From abcad059542d71fbd44671766388e1af3c79776f Mon Sep 17 00:00:00 2001
From: JeremyWuuuuu <15975785+JeremyWuuuuu@users.noreply.github.com>
Date: Sat, 22 Oct 2022 12:44:06 +0800
Subject: [PATCH] refactor(components): [carousel]

* Extract component logic out of .vue file.
* Reorganize code for better readability.
---
 packages/components/carousel/src/carousel.ts  |   3 -
 packages/components/carousel/src/carousel.vue | 272 ++---------------
 packages/components/carousel/src/instance.ts  |   3 +
 .../components/carousel/src/use-carousel.ts   | 276 ++++++++++++++++++
 4 files changed, 302 insertions(+), 252 deletions(-)
 create mode 100644 packages/components/carousel/src/instance.ts
 create mode 100644 packages/components/carousel/src/use-carousel.ts

diff --git a/packages/components/carousel/src/carousel.ts b/packages/components/carousel/src/carousel.ts
index 1d659472bd1cac..89213bd5d7ae32 100644
--- a/packages/components/carousel/src/carousel.ts
+++ b/packages/components/carousel/src/carousel.ts
@@ -1,6 +1,5 @@
 import { buildProps, isNumber } from '@element-plus/utils'
 import type { ExtractPropTypes } from 'vue'
-import type Carousel from './carousel.vue'
 
 export const carouselProps = buildProps({
   initialIndex: {
@@ -64,5 +63,3 @@ export const carouselEmits = {
 
 export type CarouselProps = ExtractPropTypes<typeof carouselProps>
 export type CarouselEmits = typeof carouselEmits
-
-export type CarouselInstance = InstanceType<typeof Carousel>
diff --git a/packages/components/carousel/src/carousel.vue b/packages/components/carousel/src/carousel.vue
index ab9047fbda5490..44138ecf6f51d4 100644
--- a/packages/components/carousel/src/carousel.vue
+++ b/packages/components/carousel/src/carousel.vue
@@ -62,60 +62,39 @@
 </template>
 
 <script lang="ts" setup>
-import {
-  computed,
-  getCurrentInstance,
-  onBeforeUnmount,
-  onMounted,
-  provide,
-  ref,
-  shallowRef,
-  unref,
-  watch,
-} from 'vue'
-import { throttle } from 'lodash-unified'
-import { useResizeObserver } from '@vueuse/core'
-import { debugWarn, isString } from '@element-plus/utils'
+import { computed, unref } from 'vue'
 import { ElIcon } from '@element-plus/components/icon'
 import { ArrowLeft, ArrowRight } from '@element-plus/icons-vue'
-import { useNamespace, useOrderedChildren } from '@element-plus/hooks'
-import { carouselContextKey } from '@element-plus/tokens'
+import { useNamespace } from '@element-plus/hooks'
 import { carouselEmits, carouselProps } from './carousel'
-import type { CarouselItemContext } from '@element-plus/tokens'
+import { useCarousel } from './use-carousel'
 
+const COMPONENT_NAME = 'ElCarousel'
 defineOptions({
-  name: 'ElCarousel',
+  name: COMPONENT_NAME,
 })
 
 const props = defineProps(carouselProps)
 const emit = defineEmits(carouselEmits)
-const ns = useNamespace('carousel')
-const COMPONENT_NAME = 'ElCarousel'
-const THROTTLE_TIME = 300
-
 const {
-  children: items,
-  addChild: addItem,
-  removeChild: removeItem,
-} = useOrderedChildren<CarouselItemContext>(
-  getCurrentInstance()!,
-  'ElCarouselItem'
-)
-
-// refs
-const activeIndex = ref(-1)
-const timer = ref<ReturnType<typeof setInterval> | null>(null)
-const hover = ref(false)
-const root = ref<HTMLDivElement>()
-
-// computed
-const arrowDisplay = computed(
-  () => props.arrow !== 'never' && !unref(isVertical)
-)
-
-const hasLabel = computed(() => {
-  return items.value.some((item) => item.props.label.toString().length > 0)
-})
+  activeIndex,
+  arrowDisplay,
+  hasLabel,
+  hover,
+  isCardType,
+  items,
+  handleButtonEnter,
+  handleButtonLeave,
+  handleIndicatorClick,
+  handleMouseEnter,
+  handleMouseLeave,
+  setActiveItem,
+  prev,
+  next,
+  throttledArrowClick,
+  throttledIndicatorHover,
+} = useCarousel(props, emit, COMPONENT_NAME)
+const ns = useNamespace('carousel')
 
 const carouselClasses = computed(() => {
   const classes = [ns.b(), ns.m(props.direction)]
@@ -136,211 +115,6 @@ const indicatorsClasses = computed(() => {
   return classes
 })
 
