【譯】React代碼整潔之道
整潔的代碼不僅僅是正常運(yùn)行的代碼,更是要求易于閱讀、簡(jiǎn)單易懂、組織整齊。
在本文中,我們將研究八種代碼整潔之道。
在閱讀這些建議時(shí),要記住這些只是建議!如果你不同意它們中的任何一個(gè),那也完全沒關(guān)系。
以下這些實(shí)踐,個(gè)人覺得對(duì)我自己編寫 React 代碼很有幫助。
讓我們開始吧!
1. 僅對(duì)一個(gè)條件進(jìn)行渲染
如果需要在條件為 true 時(shí)渲染某些內(nèi)容,而在條件為 false 時(shí)不渲染任何內(nèi)容,不要使 三元表達(dá)式,請(qǐng)改用 &&。
🙅♂️ 不推薦示例:
- import React, { useState } from 'react'
- export const ConditionalRenderingWhenTrueBad = () => {
- const [showConditionalText, setShowConditionalText] = useState(false)
- const handleClick = () =>
- setShowConditionalText(showConditionalText => !showConditionalText)
- return (
- <div>
- <button onClick={handleClick}>Toggle the text</button>
- {/* 三元表達(dá)式 */}
- {showConditionalText ? <p>條件為 True!</p> : null}
- </div>
- )
- }
👍 推薦示例:
- import React, { useState } from 'react'
- export const ConditionalRenderingWhenTrueGood = () => {
- const [showConditionalText, setShowConditionalText] = useState(false)
- const handleClick = () =>
- setShowConditionalText(showConditionalText => !showConditionalText)
- return (
- <div>
- <button onClick={handleClick}>Toggle the text</button>
- {showConditionalText && <p>條件為 True!</p>}
- </div>
- )
- }
2. 每一個(gè)條件都進(jìn)行渲染
如果需要在條件為 true 時(shí)渲染某些內(nèi)容,而在條件為 false 時(shí)渲染其他內(nèi)容。使用三元表達(dá)式!
🙅♂️ 不推薦的示例:
- import React, { useState } from 'react'
- export const ConditionalRenderingBad = () => {
- const [showConditionOneText, setShowConditionOneText] = useState(false)
- const handleClick = () =>
- setShowConditionOneText(showConditionOneText => !showConditionOneText)
- return (
- <div>
- <button onClick={handleClick}>Toggle the text</button>
- {/* 條件 True 和 False 都要渲染內(nèi)容 */}
- {showConditionOneText && <p>條件為 True!</p>}
- {!showConditionOneText && <p>條件為 Flase!</p>}
- </div>
- )
- }
👍 推薦示例:
- import React, { useState } from 'react'
- export const ConditionalRenderingGood = () => {
- const [showConditionOneText, setShowConditionOneText] = useState(false)
- const handleClick = () =>
- setShowConditionOneText(showConditionOneText => !showConditionOneText)
- return (
- <div>
- <button onClick={handleClick}>Toggle the text</button>
- {showConditionOneText ? (
- <p>The condition must be true!</p>
- ) : (
- <p>The condition must be false!</p>
- )}
- </div>
- )
- }
3. Boolean props
Props 值為 true 的推薦省略不寫。
🙅♂️ 不推薦示例:
- import React from 'react'
- const HungryMessage = ({ isHungry }) => (
- <span>{isHungry ? 'I am hungry' : 'I am full'}</span>
- )
- export const BooleanPropBad = () => (
- <div>
- <span>
- <b>This person is hungry: </b>
- </span>
- <HungryMessage isHungry={true} />
- <br />
- <span>
- <b>This person is full: </b>
- </span>
- <HungryMessage isHungry={false} />
- </div>
- )
👍 推薦示例:
- import React from 'react'
- const HungryMessage = ({ isHungry }) => (
- <span>{isHungry ? 'I am hungry' : 'I am full'}</span>
- )
- export const BooleanPropGood = () => (
- <div>
- <span>
- <b>This person is hungry: </b>
- </span>
- {/* 不需要賦值 true,省略 */}
- <HungryMessage isHungry />
- <br />
- <span>
- <b>This person is full: </b>
- </span>
- <HungryMessage isHungry={false} />
- </div>
- )
4. String props
Props 值為 String, 使用雙引號(hào),不使用花括號(hào)或反引號(hào)。
🙅♂️ 不推薦示例:
- import React from 'react'
- const Greeting = ({ personName }) => <p>Hi, {personName}!</p>
- export const StringPropValuesBad = () => (
- <div>
- <Greeting personName={"John"} />
- <Greeting personName={'Matt'} />
- <Greeting personName={`Paul`} />
- </div>
- )
👍 推薦示例:
- import React from 'react'
- const Greeting = ({ personName }) => <p>Hi, {personName}!</p>
- export const StringPropValuesGood = () => (
- <div>
- <Greeting personName="John" />
- <Greeting personName="Matt" />
- <Greeting personName="Paul" />
- </div>
- )
5. Event handler functions
如果一個(gè)事件函數(shù)只接受一個(gè)參數(shù),不需要傳入匿名函數(shù):onChange={e=>handleChange(e)},推薦這種寫法:onChange={handleChange} 。
🙅♂️ 不推薦示例:
- import React, { useState } from 'react'
- export const UnnecessaryAnonymousFunctionsBad = () => {
- const [inputValue, setInputValue] = useState('')
