(精华)2020年7月17日 vue mixins的使用

以echarts折线图为例

<template>
  <div :class="className" :style="{height:height,width:width}" />
</template>

<script>
import echarts from 'echarts'
require('echarts/theme/macarons') // echarts theme
import resize from './mixins/resize'

export default {
  mixins: [resize],
  props: {
    className: {
      type: String,
      default: 'chart'
    },
    width: {
      type: String,
      default: '100%'
    },
    height: {
      type: String,
      default: '350px'
    },
    autoResize: {
      type: Boolean,
      default: true
    },
    chartData: {
      type: Object,
      required: true
    }
  },
  data() {
    return {
      chart: null
    }
  },
  watch: {
    chartData: {
      deep: true,
      handler(val) {
        this.setOptions(val)
      }
    }
  },
  mounted() {
    this.$nextTick(() => {
      this.initChart()
    })
  },
  beforeDestroy() {
    if (!this.chart) {
      return
    }
    this.chart.dispose()
    this.chart = null
  },
  methods: {
    initChart() {
      this.chart = echarts.init(this.$el, 'macarons')
      this.setOptions(this.chartData)
    },
    setOptions({ expectedData, actualData } = {}) {
      this.chart.setOption({
        xAxis: {
          data: ['Mon', 'Tue', 'Wed', 'Thu', 'Fri', 'Sat', 'Sun'],
          boundaryGap: false,
          axisTick: {
            show: false
          }
        },
        grid: {
          left: 10,
          right: 10,
          bottom: 20,
          top: 30,
          containLabel: true
        },
        tooltip: {
          trigger: 'axis',
          axisPointer: {
            type: 'cross'
          },
          padding: [5, 10]
        },
        yAxis: {
          axisTick: {
            show: false
          }
        },
        legend: {
          data: ['expected', 'actual']
        },
        series: [{
          name: 'expected', itemStyle: {
            normal: {
              color: '#FF005A',
              lineStyle: {
                color: '#FF005A',
                width: 2
              }
            }
          },
          smooth: true,
          type: 'line',
          data: expectedData,
          animationDuration: 2800,
          animationEasing: 'cubicInOut'
        },
        {
          name: 'actual',
          smooth: true,
          type: 'line',
          itemStyle: {
            normal: {
              color: '#3888fa',
              lineStyle: {
                color: '#3888fa',
                width: 2
              },
              areaStyle: {
                color: '#f3f8ff'
              }
            }
          },
          data: actualData,
          animationDuration: 2800,
          animationEasing: 'quadraticOut'
        }]
      })
    }
  }
}
</script>

父组件

<line-chart :chart-data="lineChartData" />
const lineChartData = {
  newVisitis: {
    expectedData: [100, 120, 161, 134, 105, 160, 165],
    actualData: [120, 82, 91, 154, 162, 140, 145]
  },
  messages: {
    expectedData: [200, 192, 120, 144, 160, 130, 140],
    actualData: [180, 160, 151, 106, 145, 150, 130]
  },
  purchases: {
    expectedData: [80, 100, 121, 104, 105, 90, 100],
    actualData: [120, 90, 100, 138, 142, 130, 130]
  },
  shoppings: {
    expectedData: [130, 140, 141, 142, 145, 150, 160],
    actualData: [120, 82, 91, 154, 162, 140, 130]
  }
}

resize.js

import { debounce } from '@/utils'

export default {
  data() {
    return {
      $_sidebarElm: null,
      $_resizeHandler: null
    }
  },
  mounted() {
    this.$_resizeHandler = debounce(() => {
      if (this.chart) {
        this.chart.resize()
      }
    }, 100)
    this.$_initResizeEvent()
    this.$_initSidebarResizeEvent()
  },
  beforeDestroy() {
    this.$_destroyResizeEvent()
    this.$_destroySidebarResizeEvent()
  },
  // to fixed bug when cached by keep-alive
  // https://github.com/PanJiaChen/vue-element-admin/issues/2116
  activated() {
    this.$_initResizeEvent()
    this.$_initSidebarResizeEvent()
  },
  deactivated() {
    this.$_destroyResizeEvent()
    this.$_destroySidebarResizeEvent()
  },
  methods: {
    // use $_ for mixins properties
    // https://vuejs.org/v2/style-guide/index.html#Private-property-names-essential
    $_initResizeEvent() {
      window.addEventListener('resize', this.$_resizeHandler)
    },
    $_destroyResizeEvent() {
      window.removeEventListener('resize', this.$_resizeHandler)
    },
    $_sidebarResizeHandler(e) {
      if (e.propertyName === 'width') {
        this.$_resizeHandler()
      }
    },
    $_initSidebarResizeEvent() {
      this.$_sidebarElm = document.getElementsByClassName('sidebar-container')[0]
      this.$_sidebarElm && this.$_sidebarElm.addEventListener('transitionend', this.$_sidebarResizeHandler)
    },
    $_destroySidebarResizeEvent() {
      this.$_sidebarElm && this.$_sidebarElm.removeEventListener('transitionend', this.$_sidebarResizeHandler)
    }
  }
}

debounce.js

export function debounce(func, wait, immediate) {
  let timeout, args, context, timestamp, result

  const later = function() {
    // 据上一次触发时间间隔
    const last = +new Date() - timestamp

    // 上次被包装函数被调用时间间隔 last 小于设定时间间隔 wait
    if (last < wait && last > 0) {
      timeout = setTimeout(later, wait - last)
    } else {
      timeout = null
      // 如果设定为immediate===true，因为开始边界已经调用过了此处无需调用
      if (!immediate) {
        result = func.apply(context, args)
        if (!timeout) context = args = null
      }
    }
  }

  return function(...args) {
    context = this
    timestamp = +new Date()
    const callNow = immediate && !timeout
    // 如果延时不存在，重新设定延时
    if (!timeout) timeout = setTimeout(later, wait)
    if (callNow) {
      result = func.apply(context, args)
      context = args = null
    }

    return result
  }
}