vue-elementui-admin学习（一）

最近打算仔细的学习一下vue-elemnetui-admin的代码，一是工作需要用到，需要加工一些东西，还有一个就是打算之后好好学习vue，看看源码啥的，所以先从这个框架学起来。
都是一些自己的学习笔记，做一些记录，有不对的地方恳请大家指出，可以一起讨论。
学习了一下permission文件夹下的role.js,用来控制不同用户能够查看菜单的权限

<template>
  <div class="app-container">
    <el-button type="primary" @click="handleAddRole">New Role</el-button>

    <el-table :data="rolesList" style="width: 100%;margin-top:30px;" border>
      <el-table-column align="center" label="Role Key" width="220">
        <template slot-scope="scope">
          {{ scope.row.key }}
        </template>
      </el-table-column>
      <el-table-column align="center" label="Role Name" width="220">
        <template slot-scope="scope">
          {{ scope.row.name }}
        </template>
      </el-table-column>
      <el-table-column align="header-center" label="Description">
        <template slot-scope="scope">
          {{ scope.row.description }}
        </template>
      </el-table-column>
      <el-table-column align="center" label="Operations">
        <template slot-scope="scope">
          <el-button type="primary" size="small" @click="handleEdit(scope)">Edit</el-button>
          <el-button type="danger" size="small" @click="handleDelete(scope)">Delete</el-button>
        </template>
      </el-table-column>
    </el-table>

    <el-dialog :visible.sync="dialogVisible" :title="dialogType==='edit'?'Edit Role':'New Role'">
      <el-form :model="role" label-width="80px" label-position="left">
        <el-form-item label="Name">
          <el-input v-model="role.name" placeholder="Role Name" />
        </el-form-item>
        <el-form-item label="Desc">
          <el-input
            v-model="role.description"
            :autosize="{ minRows: 2, maxRows: 4}"
            type="textarea"
            placeholder="Role Description"
          />
        </el-form-item>
        <el-form-item label="Menus">
          <el-tree
            ref="tree"
            :check-strictly="checkStrictly"
            :data="routesData"
            :props="defaultProps"
            show-checkbox
            node-key="path"
            class="permission-tree"
          />
        </el-form-item>
      </el-form>
      <div style="text-align:right;">
        <el-button type="danger" @click="dialogVisible=false">Cancel</el-button>
        <el-button type="primary" @click="confirmRole">Confirm</el-button>
      </div>
    </el-dialog>
  </div>
</template>

<script>
import path from 'path'
import { deepClone } from '@/utils'
import { getRoutes, getRoles, addRole, deleteRole, updateRole } from '@/api/role'

const defaultRole = {
  key: '',
  name: '',
  description: '',
  routes: []
}

export default {
  data() {
    return {
      role: Object.assign({}, defaultRole),
      routes: [], // 路由列表
      rolesList: [], // 角色列表以及对应的路由信息
      dialogVisible: false,
      dialogType: 'new',
      checkStrictly: false,
      defaultProps: {
        children: 'children',
        label: 'title'
      }
    }
  },
  computed: {
    routesData() {
      return this.routes
    }
  },
  created() {
    // Mock: get all routes and roles list from server
    this.getRoutes() // 获取全部的路由列表
    this.getRoles() // 获取全部角色加里面的权限路由
  },
  methods: {
    async getRoutes() {
      const res = await getRoutes() // res是全部路由列表，由constantRoutes静态路由和asyncRoutes动态路由拼接组成
      this.serviceRoutes = res.data // 将全部路由列表赋值给serviceRoutes
      this.routes = this.generateRoutes(res.data) // 生成树的数据
    },
    async getRoles() {
      const res = await getRoles() // 获取全部的角色信息，以及角色对应的路由信息
      this.rolesList = res.data // 拿到表格数据
    },

    // Reshape the routes structure so that it looks the same as the sidebar
    // 产生最终路由的方法，参数是全部路由信息和‘/'
    generateRoutes(routes, basePath = '/') {
      const res = []

      for (let route of routes) { // 遍历所有路由信息
        // skip some route
        if (route.hidden) { continue } // hidden属性为true，则继续

        const onlyOneShowingChild = this.onlyOneShowingChild(route.children, route) // 得到子路由的完整信息
        // console.log('onlyOneShowingChild', onlyOneShowingChild)
        // 有二级菜单的路由返回的false，进行递归
        // 你可以设置 alwaysShow: true，这样它就会忽略之前定义的规则，一直显示根路由
        // 如果有chilren和生成的信息且不是跟路由
        if (route.children && onlyOneShowingChild && !route.alwaysShow) {
          route = onlyOneShowingChild
        }

        const data = {
          path: path.resolve(basePath, route.path),
          title: route.meta && route.meta.title