-const isCardType = computed(() => props.type === 'card')
-const isVertical = computed(() => props.direction === 'vertical')
-
-// methods
-const throttledArrowClick = throttle(
-  (index: number) => {
-    setActiveItem(index)
-  },
-  THROTTLE_TIME,
-  { trailing: true }
-)
-
-const throttledIndicatorHover = throttle((index: number) => {
-  handleIndicatorHover(index)
-}, THROTTLE_TIME)
-
-function pauseTimer() {
-  if (timer.value) {
-    clearInterval(timer.value)
-    timer.value = null
-  }
-}
-
-function startTimer() {
-  if (props.interval <= 0 || !props.autoplay || timer.value) return
-  timer.value = setInterval(() => playSlides(), props.interval)
-}
-
-const playSlides = () => {
-  if (activeIndex.value < items.value.length - 1) {
-    activeIndex.value = activeIndex.value + 1
-  } else if (props.loop) {
-    activeIndex.value = 0
-  }
-}
-
-function setActiveItem(index: number | string) {
-  if (isString(index)) {
-    const filteredItems = items.value.filter(
-      (item) => item.props.name === index
-    )
-    if (filteredItems.length > 0) {
-      index = items.value.indexOf(filteredItems[0])
-    }
-  }
-  index = Number(index)
-  if (Number.isNaN(index) || index !== Math.floor(index)) {
-    debugWarn(COMPONENT_NAME, 'index must be integer.')
-    return
-  }
-  const itemCount = items.value.length
-  const oldIndex = activeIndex.value
-  if (index < 0) {
-    activeIndex.value = props.loop ? itemCount - 1 : 0
-  } else if (index >= itemCount) {
-    activeIndex.value = props.loop ? 0 : itemCount - 1
-  } else {
-    activeIndex.value = index
-  }
-  if (oldIndex === activeIndex.value) {
-    resetItemPosition(oldIndex)
-  }
-  resetTimer()
-}
-
-function resetItemPosition(oldIndex?: number) {
-  items.value.forEach((item, index) => {
-    item.translateItem(index, activeIndex.value, oldIndex)
-  })
-}
-
-function itemInStage(item: CarouselItemContext, index: number) {
-  const _items = unref(items)
-  const itemCount = _items.length
-  if (itemCount === 0 || !item.states.inStage) return false
-  const nextItemIndex = index + 1
-  const prevItemIndex = index - 1
-  const lastItemIndex = itemCount - 1
-  const isLastItemActive = _items[lastItemIndex].states.active
-  const isFirstItemActive = _items[0].states.active
-  const isNextItemActive = _items[nextItemIndex]?.states?.active
-  const isPrevItemActive = _items[prevItemIndex]?.states?.active
-
-  if ((index === lastItemIndex && isFirstItemActive) || isNextItemActive) {
-    return 'left'
-  } else if ((index === 0 && isLastItemActive) || isPrevItemActive) {
-    return 'right'
-  }
-  return false
-}
-
-function handleMouseEnter() {
-  hover.value = true
-  if (props.pauseOnHover) {
-    pauseTimer()
-  }
-}
-
-function handleMouseLeave() {
-  hover.value = false
-  startTimer()
-}
-
-function handleButtonEnter(arrow: 'left' | 'right') {
-  if (unref(isVertical)) return
-  items.value.forEach((item, index) => {
-    if (arrow === itemInStage(item, index)) {
-      item.states.hover = true
-    }
-  })
-}
-
-function handleButtonLeave() {
-  if (unref(isVertical)) return
-  items.value.forEach((item) => {
-    item.states.hover = false
-  })
-}
-
-function handleIndicatorClick(index: number) {
-  activeIndex.value = index
-}
-
-function handleIndicatorHover(index: number) {
-  if (props.trigger === 'hover' && index !== activeIndex.value) {
-    activeIndex.value = index
-  }
-}
-
-function prev() {
-  setActiveItem(activeIndex.value - 1)
-}
-
-function next() {
-  setActiveItem(activeIndex.value + 1)
-}
-
-function resetTimer() {
-  pauseTimer()
-  startTimer()
-}
-
-// watch
-watch(
-  () => activeIndex.value,
-  (current, prev) => {
-    resetItemPosition(prev)
-    if (prev > -1) {
-      emit('change', current, prev)
-    }
-  }
-)
-watch(
-  () => props.autoplay,
-  (autoplay) => {
-    autoplay ? startTimer() : pauseTimer()
-  }
-)
-watch(
-  () => props.loop,
-  () => {
-    setActiveItem(activeIndex.value)
-  }
-)
-
-watch(
-  () => props.interval,
-  () => {
-    resetTimer()
