浅析vue中的自定义指令使用

const clickOutside = {
  bind: function(el, binding, vnode) {
    el.clickOutsideEvent = function(event) {
      if (!(el === event.target || el.contains(event.target))) {
        vnode.context[binding.expression](event)
      }
    }
    document.body.addEventListener('click', el.clickOutsideEvent)
  },
  unbind: function(el) {
    document.body.removeEventListener('click', el.clickOutsideEvent)
  }
}

export default clickOutside

const copy = {
  bind: function(el, binding) {
    el.addEventListener('click', function() {
      const textToCopy = binding.value
      const input = document.createElement('input')
      input.setAttribute('value', textToCopy)
      document.body.appendChild(input)
      input.select()
      document.execCommand('copy')
      document.body.removeChild(input)
    })
  }
}

export default copy

// 在指令的inserted钩子函数中，定义一个正则表达式，用来匹配表情及特殊字符。
// 在指令的update钩子函数中，判断输入框的值是否发生变化，如果变化了，则使用正则表达式来过滤输入框的值。
// 在指令的unbind钩子函数中，清除事件监听器，避免内存泄漏。
const emoji = {
  inserted: function(el) {
    el.addEventListener('input', function() {
      const reg = /[\uD800-\uDBFF][\uDC00-\uDFFF]|[\uD800-\uDFFF]|[\u200D\uFE0F\uFE00-\uFE0F]/g
      el.value = el.value.replace(reg, '')
    })
  },
  update: function(el) {
    const reg = /[\uD800-\uDBFF][\uDC00-\uDFFF]|[\uD800-\uDFFF]|[\u200D\uFE0F\uFE00-\uFE0F]/g
    el.value = el.value.replace(reg, '')
  },
  unbind: function(el) {
    el.removeEventListener('input')
  }
}

export default emoji

const enterToInput = {
  inserted: function(el) {
    let inputs = el.querySelectorAll('input')
    // 绑定回写事件
    for (var i = 0; i < inputs.length; i++) {
      inputs[i].setAttribute('keyFocusIndex', i)
      inputs[i].addEventListener('keyup', ev => {
        if (ev.keyCode === 13) {
          const targetTo = ev.srcElement.getAttribute('keyFocusTo')
          if (targetTo) {
            this.$refs[targetTo].$el.focus()
          } else {
            var attrIndex = ev.srcElement.getAttribute('keyFocusIndex')
            var ctlI = parseInt(attrIndex)
            inputs = el.querySelectorAll('input')
            if (ctlI < inputs.length - 1) inputs[ctlI + 1].focus()
          }
        }
      })
    }
  }
}

export default enterToInput

import './fit-columns.CSS'

function adjustColumnWidth(table, padding = 0) {
  const colgroup = table.querySelector('colgroup')
  const colDefs = [...colgroup.querySelectorAll('col')]
  colDefs.forEach((col) => {
    const clsName = col.getAttribute('name')
    const clsWidth = col.getAttribute('width')
    if (clsWidth < 200) return
    const cells = [
      ...table.querySelectorAll(`td.${clsName}`),
      ...table.querySelectorAll(`th.${clsName}`)
    ]
    if (cells[0] && cells[0].classList && cells[0].classList.contains && cells[0].classList.contains('leave-alone')) {
      return
    }
    const widthList = cells.map((el) => {
      return el.querySelector('.cell') && el.querySelector('.cell').scrollWidth || 0
    })
    const max = Math.max(...widthList)
    table.querySelectorAll(`col[name=${clsName}]`).forEach((el) => {
      // console.log(222, max + padding)
      el.setAttribute('width', max + padding > 500 ? 500 : max + padding)
    })
  })
}

const fitColumns = {
  update() { },
  bind() { },
  inserted(el, binding) {
    setTimeout(() => {
      adjustColumnWidth(el, binding.value)
    }, 300)
  },
  componentUpdated(el, binding) {
    el.classList.add('r-table')
    setTimeout(() => {
      adjustColumnWidth(el, binding.value)
    }, 300)
  },
  unbind() { }
}

