es6-class-hooks

Use classHooks to wrap any function in your class.

Installation

$ npm install es6-class-hooks --save

Quick Start

To wrap your function use classHooks(classObject, wrapFunc, whitelist) The returned value will be your wrapped class.

use whitelist parameter to whitelist which functions will be wrapped.

Usage example:

const classHooks = require('es6-class-hooks');

class Test {
    constructor() {
        this.someVar = 'just an instance variable';
    }

    foo(x) {
        console.log(`Executing foo with x=${x}`);
    }

    goo(y) {
        console.log(`Executing goo with y=${y}`);
    }
}

function wrapHook(instance, func, args) {
    console.log(`Printing ${instance.someVar}`);
    console.log(`Calling ${func.name} with args: ${JSON.stringify(args)}`);
    const res = func.call(this, ...args);
    console.log(`Called ${func.name} with args: ${JSON.stringify(args)}`);
    return res;
}


const TestWithHooks = classHooks(Test, wrapHook, ['foo']);

const testWithHooks = new TestWithHooks();

testWithHooks.foo(4);
console.log('============');
testWithHooks.goo(3);

//  Printing just an instance variable
//  Calling foo with args: [4]
//  Executing foo with x=4
//  Called foo with args: [4]
//  ============
//  Executing goo with y=3

Updates

v2.0.0 - using receiver to bind this currectly. It is strongly suggested to use regular function as wrapper and bind this to func instead of arrow function so this will pass to the function currectly. Look on the code sample for more information.