动态扩展ES6类

Question

how perform easily a kind of mixing or extends dynamic multiple class inheritance in js es6 ?

// example here i have 3 class but they will need to be extends from context.

class Type1 { constructor() {} };
class Type2 { constructor() {} };
class Type3 { constructor() {} };

// and here i have other class inheritance but not need context.

/** return dynamically a class*/
function dynamically_Extends(extendsType) {
    switch (extendsType) {
        case 'type1': return Type1 ;break;
        case 'type2': return Type2 ;break;
        case 'type3': return Type3 ;break;
        default: console.error('class not exist') ;break;
    };
};

class AA {
    constructor(type) {
        //not work: example of extend during constructor?
        extends dynamically_Extends(type); 
        super()
    };
};

class A extends AA{
    constructor(type) {
        super(type)
    };
};

what i want it have something like this when i create objects

const obj1 = new A('type1'); // class heritance: A=>AA=>type1
const obj2 = new A('type2'); // class heritance: A=>AA=>type2
const obj3 = new A('type3'); // class heritance: A=>AA=>type3

i want extends A 2nd time but with a dynamic context according to conditions. Any tips or easy way to perform this during constructor or after ? I want keep class sugar code for all thing.

Answer 1

In addition to all the other benefits classes provide, they also promise a certain API. Dynamic extension would make it relatively much easier to break such promises. (though it's pretty easy to do so without dynamic extensions anyways in JS). Eg does obj1 support Type1.prototype.method1 ? Type2.prototype.method2 ?

An alternative and more traditional (thereby easier to maintain and read) approach to consider, could be to reorganize you class hierarchy. Class Type1 , Type2 , and Type3 could inherit from class A .