export default fitColumns

.el-table.r-table .cell {
  display: inline-block;
  
  width: auto;
  overflow: auto;
}

.el-table.r-table .el-table__body-wrapper {
  overflow-x: auto;
}

const findEle = (parent, type) => {
  return parent.tagName.toLowerCase() === type
    ? parent
    : parent.querySelector(type)
}

const trigger = (el, type) => {
  const e = document.createEvent('htmlEvents')
  e.initEvent(type, true, true)
  el.dispatchEvent(e)
}

const inputFilter = {
  mounted(el, binding, vnode) {
    const bindV = binding.value
    const regRule = bindV.regRule ? bindV.regRule : /[^\a-zA-Z0-9\u4E00-\u9FA5]+$/g
    const length = bindV.length ? bindV.length : 30
    const $inp = findEle(el, 'input')
    el.$inp = $inp
    $inp.handle = () => {
      const val = $inp.value
      $inp.value = val.replace(regRule, '').substring(0, length)

      trigger($inp, 'input')
    }
    $inp.addEventListener('keyup', $inp.handle)
  },
  unmounted(el) {
    el.$inp.removeEventListener('keyup', el.$inp.handle)
  }
}

export default inputFilter

// 在 bind 钩子函数中绑定了 mousedown、touchstart、click、mouseout、touchend 和 touchcancel 事件。
// 当用户按下鼠标或触摸屏时，我们会启动一个定时器，如果在指定的时间内没有松开鼠标或手指，则执行指令的回调函数。
// 如果用户在指定的时间内松开了鼠标或手指，则取消定时器。
const longpress = {
  bind: function(el, binding) {
    let pressTimer = null
    const duration = binding.value || 500 // 默认长按时间为 500ms

    const start = function(event) {
      if (event.type === 'click' && event.button !== 0) {
        return
      }

      if (pressTimer === null) {
        pressTimer = setTimeout(() => {
          handler()
        }, duration)
      }
    }

    const cancel = function() {
      if (pressTimer !== null) {
        clearTimeout(pressTimer)
        pressTimer = null
      }
    }

    const handler = function() {
      binding.value()
    }

    el.addEventListener('mousedown', start)
    el.addEventListener('touchstart', start)

    el.addEventListener('click', cancel)
    el.addEventListener('mouseout', cancel)
    el.addEventListener('touchend', cancel)
    el.addEventListener('touchcancel', cancel)
  }
}

export default longpress

const resizeHeight = {
  // 绑定时调用
  bind(el, binding) {
    let height = ''
    function isResize() {
      // 可根据需求，调整内部代码，利用 binding.value 返回即可
      const style = document.defaultView.getComputedStyle(el)
      if (height !== style.height) {
        // 此处关键代码，通过此处代码将数据进行返回，从而做到自适应
        binding.value({ height: style.height })
      }
      height = style.height
    }
    // 设置调用函数的延时，间隔过短会消耗过多资源
    el.__vueSetInterval__ = setInterval(isResize, 100)
  },
  unbind(el) {
    clearInterval(el.__vueSetInterval__)
  }
}

export default resizeHeight

const resizeWidth = {
  // 绑定时调用
  bind(el, binding) {
    let width = ''
    function isResize() {
      // 可根据需求，调整内部代码，利用binding.value返回即可
      const style = document.defaultView.getComputedStyle(el)
      if (width !== style.width) {
        // 此处关键代码，通过此处代码将数据进行返回，从而做到自适应
        binding.value({ width: style.width })
      }
      width = style.width
    }
    // 设置调用函数的延时，间隔过短会消耗过多资源
    el.__vueSetInterval__ = setInterval(isResize, 100)
  },
  unbind(el) {
    clearInterval(el.__vueSetInterval__)
  }
}

export default resizeWidth