        }

        // recursive child routes
        if (route.children) { // 递归路由的子路由
          data.children = this.generateRoutes(route.children, data.path)
        }
        res.push(data) // 放进res中生成路由
      }
      return res
    },
    // 把树的数据routes放进数组里
    generateArr(routes) {
      let data = []
      routes.forEach(route => {
        data.push(route)
        if (route.children) {
          const temp = this.generateArr(route.children)
          if (temp.length > 0) {
            data = [...data, ...temp]
          }
        }
      })
      return data
    },
    handleAddRole() {
      this.role = Object.assign({}, defaultRole)
      if (this.$refs.tree) {
        this.$refs.tree.setCheckedNodes([])
      }
      this.dialogType = 'new'
      this.dialogVisible = true
    },
    // 显示该角色的菜单信息
    handleEdit(scope) {
      this.dialogType = 'edit' // 修改角色权限菜单
      this.dialogVisible = true
      this.checkStrictly = true
      this.role = deepClone(scope.row) // 深度克隆该行的信息，包括路由信息
      console.log('role',this.role)
      this.$nextTick(() => {
        const routes = this.generateRoutes(this.role.routes) // 产生该角色所能查看到的路由信息
        // 设置点开该角色能看到的菜单已被选中，this.generateArr(routes)接收勾选节点数据的数组，
        this.$refs.tree.setCheckedNodes(this.generateArr(routes))
        // set checked state of a node not affects its father and child nodes
        this.checkStrictly = false
        // 在显示复选框的情况下，是否严格的遵循父子不互相关联的做法
      })
    },
    handleDelete({ $index, row }) {
      this.$confirm('Confirm to remove the role?', 'Warning', {
        confirmButtonText: 'Confirm',
        cancelButtonText: 'Cancel',
        type: 'warning'
      })
        .then(async() => {
          await deleteRole(row.key)
          this.rolesList.splice($index, 1)
          this.$message({
            type: 'success',
            message: 'Delete succed!'
          })
        })
        .catch(err => { console.error(err) })
    },
    // 生成勾选完的路由结构
    generateTree(routes, basePath = '/', checkedKeys) {
      const res = []

      for (const route of routes) { // 生成每个路由的绝对路径
        const routePath = path.resolve(basePath, route.path)

        // recursive child routes
        if (route.children) { // 递归children
          route.children = this.generateTree(route.children, routePath, checkedKeys)
        }
        // 如果勾选结果的路径包含有遍历全部路由的当前路由，或该路由没有子路由，把该路由放置
        if (checkedKeys.includes(routePath) || (route.children && route.children.length >= 1)) {
          res.push(route)
        }
      }
      return res
    },
    async confirmRole() {
      const isEdit = this.dialogType === 'edit'
      const checkedKeys = this.$refs.tree.getCheckedKeys() // 选中的所有节点的keys生成数组
      console.log('checkedKeys', checkedKeys)
      // 深度克隆全部路由列表，将勾选完的路由和全部路由对比，生成勾选完的完整路由结构
      this.role.routes = this.generateTree(deepClone(this.serviceRoutes), '/', checkedKeys)
      // 如果是修改角色权限菜单
      if (isEdit) {
        await updateRole(this.role.key, this.role) // 调接口更新该角色菜单权限
        for (let index = 0; index < this.rolesList.length; index++) {
          if (this.rolesList[index].key === this.role.key) {
            this.rolesList.splice(index, 1, Object.assign({}, this.role))
            break
          }
        }
      } else { // 如果不是编辑状态，就是新增角色信息，调接口新增角色
        const { data } = await addRole(this.role)
        this.role.key = data.key
        this.rolesList.push(this.role)
      }

      const { description, key, name } = this.role
      this.dialogVisible = false
      this.$notify({ // 提示信息
        title: 'Success',
        dangerouslyUseHTMLString: true,
        message: `
            <div>Role Key: ${key}</div>
            <div>Role Name: ${name}</div>
            <div>Description: ${description}</div>
          `,
        type: 'success'
      })
    },
    // reference: src/view/layout/components/Sidebar/SidebarItem.vue
    onlyOneShowingChild(children = [], parent) { // 参数是子路由。父路由
      let onlyOneChild = null
      const showingChildren = children.filter(item => !item.hidden) // 拿到子路由中children中不是hidden的路由展示
      // 当只有一条子路由时，该子路由就是自己
      // When there is only one child route, the child route is displayed by default
      if (showingChildren.length === 1) {
        // path.resolve()方法可以将多个路径解析为一个规范化的绝对路径，parent.path为根路径，onlyOneChild.path为拼接路径
        onlyOneChild = showingChildren[0]
        onlyOneChild.path = path.resolve(parent.path, onlyOneChild.path)
        // 返回子路由的完整路由信息
        return onlyOneChild
      }
      // 如果没有要显示的子路由，则显示父路由
      // Show parent if there are no child route to display
      if (showingChildren.length === 0) {
        onlyOneChild = { ... parent, path: '', noShowingChildren: true }
        return onlyOneChild
      }

      return false
    }
  }
}