电商图片显示组件和SKU组件的封装

一、电商图片显示组件

<script setup>
import { ref, watch } from 'vue'
import { useMouseInElement } from '@vueuse/core'

// 图片列表
const imageList = [
  'https://yanxuan-item.nosdn.127.net/d917c92e663c5ed0bb577c7ded73e4ec.png',
  'https://yanxuan-item.nosdn.127.net/e801b9572f0b0c02a52952b01adab967.jpg',
  'https://yanxuan-item.nosdn.127.net/b52c447ad472d51adbdde1a83f550ac2.jpg',
  'https://yanxuan-item.nosdn.127.net/f93243224dc37674dfca5874fe089c60.jpg',
  'https://yanxuan-item.nosdn.127.net/f881cfe7de9a576aaeea6ee0d1d24823.jpg',
]

// 1.小图切换大图显示
const activeIndex = ref(0)

const enterhandler = (i) => {
  activeIndex.value = i
}

// 2. 获取鼠标相对位置
const target = ref(null)
const { elementX, elementY, isOutside } = useMouseInElement(target)

// 3. 控制滑块跟随鼠标移动（监听elementX/Y变化，一旦变化 重新设置left/top）
const left = ref(0)
const top = ref(0)

const positionX = ref(0)
const positionY = ref(0)
watch([elementX, elementY, isOutside], () => {
  // 如果鼠标没有移入到盒子里面 直接不执行后面的逻辑
  if (isOutside.value) return

  // 有效范围内控制滑块距离
  // 横向
  if (elementX.value > 100 && elementX.value < 300) {
    left.value = elementX.value - 100
  }
  // 纵向
  if (elementY.value > 100 && elementY.value < 300) {
    top.value = elementY.value - 100
  }

  // 处理边界
  if (elementX.value > 300) {
    left.value = 200
  }
  if (elementX.value < 100) {
    left.value = 0
  }

  if (elementY.value > 300) {
    top.value = 200
  }
  if (elementY.value < 100) {
    top.value = 0
  }

  // 控制大图的显示
  positionX.value = -left.value * 2
  positionY.value = -top.value * 2
})
</script>

<template>
  <div class="goods-image">
    <!-- 左侧大图-->
    <div class="middle" ref="target">
      <img :src="imageList[activeIndex]" alt="" />
      <!-- 蒙层小滑块 -->
      <div
        class="layer"
        v-show="!isOutside"
        :style="{ left: `${left}px`, top: `${top}px` }"
      ></div>
    </div>
    <!-- 小图列表 -->
    <ul class="small">
      <li
        v-for="(img, i) in imageList"
        :key="i"
        @mouseenter="enterhandler(i)"
        :class="{ active: i === activeIndex }"
      >
        <img :src="img" alt="" />
      </li>
    </ul>
    <!-- 放大镜大图 -->
    <div
      class="large"
      :style="[
        {
          backgroundImage: `url(${imageList[0]})`,
          backgroundPositionX: `${positionX}px`,
          backgroundPositionY: `${positionY}px`,
        },
      ]"
      v-show="!isOutside"
    ></div>
  </div>
</template>

<style scoped lang="scss">
.goods-image {
  width: 480px;
  height: 400px;
  position: relative;
  display: flex;

  .middle {
    width: 400px;
    height: 400px;
    background: #f5f5f5;
  }

  .large {
    position: absolute;
    top: 0;
    left: 412px;
    width: 400px;
    height: 400px;
    z-index: 500;
    box-shadow: 0 0 10px rgba(0, 0, 0, 0.1);
    background-repeat: no-repeat;
    // 背景图:盒子的大小 = 2:1  将来控制背景图的移动来实现放大的效果查看 background-position
    background-size: 800px 800px;
    background-color: #f8f8f8;
  }

  .layer {
    width: 200px;
    height: 200px;
    background: rgba(0, 0, 0, 0.2);
    // 绝对定位 然后跟随咱们鼠标控制left和top属性就可以让滑块移动起来
    left: 0;
    top: 0;
    position: absolute;
  }

  .small {
    width: 80px;

    li {
      width: 68px;
      height: 68px;
      margin-left: 12px;
      margin-bottom: 15px;
      cursor: pointer;

      &:hover,
      &.active {
        border: 2px solid $xtxColor;
      }
    }
  }
}
</style>

二、SKU 组件

此组件需要用到计算数组子集的算法

power-set.js

export default function bwPowerSet(originalSet) {
  const subSets = []

  // We will have 2^n possible combinations (where n is a length of original set).
  // It is because for every element of original set we will decide whether to include
  // it or not (2 options for each set element).
  const numberOfCombinations = 2 ** originalSet.length

  // Each number in binary representation in a range from 0 to 2^n does exactly what we need:
  // it shows by its bits (0 or 1) whether to include related element from the set or not.
  // For example, for the set {1, 2, 3} the binary number of 0b010 would mean that we need to
  // include only "2" to the current set.
  for (
    let combinationIndex = 0;
    combinationIndex < numberOfCombinations;
    combinationIndex += 1
  ) {
    const subSet = []

    for (
      let setElementIndex = 0;
      setElementIndex < originalSet.length;
      setElementIndex += 1
    ) {
      // Decide whether we need to include current element into the subset or not.
      if (combinationIndex & (1 << setElementIndex)) {
        subSet.push(originalSet[setElementIndex])
      }
    }

