源码

clickoutside 主要代码

import Vue from 'vue';

/* istanbul ignore next */
export const on = (function() {
  if (!isServer && document.addEventListener) {
    return function(element, event, handler) {
      if (element && event && handler) {
        element.addEventListener(event, handler, false);
      }
    };
  } else {
    return function(element, event, handler) {
      if (element && event && handler) {
        element.attachEvent('on' + event, handler);
      }
    };
  }
})();

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

let startClick;
let seed = 0;
// 在mousedown的时候保存mousedown的元素
// !Vue.prototype.$isServer 开发的时候为false，具体没看原因
!Vue.prototype.$isServer && on(document, 'mousedown', e => (startClick = e));
// doucument.addEventListener('mousedown', e => (startClick = e), false)
// 在mouseup 的时候把list存储的DOM节点挨个执行添加的方法，并传入 mousedown 和 mouseup 的 DOM
!Vue.prototype.$isServer && on(document, 'mouseup', e => {
  nodeList.forEach(node => node[ctx].documentHandler(e, startClick));
});
/*
  document.addEventListener("mouseup",  e => {
  nodeList.forEach(node => node[ctx].documentHandler(e, startClick));
  } , fasle)
*/
// 闭包的运用 el 是使用指令的元素
function createDocumentHandler(el, binding, vnode) {
  return function(mouseup = {}, mousedown = {}) {
    if (!vnode ||
      !vnode.context ||
      !mouseup.target ||
      !mousedown.target ||
      el.contains(mouseup.target) ||  // 在元素内部的mouseup
      el.contains(mousedown.target) || // 在元素内部的mousedown
      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-element-clickoutside="handleClose">
 * ```
 */
export default {
  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;
  },

  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];
  }
};