-
var
는function-scoped
이고,let
,const
는block-scoped
입니다. -
function-scoped
와block-scoped
가 무슨말이냐?
import {forwardRef, useImperativeHandle, ForwardRefExoticComponent, RefAttributes, Ref} from "react"; | |
export type Handle<T> = T extends ForwardRefExoticComponent<RefAttributes<infer T2>> ? T2 : never; | |
export const Parent = (props: {})=> { | |
let childHandle: Handle<typeof Child>; | |
return ( | |
<div onClick={()=>childHandle.SayHi()}> | |
<Child name="Bob" ref={c=>childHandle = c}/> | |
</div> |
const mapItemSchema = new mongoose.Schema({ | |
name: String, | |
location: { | |
// It's important to define type within type field, because | |
// mongoose use "type" to identify field's object type. | |
type: {type: String, default: 'Point'}, | |
// Default value is needed. Mongoose pass an empty array to | |
// array type by default, but it will fail MongoDB's pre-save | |
// validation. | |
coordinates: {type: [Number], default: [0, 0]} |
I've been using create-react-app lately as I find it very useful to kick things off while starting a project. I almost always follow JavaScript Standard Style and I found myself googling it so I figured out I should write it down.
I really like keeping dependencies as local as possible but if you prefer you can install it globally.
yarn add standard --dev
or
// See https://blog.isquaredsoftware.com/presentations/react-redux-ts-intro-2020-12/#/36 for slides | |
// My basic render function structure: | |
function RenderLogicExample({ | |
someBoolean, // 1) Destructure values from `props` object | |
someList, | |
}) { | |
// 2) Declare state values | |
const [a, setA] = useState(0); | |
const [b, setB] = useState(0); |
// connect() is a function that injects Redux-related props into your component. | |
// You can inject data and callbacks that change that data by dispatching actions. | |
function connect(mapStateToProps, mapDispatchToProps) { | |
// It lets us inject component as the last step so people can use it as a decorator. | |
// Generally you don't need to worry about it. | |
return function (WrappedComponent) { | |
// It returns a component | |
return class extends React.Component { | |
render() { | |
return ( |
Hi Nicholas,
I saw you tweet about JSX yesterday. It seemed like the discussion devolved pretty quickly but I wanted to share our experience over the last year. I understand your concerns. I've made similar remarks about JSX. When we started using it Planning Center, I led the charge to write React without it. I don't imagine I'd have much to say that you haven't considered but, if it's helpful, here's a pattern that changed my opinion:
The idea that "React is the V in MVC" is disingenuous. It's a good pitch but, for many of us, it feels like in invitation to repeat our history of coupled views. In practice, React is the V and the C. Dan Abramov describes the division as Smart and Dumb Components. At our office, we call them stateless and container components (view-controllers if we're Flux). The idea is pretty simple: components can't
안녕하세요. 사원사업부의 마루야마@h13i32maru입니다. 최근의 Web 프론트엔드의 변화는 매우 격렬해서, 조금 눈을 땐 사이에 점점 새로운 것이 나오고 있더라구요. 그런 격렬한 변화중 하나가 ES6이라는 차세대 JavaScript의 사양입니다. 이 ES6는 현재 재정중으로 집필시점에서는 Draft Rev31이 공개되어있습니다.
JavaScript는 ECMAScript(ECMA262)라는 사양을 기반으로 구현되어있습니다. 현재 모던한 Web 브라우저는 ECMAScript 5.1th Edition을 기반으로 한 JavaScript실행 엔진을 탑재하고 있습니다. 그리고 다음 버전인 ECMAScript 6th Edition이 현재 재정중으로, 약칭으로 ES6이라는 명칭이 사용되고 있습니다.
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#add 'node_modules' to .gitignore file | |
git rm -r --cached node_modules | |
git commit -m 'Remove the now ignored directory node_modules' | |
git push origin <branch-name> |