    // Add current subset to the list of all subsets.
    subSets.push(subSet)
  }

  return subSets
}

<template>
  <div class="goods-sku">
    <dl v-for="item in goods.specs" :key="item.id">
      <dt>{{ item.name }}</dt>
      <dd>
        <template v-for="val in item.values" :key="val.name">
          <img
            :class="{ selected: val.selected, disabled: val.disabled }"
            @click="clickSpecs(item, val)"
            v-if="val.picture"
            :src="val.picture"
          />
          <span
            :class="{ selected: val.selected, disabled: val.disabled }"
            @click="clickSpecs(item, val)"
            v-else
            >{{ val.name }}</span
          >
        </template>
      </dd>
    </dl>
  </div>
</template>
<script>
import { watchEffect } from 'vue'
import getPowerSet from './power-set'
const spliter = '★'
// 根据skus数据得到路径字典对象
const getPathMap = (skus) => {
  const pathMap = {}
  if (skus && skus.length > 0) {
    skus.forEach((sku) => {
      // 1. 过滤出有库存有效的sku
      if (sku.inventory) {
        // 2. 得到sku属性值数组
        const specs = sku.specs.map((spec) => spec.valueName)
        // 3. 得到sku属性值数组的子集
        const powerSet = getPowerSet(specs)
        // 4. 设置给路径字典对象
        powerSet.forEach((set) => {
          const key = set.join(spliter)
          // 如果没有就先初始化一个空数组
          if (!pathMap[key]) {
            pathMap[key] = []
          }
          pathMap[key].push(sku.id)
        })
      }
    })
  }
  return pathMap
}

// 初始化禁用状态
function initDisabledStatus(specs, pathMap) {
  if (specs && specs.length > 0) {
    specs.forEach((spec) => {
      spec.values.forEach((val) => {
        // 设置禁用状态
        val.disabled = !pathMap[val.name]
      })
    })
  }
}

// 得到当前选中规格集合
const getSelectedArr = (specs) => {
  const selectedArr = []
  specs.forEach((spec, index) => {
    const selectedVal = spec.values.find((val) => val.selected)
    if (selectedVal) {
      selectedArr[index] = selectedVal.name
    } else {
      selectedArr[index] = undefined
    }
  })
  return selectedArr
}

// 更新按钮的禁用状态
const updateDisabledStatus = (specs, pathMap) => {
  // 遍历每一种规格
  specs.forEach((item, i) => {
    // 拿到当前选择的项目
    const selectedArr = getSelectedArr(specs)
    // 遍历每一个按钮
    item.values.forEach((val) => {
      if (!val.selected) {
        selectedArr[i] = val.name
        // 去掉undefined之后组合成key
        const key = selectedArr.filter((value) => value).join(spliter)
        val.disabled = !pathMap[key]
      }
    })
  })
}

export default {
  name: 'XtxGoodSku',
  props: {
    // specs:所有的规格信息  skus:所有的sku组合
    goods: {
      type: Object,
      default: () => ({ specs: [], skus: [] }),
    },
  },
  emits: ['change'],
  setup(props, { emit }) {
    let pathMap = {}
    watchEffect(() => {
      // 得到所有字典集合
      pathMap = getPathMap(props.goods.skus)
      // 组件初始化的时候更新禁用状态
      initDisabledStatus(props.goods.specs, pathMap)
    })

    const clickSpecs = (item, val) => {
      if (val.disabled) return false
      // 选中与取消选中逻辑
      if (val.selected) {
        val.selected = false
      } else {
        item.values.forEach((bv) => {
          bv.selected = false
        })
        val.selected = true
      }
      // 点击之后再次更新选中状态
      updateDisabledStatus(props.goods.specs, pathMap)
      // 把选择的sku信息传出去给父组件
      // 触发change事件将sku数据传递出去
      const selectedArr = getSelectedArr(props.goods.specs).filter(
        (value) => value
      )
      // 如果选中得规格数量和传入得规格总数相等则传出完整信息(都选择了)
      // 否则传出空对象
      if (selectedArr.length === props.goods.specs.length) {
        // 从路径字典中得到skuId
        const skuId = pathMap[selectedArr.join(spliter)][0]
        const sku = props.goods.skus.find((sku) => sku.id === skuId)
        // 传递数据给父组件
        emit('change', {
          skuId: sku.id,
          price: sku.price,
          oldPrice: sku.oldPrice,
          inventory: sku.inventory,
          specsText: sku.specs
            .reduce((p, n) => `${p} ${n.name}：${n.valueName}`, '')
            .trim(),
        })
      } else {
        emit('change', {})
      }
    }
    return { clickSpecs }
  },
}
</script>

<style scoped lang="scss">
@mixin sku-state-mixin {
  border: 1px solid #e4e4e4;
  margin-right: 10px;
  cursor: pointer;

  &.selected {
    border-color: $xtxColor;
  }

  &.disabled {
    opacity: 0.6;
    border-style: dashed;
    cursor: not-allowed;
  }
}

.goods-sku {
  padding-left: 10px;
  padding-top: 20px;

  dl {
    display: flex;
    padding-bottom: 20px;
    align-items: center;

    dt {
      width: 50px;
      color: #999;
    }

    dd {
      flex: 1;
      color: #666;

      > img {
        width: 50px;
        height: 50px;
        margin-bottom: 4px;
        @include sku-state-mixin;
      }

      > span {
        display: inline-block;
        height: 30px;
        line-height: 28px;
        padding: 0 20px;
        margin-bottom: 4px;
        @include sku-state-mixin;
      }
    }
  }
}
</style>