-  }
-)
-
-watch(
-  () => items.value,
-  () => {
-    if (items.value.length > 0) setActiveItem(props.initialIndex)
-  }
-)
-
-const resizeObserver = shallowRef<ReturnType<typeof useResizeObserver>>()
-// lifecycle
-onMounted(() => {
-  resizeObserver.value = useResizeObserver(root.value, () => {
-    resetItemPosition()
-  })
-  startTimer()
-})
-
-onBeforeUnmount(() => {
-  pauseTimer()
-  if (root.value && resizeObserver.value) resizeObserver.value.stop()
-})
-
-// provide
-provide(carouselContextKey, {
-  root,
-  isCardType,
-  isVertical,
-  items,
-  loop: props.loop,
-  addItem,
-  removeItem,
-  setActiveItem,
-})
-
 defineExpose({
   /** @description manually switch slide */
   setActiveItem,
diff --git a/packages/components/carousel/src/instance.ts b/packages/components/carousel/src/instance.ts
new file mode 100644
index 00000000000000..e935041c3a69bf
--- /dev/null
+++ b/packages/components/carousel/src/instance.ts
@@ -0,0 +1,3 @@
+import type Carousel from './carousel.vue'
+
+export type CarouselInstance = InstanceType<typeof Carousel>
diff --git a/packages/components/carousel/src/use-carousel.ts b/packages/components/carousel/src/use-carousel.ts
new file mode 100644
index 00000000000000..1b28bbaa88072c
--- /dev/null
+++ b/packages/components/carousel/src/use-carousel.ts
@@ -0,0 +1,276 @@
+import {
+  computed,
+  getCurrentInstance,
+  onBeforeUnmount,
+  onMounted,
+  provide,
+  ref,
+  shallowRef,
+  unref,
+  watch,
+} from 'vue'
+import { throttle } from 'lodash-unified'
+import { useResizeObserver } from '@vueuse/core'
+import { debugWarn, isString } from '@element-plus/utils'
+import { carouselContextKey } from '@element-plus/tokens'
+import { useOrderedChildren } from '@element-plus/hooks'
+
+import type { SetupContext } from 'vue'
+import type { CarouselItemContext } from '@element-plus/tokens'
+import type { CarouselEmits, CarouselProps } from './carousel'
+
+const THROTTLE_TIME = 300
+
+export const useCarousel = (
+  props: CarouselProps,
+  emit: SetupContext<CarouselEmits>['emit'],
+  componentName: string
+) => {
+  const {
+    children: items,
+    addChild: addItem,
+    removeChild: removeItem,
+  } = useOrderedChildren<CarouselItemContext>(
+    getCurrentInstance()!,
+    'ElCarouselItem'
+  )
+
+  // refs
+  const activeIndex = ref(-1)
+  const timer = ref<ReturnType<typeof setInterval> | null>(null)
+  const hover = ref(false)
+  const root = ref<HTMLDivElement>()
+
+  // computed
+  const arrowDisplay = computed(
+    () => props.arrow !== 'never' && !unref(isVertical)
+  )
+
+  const hasLabel = computed(() => {
+    return items.value.some((item) => item.props.label.toString().length > 0)
+  })
+
+  const isCardType = computed(() => props.type === 'card')
+  const isVertical = computed(() => props.direction === 'vertical')
+
+  // methods
+  const throttledArrowClick = throttle(
+    (index: number) => {
+      setActiveItem(index)
+    },
+    THROTTLE_TIME,
+    { trailing: true }
+  )
+
+  const throttledIndicatorHover = throttle((index: number) => {
+    handleIndicatorHover(index)
+  }, THROTTLE_TIME)
+
+  function pauseTimer() {
+    if (timer.value) {
+      clearInterval(timer.value)
+      timer.value = null
+    }
+  }
+
+  function startTimer() {
+    if (props.interval <= 0 || !props.autoplay || timer.value) return
+    timer.value = setInterval(() => playSlides(), props.interval)
+  }
+
+  const playSlides = () => {
+    if (activeIndex.value < items.value.length - 1) {
+      activeIndex.value = activeIndex.value + 1
+    } else if (props.loop) {
+      activeIndex.value = 0
+    }
+  }
+
+  function setActiveItem(index: number | string) {
+    if (isString(index)) {
+      const filteredItems = items.value.filter(
+        (item) => item.props.name === index
+      )
+      if (filteredItems.length > 0) {
+        index = items.value.indexOf(filteredItems[0])
+      }
+    }
+    index = Number(index)
+    if (Number.isNaN(index) || index !== Math.floor(index)) {
