From a92ee4862f11b6f6a0d7cf55a5eee20978466ddc Mon Sep 17 00:00:00 2001
From: Dreamacro <305009791@qq.com>
Date: Wed, 3 Jul 2019 13:49:41 +0800
Subject: [PATCH] Migration: Select to hooks component

---
 src/components/Select/index.tsx | 163 +++++++++++++-------------------
 1 file changed, 66 insertions(+), 97 deletions(-)

diff --git a/src/components/Select/index.tsx b/src/components/Select/index.tsx
index aee1142..f670b4e 100644
--- a/src/components/Select/index.tsx
+++ b/src/components/Select/index.tsx
@@ -1,4 +1,4 @@
-import * as React from 'react'
+import React, { useRef, useLayoutEffect, useState, useMemo } from 'react'
 import classnames from 'classnames'
 import { Icon } from '@components'
 import { BaseComponentProps } from '@models'
@@ -17,81 +17,59 @@ interface SelectProps extends BaseComponentProps {
     onSelect?: (value: OptionValue, e: React.MouseEvent<HTMLLIElement>) => void
 }
 
-interface SelectState {
-    dropdownListStyles: React.CSSProperties
-    showDropDownList: boolean,
-    hasCreateDropList: boolean
-}
+export function Select (props: SelectProps) {
+    const { value, onSelect, children, className: cn, style } = props
 
-export class Select extends React.Component<SelectProps, SelectState> {
+    const portalRef = useRef<HTMLDivElement>()
+    const attachmentRef = useRef<HTMLDivElement>()
+    const targetRef = useRef<HTMLDivElement>()
 
-    // portal container
-    $container: Element
 
-    // drop down list
-    $attachment = React.createRef<HTMLDivElement>()
-
-    // target position element
-    $target = React.createRef<HTMLDivElement>()
-
-    state = {
-        dropdownListStyles: {},
-        showDropDownList: false,
-        hasCreateDropList: false
-    }
-
-    componentDidMount () {
-        document.addEventListener('click', this.handleGlobalClick, true)
-        this.setState({ dropdownListStyles: this.calculateAttachmentPosition() })
-    }
-
-    componentWillUnmount () {
-        if (this.state.hasCreateDropList) {
-            document.body.removeChild(this.$container)
+    useLayoutEffect(() => {
+        document.addEventListener('click', handleGlobalClick, true)
+        return () => {
+            document.addEventListener('click', handleGlobalClick, true)
+            if (portalRef.current) {
+                document.body.removeChild(portalRef.current)
+            }
         }
-        document.removeEventListener('click', this.handleGlobalClick, true)
-    }
+    }, [])
 
-    shouldComponentUpdate (nextProps, nextState) {
-        if (nextProps.value === this.props.value && nextState.showDropDownList === this.state.showDropDownList) {
-            return false
+    const [showDropDownList, setShowDropDownList] = useState(false)
+    const [hasCreateDropList, setHasCreateDropList] = useState(false)
+    const dropdownListStyles = useMemo(() => {
+        if (targetRef.current) {
+            const targetRectInfo = targetRef.current.getBoundingClientRect()
+            return {
+                top: Math.floor(targetRectInfo.top) - 10,
+                left: Math.floor(targetRectInfo.left) - 10
+            }
         }
-        return true
-    }
+        return {}
+    }, [])
 
-    handleShowDropList = () => {
-        if (!this.state.hasCreateDropList) {
-            // create container element
-            const container = document.createElement('div')
-            document.body.appendChild(container)
-            this.$container = container
-            this.setState({
-                hasCreateDropList: true
-            })
-        }
-        this.setState({
-            showDropDownList: true
-        })
-    }
-
-    private handleGlobalClick = (e) => {
-        const el = this.$attachment.current
+    function handleGlobalClick (e) {
+        const el = attachmentRef.current
 
         if (el && !el.contains(e.target)) {
-            this.setState({ showDropDownList: false })
+            setShowDropDownList(false)
         }
     }
 
