Typescript. Simple React components.

#react #typescript #beginners #tutorial

Hello there. I very like to use React and Typescript. Almost in each new project need simple components, like atoms, for example: button, input, checkbox etc. I have some best practices to make it friendly for all members of team, but also with strict typings. Let's get a look, maybe it will be helpful for you too.

Button

import React from 'react';

interface IProps extends React.ButtonHTMLAttributes<HTMLButtonElement> {
  block?: boolean; // Your some custom prop
}

export const Button: React.FunctionComponent<IProps> = ({ block, children, ...shared }) => {
  return <button {...shared}>{children}</button>;
}

Button.defaultProps = {
  type: 'button',
}

That's it. You have custom Button component, that supports all native button attributes with strict typings. You can put common things for all buttons in project, like styles or some business logic.

For use

import React from 'react'

instead of

import * as React from 'react'

add in your tsconfig.json property esModuleInterop: true

Input

import React from 'react';

interface IProps extends Omit<React.InputHTMLAttributes<HTMLInputElement>, 'onChange' | 'value'> {
  value: string;

  onChange(value: string): void;
}

export const Input: React.FunctionComponent<IProps> = ({ children, onChange, ...shared }) => {
  return <input onChange={e => onChange(e.target.value)} {...shared} />;
}

Input.defaultProps = {
  type: 'text',
};

The Omit helper type was added in Typescript 3.5. If you use previous version of Typescript, just add this string:

type Omit<T, K> = Pick<T, Exclude<keyof T, K>>

Checkbox

import React from 'react';

interface IProps extends Omit<React.InputHTMLAttributes<HTMLInputElement>, 'onChange'> {
  onChange(value: boolean): void;
}

export const Checkbox: React.FunctionComponent<IProps> = ({ children, 
onChange, ...shared }) => {
  return <input onChange={e => onChange(e.target.checked)} {...shared} />
}

Checkbox.defaultProps = {
  type: 'checkbox',  
}

Now you can use it like here:

<Checkbox checked={false} onChange={toggleCheckbox} />

It is end of small tutorial. If it will be helpful for someone, I can continue to explain some good things of React and Typescript. Thanks for attention.

Top comments (11)

Stefano Armenes • Aug 27 '19

You can also use React.FC instead of React.FunctionComponent 😃

Maksim • Aug 27 '19

Thx) Awesome!

Kris Temmerman • Aug 27 '19

Nice article! you've made a small typo

export const Button: React.FunctionComonent<IProps> = ({ block, ...shared }) => {
  return <button {...shared}>{children}</button>;
}

should be Component or .FC

Maksim • Aug 27 '19

React.FC and React.FunctionComponent is the same

Kris Temmerman • Aug 28 '19 • Edited

Yeah I know but look closely.
thepracticaldev.s3.amazonaws.com/i...

Maksim • Aug 28 '19

Oh, sorry! Thanks)

HCB • Aug 28 '19 • Edited

Instead of defaultProps, I use:

export const Button: React.FunctionComponent<IProps> = ({ block, children, type = 'button', ...shared }) => {
  return <button type={type} {...shared}>{children}</button>;

}

Ruslan Shashkov • Nov 11 '19 • Edited

It also would be better to use Extract on the shared button props to extract only InputHTMLAttributes<HTMLInputElement> props for <button {...extractedProps}>. In case if you decided to use some custom props for example loading: boolean it will also be sent to <button/> and cause warnings that your loading prop is not in default button props.

Eric Andre • Aug 28 '19

I'm a little confused. You keep saying this provides "strict" typing, which I assume you mean strong typing. Since typescript happens before runtime and converts the code to javascript which will be executed in a javascript runtime, which is weakly typed your code will also be weakly typed. Typescript won't magically make the javascript runtime strongly typed. Are you meaning to say it provides static typing? Sorry, this very much is a semantic issue I'm trying to clarify.