Add a variable method to the ES6 class

This question already has an answer here: ES6 - declare a prototype method on a class with an import statement 3 answers With an ES6 Class, you can declare methods as follows: class Foo { bar() {} } However, I need to import methods from an external

Destructive assignment to build a new object - is it possible?

This question already has an answer here: Is it possible to destructure an object and generate a new object in a single statement? [duplicate] 2 answers Is it possible to use destructuring assignment syntax to make it possible to extract data objects

Props.store does not work on child components

please help. this.props.store does not work on child components. but the connect(mapStateToProps, mapDispatchToProps) ... is working fine. why doesn't work only child components? 1. parent code (is working fine) import React from 'react'; import Reac

Syntax ES6 and ES8 in React Component

I am new to ES6 with React, and see this inexplicable code in a component: componentWillUnmount() { base.removeBinding(this.ref); this.unsubscribe(); } // ES6 syntax handleToggle(event, toggled){ this.setState({ [event.target.name]: toggled, }); }; /

React - this.props looks undefined

I'm going through a React tutorial. Here's the code that doesn't work when I add a property to a Greeter object let Greeter=React.createClass({ render: ()=>{ let name=this.props.name; return (<div> <h1>Hello {name}!</h1> </div>)

OnClick event handler called on load as opposed to click

I'm new to React and have come across an issue when trying to trigger a function that has been set as a prop. Here is my component: class SamplesInnerLrg extends Component { playSampleAction(sample,sampleId) { console.log(sample); } render() { return

Conditional export in ES2015

Let's say you're developing a polyfill and don't want to shim a class if it already exists in the browser. How can this be done in ES6? The following is not valid because exports is not a statement: if (typeof Foo === 'undefined') { export class Foo

Can not run global babel-node in es2015 mode

so when I install these packages locally they work, but when installed globally (and removed them locally) npm i babel-cli -g npm i -g babel-preset-es2015 npm i -g babel-preset-es2015-node seems like that flag isn't setting es2016-node to look in the

TypeScript inheritance and circular dependencies in SystemJS

I'm using TypeScript with --module system (SystemJS) in a very large project. SystemJS supports cyclic dependencies, and most of the time it works fine. However, when TypeScript inheritance gets involved, things begin to break. For example, if a clas

Security issue of ES2015 model strings

Here's a quote from MDN: Template strings MUST NOT be constructed by untrusted users, because they have access to variables and functions. And an example: `${console.warn("this is",this)}`; // "this is" Window let a = 10; console.warn(

ES2015 / 2016 way of 'typeof varName ===' undefined`?

I'm wallowing in ES2015+ luxury with a few projects right now and am wondering whether I can get rid of the much hated crutch to check for undefined in the new wonderland. Is there a shorter but still exact way to typeof varName === 'undefined' in ES

What is the difference between these ES6 import methods?

This question already has an answer here: Javascript (ES6), export const vs export default 3 answers What is the difference between these import methods? Method 1: import {sum, pi} from "lib/math"; Method 2: import exp, {pi, e} from "lib/ma

How to use the ES6 import with a hyphen

I really don't know how to do this and not sure how to google either. Right now I have this let source = require('vinyl-source-stream'); I would like to change to be import but this doesn't work import {'vinyl-source-stream' as source} from 'vinyl-so

Using Angular 1.x with TypeScript 1.5 and SystemJS

I'm trying to use Angular 1.x with TypeScript 1.5.3 and SystemJS. The index.html page is set up to System.import('bootstrapper') which should start things up. bootstrapper.ts gets compiled to bootstrapper.js and works fine as long as it doesn't use a

How Javascript compares the key of the card

I am using Javascript ES6 features in a node.js application: class pairKey { constructor(x_pos, y_pos) { this._X = x_pos; this._Y = y_pos; } get x() { return this._X; } set x(x_pos) { this._X = x_pos; } get y() { return this._Y; } set y(y_pos) { this

How to disable WebStorm semicolon checking in node.js

How to disable WebStorm semicolon check in node.js? I have tried the following method but they do NOT work: check out the option use semicolon to terminate statement change JavaScript version to ecma6 Any ideas?Settings/Preferences | Editor | Inspect

Symbol.for (string) in ECMAScript 6

It took me a while but I finally figured out what the purpose of symbols in ECMAScript 6 is: avoiding name collision when attaching properties to shared objects - HTML elements e.g. (In case you're stuck on the same question, I recommend this article

ES6 stenographic import

Is there a shorter ES6 way of doing: var assert = require('chai').assert; than import chai from 'chai'; var assert = chai.assert; (chai is the chai-assertion library, in case you haven't heard of it yet.)Yes, you can do it like: import { assert } fro

How to use the ECMAScript 6 syntax with Visual Studio 2013

I am interested in using ECMAScript 6 features in my web application which I am developing using Visual Studio 2013. Currently the syntax does not seems to be working, How can I configure VS to make it work?If you have Resharper installed in your VS