-    private calculateAttachmentPosition () {
-        const targetRectInfo = this.$target.current.getBoundingClientRect()
-
-        return {
-            top: Math.floor(targetRectInfo.top) - 10,
-            left: Math.floor(targetRectInfo.left) - 10
+    function handleShowDropList (e) {
+        if (!hasCreateDropList) {
+            if (!portalRef.current) {
+                // create container element
+                const container = document.createElement('div')
+                document.body.appendChild(container)
+                portalRef.current = container
+            }
+            setHasCreateDropList(true)
         }
+        setShowDropDownList(true)
     }
 
-    private getSelectedOption = (value: OptionValue, children: React.ReactNode) => {
+    const matchChild = useMemo(() => {
         let matchChild: React.ReactElement<any> = null
 
         React.Children.forEach(children, (child: React.ReactElement<any>) => {
@@ -101,13 +79,9 @@ export class Select extends React.Component<SelectProps, SelectState> {
         })
 
         return matchChild
-    }
+    }, [value, children])
 
-    private hookChildren = (
-        children: React.ReactNode,
-        value: OptionValue,
-        onSelect: SelectProps['onSelect']
-    ) => {
+    const hookedChildren = useMemo(() => {
         return React.Children.map(children, (child: React.ReactElement<any>) => {
             if (!child.props || !child.type) {
                 return child
@@ -123,43 +97,40 @@ export class Select extends React.Component<SelectProps, SelectState> {
             return React.cloneElement(child, Object.assign({}, child.props, {
                 onClick: (e: React.MouseEvent<HTMLLIElement>) => {
                     onSelect(child.props.value, e)
-                    this.setState({ showDropDownList: false })
+                    setShowDropDownList(false)
                     rawOnClickEvent && rawOnClickEvent(e)
                 },
                 className
             }))
         })
-    }
+    }, [children, value, onSelect])
 
-    render () {
-        const { value, onSelect, children, className: cn, style } = this.props
-        const { dropdownListStyles, showDropDownList, hasCreateDropList } = this.state
-        const matchChild = this.getSelectedOption(value, children)
-        const dropDownList = (
-            <div
-                className={classnames('select-list', { 'select-list-show': showDropDownList })}
-                ref={this.$attachment}
-                style={dropdownListStyles}
-            >
-                <ul className="list">
-                    {this.hookChildren(children, value, onSelect)}
-                </ul>
-            </div>
-        )
+    const dropDownList = (
+        <div
+            className={classnames('select-list', { 'select-list-show': showDropDownList })}
+            ref={attachmentRef}
+            style={dropdownListStyles}
+        >
+            <ul className="list">
+                { hookedChildren }
+            </ul>
+        </div>
+    )
 
-        return <>
+    return (
+        <>
             <div
                 className={classnames('select', cn)}
                 style={style}
-                ref={this.$target}
-                onClick={this.handleShowDropList}
+                ref={targetRef}
+                onClick={handleShowDropList}
             >
                 {matchChild && matchChild.props && matchChild.props.children}
                 <Icon type="triangle-down" />
             </div>
-            {hasCreateDropList && createPortal(dropDownList, this.$container)}
+            {hasCreateDropList && createPortal(dropDownList, portalRef.current)}
         </>
-    }
+    )
 }
 
 interface OptionProps extends BaseComponentProps {
@@ -169,13 +140,11 @@ interface OptionProps extends BaseComponentProps {
     onClick?: (e: React.MouseEvent<HTMLLIElement>) => void
 }
 
-export class Option extends React.Component<OptionProps, {}> {
-    render () {
-        const { className: cn, style, key, disabled = false, children, onClick = () => {} } = this.props
-        const className = classnames('option', { disabled }, cn)
+export const Option: React.SFC<OptionProps> = props => {
+    const { className: cn, style, key, disabled = false, children, onClick = () => {} } = props
+    const className = classnames('option', { disabled }, cn)
 
-        return (
-            <li className={className} style={style} key={key} onClick={onClick}>{children}</li>
-        )
-    }
+    return (
+        <li className={className} style={style} key={key} onClick={onClick}>{children}</li>
+    )
 }