A simple library for multiple inheritance in JavaScript.
npm install extend-basesThis library can be used to achieve multiple inheritance in JavaScript, but it sets itself apart from other libraries
for multiple inheritance because it isolates the base classes and prevents the properties and methods from colliding,
while still allowing easy access to the properties and methods of the base classes.
Simply run:
``
npm add extend-bases
Or:
`
yarn add extend-bases
To import:
`typescript`
import {bases, defineProperties, isInstanceOf} from "extend-bases";
Or:
`typescript`
const {bases, defineProperties, isInstanceOf} = require("extend-bases");
To inherit from multiple bases simply extend from bases(Class1, Class2, ...). In the constructor pass the *super
instances* of the classes to the constructor.
Then you can access the base properties and methods directly from this., the first class with that property or method
will be given precedence.
To access a particular base use this.bases[index].
Replace all instances of v instanceof Class with isInstanceOf(v, Class), it’s just that simple.
- Read the Handy manual, it’s very simple & small
and gives enough information to get started.
- Then read the Documentation. it’s not too big
and easy to go through.
- Then, if you have enough time or are interested, read the tests and source code of the project.
This library uses Proxies, so sadly no IE11 support, but otherwise this library also imports es-shims
for Reflect.ownKeys(ES6 but used very often and an es-shim exists for it) and Array.prototype.flatMap`(ES2019, very
new), which were found to be the bottlenecks, for some browsers.
This library uses proxies for easy access in the class instances, and it merges the prototypes of the base classes, but
for isolation of base classes it creates a new function wrapping the method call. It’s just best to look at the source
code for this.
The library is by default written in TypeScript, which you all should be using if you aren’t, for great code completion.
The details of the TypeScript definitions are a bit fiddly, so it’s best not to worry about them, they work, or
you can just look at the source code.
Feel free to open a pull request, fix bugs, or read the source code. It’s all up to you.