- const handleChange = e => {
- setInputValue(e.target.value)
- }
- return (
- <>
- <label htmlFor="name">Name: </label>
- {/* 事件只有一個(gè)參數(shù),不需要匿名函數(shù)*/}
- <input id="name" value={inputValue} onChange={e => handleChange(e)} />
- </>
- )
- }
👍 推薦示例:
- import React, { useState } from 'react'
- export const UnnecessaryAnonymousFunctionsGood = () => {
- const [inputValue, setInputValue] = useState('')
- const handleChange = e => {
- setInputValue(e.target.value)
- }
- return (
- <>
- <label htmlFor="name">Name: </label>
- <input id="name" value={inputValue} onChange={handleChange} />
- </>
- )
- }
6. components as props
將組件作為參數(shù)傳遞給另一個(gè)組件時(shí),如果該組件不接受任何參數(shù),則無需將該傳遞的組件包裝在函數(shù)中。
🙅♂️ 不推薦示例:
- import React from 'react'
- const CircleIcon = () => (
- <svg height="100" width="100">
- <circle cx="50" cy="50" r="40" stroke="black" stroke-width="3" fill="red" />
- </svg>
- )
- const ComponentThatAcceptsAnIcon = ({ IconComponent }) => (
- <div>
- <p>Below is the icon component prop I was given:</p>
- <IconComponent />
- </div>
- )
- export const UnnecessaryAnonymousFunctionComponentsBad = () => (
- {/* 組件不需要包裝在函數(shù)中 */}
- <ComponentThatAcceptsAnIcon IconComponent={() => <CircleIcon />} />
- )
👍 推薦示例:
- import React from 'react'
- const CircleIcon = () => (
- <svg height="100" width="100">
- <circle cx="50" cy="50" r="40" stroke="black" stroke-width="3" fill="red" />
- </svg>
- )
- const ComponentThatAcceptsAnIcon = ({ IconComponent }) => (
- <div>
- <p>Below is the icon component prop I was given:</p>
- <IconComponent />
- </div>
- )
- export const UnnecessaryAnonymousFunctionComponentsGood = () => (
- <ComponentThatAcceptsAnIcon IconComponent={CircleIcon} />
- )
7. undefined props
如果參數(shù)為 undefined 是允許的,那么不要提供 undefined 作為回退值。
🙅♂️ 不推薦示例:
- import React from 'react'
- const ButtonOne = ({ handleClick }) => (
- <button onClick={handleClick || undefined}>Click me</button>
- )
- const ButtonTwo = ({ handleClick }) => {
- const noop = () => {}
- return <button onClick={handleClick || noop}>Click me</button>
- }
- export const UndefinedPropsBad = () => (
- <div>
- <ButtonOne />
- <ButtonOne handleClick={() => alert('Clicked!')} />
- <ButtonTwo />
- <ButtonTwo handleClick={() => alert('Clicked!')} />
- </div>
- )
👍 推薦示例:
- import React from 'react'
- const ButtonOne = ({ handleClick }) => (
- <button onClick={handleClick}>Click me</button>
- )
- export const UndefinedPropsGood = () => (
- <div>
- <ButtonOne />
- <ButtonOne handleClick={() => alert('Clicked!')} />
- </div>
- )
8. 設(shè)置 state 依賴先前的 state
如果新 state 依賴于先前 state,則始終將 state 設(shè)置為先前 state 的函數(shù)??梢耘幚?React 狀態(tài)更新。
🙅♂️ 不推薦示例:
- import React, { useState } from 'react'
- export const PreviousStateBad = () => {
- const [isDisabled, setIsDisabled] = useState(false)
- const toggleButton = () => setIsDisabled(!isDisabled)
- const toggleButton2Times = () => {
- for (let i = 0; i < 2; i++) {
- toggleButton()
- }
- }
- return (
- <div>
- <button disabled={isDisabled}>
- I'm {isDisabled ? 'disabled' : 'enabled'}
- </button>
- <button onClick={toggleButton}>Toggle button state</button>
- <button onClick={toggleButton2Times}>Toggle button state 2 times</button>
- </div>
- )
- }
👍 推薦示例:
- import React, { useState } from 'react'
- export const PreviousStateGood = () => {
- const [isDisabled, setIsDisabled] = useState(false)
- {/* 推薦設(shè)置為函數(shù) */}
- const toggleButton = () => setIsDisabled(isDisabled => !isDisabled)
- const toggleButton2Times = () => {
- for (let i = 0; i < 2; i++) {
- toggleButton()
- }
- }
- return (
- <div>
- <button disabled={isDisabled}>
- I'm {isDisabled ? 'disabled' : 'enabled'}
- </button>
- <button onClick={toggleButton}>Toggle button state</button>
- <button onClick={toggleButton2Times}>Toggle button state 2 times</button>
- </div>
- )
- }
以上就是我推薦的幾個(gè)寫出整潔的 React 代碼的實(shí)踐。
最后,恭喜你讀完了本文,歡迎留言交流~
原文地址:https://dev.to/thawkin3/react-clean-code-simple-ways-to-write-better-and-cleaner-code-2loa
翻譯/潤(rùn)色:ViktorHub