@activeprospect/old 中文文档教程
old
使 ES6 类的 'new' 关键字可选
Usage
npm install old
var old = require('old')
class Class {
// ...
}
var Class2 = old(Class)
Class() // throws error
Class2() // creates an instance of Class
Rationale
对于 ES5“构造函数”函数，一个常见的模式是使 new 关键字可选，方法如下：
function Foo () {
if (!(this instanceof Foo)) return new Foo()
// do constructor stuff
}
最近，ES6 引入了类来替换构造函数。 但是，如果这些类是在没有 new 的情况下实例化的，则会抛出错误：TypeError: Class constructor Foo cannot be invoked without 'new'。 这个模块使 new 成为可选的，即使对于这些 ES6 类也是如此。
Credit
- Thank you to Sorella in ##javascript (Freenode) for the clean solution
- Thanks to slikts in ##javascript for the name idea
old
Make the 'new' keyword optional for ES6 classes
Usage
npm install old
var old = require('old')
class Class {
// ...
}
var Class2 = old(Class)
Class() // throws error
Class2() // creates an instance of Class
Rationale
With ES5 "constructor" functions, a common pattern is to make the new keyword optional by doing something like the following:
function Foo () {
if (!(this instanceof Foo)) return new Foo()
// do constructor stuff
}
Recently, ES6 introduced classes to replace constructor functions. However, if these classes are instantiated without new, an error is thrown: TypeError: Class constructor Foo cannot be invoked without 'new'. This module makes new optional, even for these ES6 classes.
Credit
- Thank you to Sorella in ##javascript (Freenode) for the clean solution
- Thanks to slikts in ##javascript for the name idea
