
        numberOfEngines: x.numberOfEngines,
        costPerEngine: x.costPerEngine
    }
}

如果你通过引擎：

function aircraftFactory(x, engine) {
    let aircraft = {
        manufacturer: x.manufacturer,
        factory: x.factory
    };

    if (engine) {
      aircraft.numberOfEngines = engine.numberOfEngines;
      aircraft.costPerEngine = engine.costPerEngine;
    }

    return aircraft;
}

您可以像这样创建一个实例：

let aircraft = aicraftFactory(x, engineFactory(y));

但是如果您想在不知道名称的情况下创建属性：

function aircraftFactory(x, extended) {
    let aircraft = {
        manufacturer: x.manufacturer,
        factory: x.factory
    };

    if (engine) {
        for (let key in extended) {
            aircraft[key] = extended[key];
        }
    }

    return aircraft;
}

Answer 2

要将 engines 扩展到 aircraftFactory，您需要使用 prototype

Prototypes extends/inherit your properties and methods.

试试这个

"use strict"

function aircraftFactory(x) {
  this.manufacturer = x.manufacturer;
  this.factory = x.factory;
}

function engines(x) {
    return {
        numberOfEngines: x.numberOfEngines,
        costPerEngine: x.costPerEngine
    }
}

//This is where you extend engines
aircraftFactory.prototype.engines = engines;

//Create the instance of aircraftFactory
let supermarine = new aircraftFactory({manufacturer: 'Supermarine', factory: 'Southampton'}).engines({numberOfEngines: 1, costPerEngine: 35000});

是否可以使用 2 个工厂函数来填充 1 个实例？

Is it possible to use 2 factory functions to populate 1 instance?

javascript

factory-pattern