otb-module/src/utils/directives.js

otb-module是基于现有的element-ui库进行的二次封装，简化组件的各自用法，将所有基础组件归纳于一个表单中， 集成表单组件，另还有增删改查的CRUD组件、预览图片/PDF的preview组件、上传文件的upload组件、分页组件与导出组件等等。 引入组件后以数据驱动组件从而加载Dom，让开发变得更简单，让代码更易维护。

// 绑定班主任按钮权限
import {go} from "otb-module/src/utils/tool"

export default {
  install(Vue) {
    // 跳转
    Vue.directive("go", {
      bind(el, binding) {
        let handleClick = (e) => {
          if (el.contains(e.target)) {
            let code, params
            if (binding.value instanceof Array) {
              code = binding.value[0]
              params = binding.value[1] || ""
            } else {
              code = binding.value
            }
            go(code, params)
          }
        }

        el["__clickHandle__"] = handleClick
        document.addEventListener("click", handleClick)
      },

      unbind(el) {
        document.removeEventListener("click", el["__clickHandle__"])
        delete el["__clickHandle__"]
      }
    })

    // 避免按钮重复点击
    Vue.directive("btnLoading", {
      inserted(el, binding) {
        el.addEventListener("click", () => {
          el.classList.add("is-loading")

          let dom = document.createElement("i")
          dom.className = "el-icon-loading"
          el.appendChild(dom)

          setTimeout(() => {
            el.classList.remove("is-loading")
            el.removeChild(dom)
          }, binding.value || 2000)
        })
      }
    })

    // 弹框可拖拽
    Vue.directive('dialogDrag', {
      bind(el, binding, vnode) {
        const dialogHeaderEl = el.querySelector('.el-dialog__header')
        const dragDom = el.querySelector('.el-dialog')
        dialogHeaderEl.style.cssText += ';cursor:move;'
        dragDom.style.cssText += ';top:0px;'

        // 获取原有属性 ie dom元素.currentStyle 火狐谷歌 window.getComputedStyle(dom元素, null)
        const getStyle = (function () {
          if (window.document.currentStyle) {
            return (dom, attr) => dom.currentStyle[attr]
          } else {
            return (dom, attr) => getComputedStyle(dom, false)[attr]
          }
        })()

        dialogHeaderEl.onmousedown = e => {
          // 鼠标按下，计算当前元素距离可视区的距离
          const disX = e.clientX - dialogHeaderEl.offsetLeft
          const disY = e.clientY - dialogHeaderEl.offsetTop

          const dragDomWidth = dragDom.offsetWidth
          const dragDomHeight = dragDom.offsetHeight

          const screenWidth = document.body.clientWidth
          const screenHeight = document.body.clientHeight

          const minDragDomLeft = dragDom.offsetLeft
          const maxDragDomLeft = screenWidth - dragDom.offsetLeft - dragDomWidth

          const minDragDomTop = dragDom.offsetTop
          const maxDragDomTop = screenHeight - dragDom.offsetTop - dragDomHeight

          // 获取到的值带px 正则匹配替换
          let styL = getStyle(dragDom, 'left')
          let styT = getStyle(dragDom, 'top')
          if (styL.includes('%')) {
            // eslint-disable-next-line no-useless-escape
            styL = +document.body.clientWidth * (+styL.replace(/\%/g, '') / 100)
            // eslint-disable-next-line no-useless-escape
            styT = +document.body.clientHeight * (+styT.replace(/\%/g, '') / 100)
          } else {
            styL = +styL.replace('px', '')
            styT = +styT.replace('px', '')
          }

          document.onmousemove = function (e) {
            // 通过事件委托，计算移动的距离
            let left = e.clientX - disX
            let top = e.clientY - disY

            // 边界处理
            if (-(left) > minDragDomLeft) {
              left = -minDragDomLeft
            } else if (left > maxDragDomLeft) {
              left = maxDragDomLeft
            }

            if (-(top) > minDragDomTop) {
              top = -minDragDomTop
            } else if (top > maxDragDomTop) {
              top = maxDragDomTop
            }

            if (top < -disY) {
              top = 0
            }
            // 移动当前元素
            dragDom.style.cssText += `;left:${left + styL}px;top:${top + styT}px;`

            // emit onDrag event
            vnode.child.$emit('drag-dialog')
          }

          document.onmouseup = function () {
            document.onmousemove = null
            document.onmouseup = null
          }
        }
      }
    });
  }
}