vue 自定义指令心得

//各个快捷键对应的code
const hotKeyList = {
  "S": 83,
  "O": 79,
  "Q": 81,
  "R": 82,
  ‘ESC‘: 27,
};

function bindEvent(e, el, arg) {
  if(!el || !arg){
    return
  }
  if (el.displayFlag) {
    // console.log(el) 监听组合快捷键ctrl
    let keyCode = e.keyCode || e.which || e.charCode;
    let ctrlKey = e.ctrlKey || e.metaKey;
    if (arg === ‘ESC‘ && keyCode === hotKeyList[arg]) {
      el.click()
      e.preventDefault();
      e.returnValue = false;
      return false;
    } else {
      if (ctrlKey && keyCode === hotKeyList[arg]) {
        el.click()
        e.preventDefault();
        e.returnValue = false;
        return false;
      }

    }

  }

}

// 递归检测触发的按钮是否会显示
function checkDisplay(el) {

  if (el.localName === "body") {
    return true
  }
  if (el.style.display === ‘none‘) {
    return false
  } else {
    if (el.style.display === ‘block‘) {
      return true
    } else {
      return checkDisplay(el.parentNode)  //递归一定要加retur
    }
  }
}

export default {
  name: "shortcutKey",
  inserted() {
    console.log(‘inserted‘)
//最好不要用bind，因为bind的el.parentNode是取不到的,用insert或是update都可以
  },

  update(el, binding) {

    // console.log(‘update‘)

    if (hotKeyList[binding.arg]) {
      setTimeout(() => {
        el.displayFlag = checkDisplay(el)
        if (!el.displayFlag) {
          window.removeEventListener(‘keydown‘, e => bindEvent(e, el, binding.arg))
        } else {
          window.addEventListener(‘keydown‘, e => bindEvent(e, el, binding.arg))
        }

      }, 300)

    }

  },

  unbind() {
 //解绑事件，应该是有问题的，因为自定义指令定义的变量不是局部的，第二个指令会覆盖调之前定义的
    window.removeEventListener(‘keydown‘, bindEvent)

  }
};

import Vue from "vue";

const isServer = Vue.prototype.$isServer;
const on = (function () {
  if (!isServer && document.addEventListener) {
    return function (element, event, handler) {
      if (element && event && handler) {
        element.addEventListener(event, handler, false);
      }
    };
  }
  return function (element, event, handler) {
    if (element && event && handler) {
      element.attachEvent("on" + event, handler);
    }
  };
})();

const nodeList = [];
const ctx = "@@clickoutsideContext";

let startClick;
let seed = 0;

!Vue.prototype.$isServer && on(document, "mousedown", e => (startClick = e));

!Vue.prototype.$isServer &&
  on(document, "mouseup", e => {
    nodeList.forEach(node => node[ctx].documentHandler(e, startClick));
  });

function createDocumentHandler(el, binding, vnode) {
  return function (mouseup = {}, mousedown = {}) {
    if (
      !vnode ||
      !vnode.context ||
      !mouseup.target ||
      !mousedown.target ||
      el.contains(mouseup.target) ||
      el.contains(mousedown.target) ||
      el === mouseup.target ||
      (vnode.context.popperElm &&
        (vnode.context.popperElm.contains(mouseup.target) ||
          vnode.context.popperElm.contains(mousedown.target)))
    )
      return;

    if (
      binding.expression &&
      el[ctx].methodName &&
      vnode.context[el[ctx].methodName]
    ) {
      vnode.context[el[ctx].methodName]();
    } else {
      el[ctx].bindingFn && el[ctx].bindingFn();
    }
  };
}

/**
 * v-clickoutside
 * @desc 点击元素外面才会触发的事件
 * @example
 * ```vue
 * <div v-clickoutside="handleClose">
 * ```
 */
export default {
  name: "clickoutside",
  bind(el, binding, vnode) {
    nodeList.push(el);
    const id = seed++;
    el[ctx] = {
      id,
      documentHandler: createDocumentHandler(el, binding, vnode),
      methodName: binding.expression,
      bindingFn: binding.value
    };

  },

  update(el, binding, vnode) {

    el[ctx].documentHandler = createDocumentHandler(el, binding, vnode);
    el[ctx].methodName = binding.expression;
    el[ctx].bindingFn = binding.value;

    // 判断指令中是否绑定了函数
    if (binding.expression) {
      // 如果绑定了函数 则调用那个函数，此处binding.value就是handleClose方法
      binding.value(startClick);
    }

  },

  unbind(el) {
    let len = nodeList.length;

    for (let i = 0; i < len; i++) {
      if (nodeList[i][ctx].id === el[ctx].id) {
        nodeList.splice(i, 1);
        break;
      }
    }
    delete el[ctx];
  }
};

原文地址：https://www.cnblogs.com/xmhu/p/10115413.html