+      debugWarn(componentName, 'index must be integer.')
+      return
+    }
+    const itemCount = items.value.length
+    const oldIndex = activeIndex.value
+    if (index < 0) {
+      activeIndex.value = props.loop ? itemCount - 1 : 0
+    } else if (index >= itemCount) {
+      activeIndex.value = props.loop ? 0 : itemCount - 1
+    } else {
+      activeIndex.value = index
+    }
+    if (oldIndex === activeIndex.value) {
+      resetItemPosition(oldIndex)
+    }
+    resetTimer()
+  }
+
+  function resetItemPosition(oldIndex?: number) {
+    items.value.forEach((item, index) => {
+      item.translateItem(index, activeIndex.value, oldIndex)
+    })
+  }
+
+  function itemInStage(item: CarouselItemContext, index: number) {
+    const _items = unref(items)
+    const itemCount = _items.length
+    if (itemCount === 0 || !item.states.inStage) return false
+    const nextItemIndex = index + 1
+    const prevItemIndex = index - 1
+    const lastItemIndex = itemCount - 1
+    const isLastItemActive = _items[lastItemIndex].states.active
+    const isFirstItemActive = _items[0].states.active
+    const isNextItemActive = _items[nextItemIndex]?.states?.active
+    const isPrevItemActive = _items[prevItemIndex]?.states?.active
+
+    if ((index === lastItemIndex && isFirstItemActive) || isNextItemActive) {
+      return 'left'
+    } else if ((index === 0 && isLastItemActive) || isPrevItemActive) {
+      return 'right'
+    }
+    return false
+  }
+
+  function handleMouseEnter() {
+    hover.value = true
+    if (props.pauseOnHover) {
+      pauseTimer()
+    }
+  }
+
+  function handleMouseLeave() {
+    hover.value = false
+    startTimer()
+  }
+
+  function handleButtonEnter(arrow: 'left' | 'right') {
+    if (unref(isVertical)) return
+    items.value.forEach((item, index) => {
+      if (arrow === itemInStage(item, index)) {
+        item.states.hover = true
+      }
+    })
+  }
+
+  function handleButtonLeave() {
+    if (unref(isVertical)) return
+    items.value.forEach((item) => {
+      item.states.hover = false
+    })
+  }
+
+  function handleIndicatorClick(index: number) {
+    activeIndex.value = index
+  }
+
+  function handleIndicatorHover(index: number) {
+    if (props.trigger === 'hover' && index !== activeIndex.value) {
+      activeIndex.value = index
+    }
+  }
+
+  function prev() {
+    setActiveItem(activeIndex.value - 1)
+  }
+
+  function next() {
+    setActiveItem(activeIndex.value + 1)
+  }
+
+  function resetTimer() {
+    pauseTimer()
+    startTimer()
+  }
+
+  // watch
+  watch(
+    () => activeIndex.value,
+    (current, prev) => {
+      resetItemPosition(prev)
+      if (prev > -1) {
+        emit('change', current, prev)
+      }
+    }
+  )
+  watch(
+    () => props.autoplay,
+    (autoplay) => {
+      autoplay ? startTimer() : pauseTimer()
+    }
+  )
+  watch(
+    () => props.loop,
+    () => {
+      setActiveItem(activeIndex.value)
+    }
+  )
+
+  watch(
+    () => props.interval,
+    () => {
+      resetTimer()
+    }
+  )
+
+  watch(
+    () => items.value,
+    () => {
+      if (items.value.length > 0) setActiveItem(props.initialIndex)
+    }
+  )
+
+  const resizeObserver = shallowRef<ReturnType<typeof useResizeObserver>>()
+  // lifecycle
+  onMounted(() => {
+    resizeObserver.value = useResizeObserver(root.value, () => {
+      resetItemPosition()
+    })
+    startTimer()
+  })
+
+  onBeforeUnmount(() => {
+    pauseTimer()
+    if (root.value && resizeObserver.value) resizeObserver.value.stop()
+  })
+
+  // provide
+  provide(carouselContextKey, {
+    root,
+    isCardType,
+    isVertical,
+    items,
+    loop: props.loop,
+    addItem,
+    removeItem,
+    setActiveItem,
+  })
+
+  return {
+    activeIndex,
+    arrowDisplay,
+    hasLabel,
+    hover,
+    isCardType,
+    items,
+    handleButtonEnter,
+    handleButtonLeave,
+    handleIndicatorClick,
+    handleMouseEnter,
+    handleMouseLeave,
+    setActiveItem,
+    prev,
+    next,
+    throttledArrowClick,
+    throttledIndicatorHover,
+  }
+}