[JavaScript知识库]路由权限列表转trees

//后端返回的路由数据（不是树）
![在这里插入图片描述](https://img-blog.csdnimg.cn/3c43830ca98b494bb4f20945469c3a7f.png?x-oss-process=image/watermark,type_d3F5LXplbmhlaQ,shadow_50,text_Q1NETiBALS3ljJfmtbfpgZPnmoTlpI_lpKnkuI3kvJror7Tlho3op4EtLQ==,size_19,color_FFFFFF,t_70,g_se,x_16)

**// libs->utils  工具函数，将上图数据结构转换为trees**
function formatRouterTree(data) {
  let parents = data.filter(p => p.pid === 0),
      children = data.filter(c => c.pid !== 0);
  // 递归
  dataToTree(parents,children);

  function dataToTree(parents,children) {
    parents.map((p) => {
      children.map((c, i) => {
        if(c.pid === p.id) {
          let _c = JSON.parse(JSON.stringify(children));
          _c.splice(i, 1);
          dataToTree([c],_c); 

          if(p.children) {
            p.children.push(c);
          } else {
            p.children = [c];
          }
        }
      })
    })
  }

  return parents;
}
// 生成项目中需要的路由格式,要在main.js中调用
// 处理路由函数(递归)
function generateRouter(userRouters) {
  let newRouters = userRouters.map((r) => {
    let routes = {
      path: r.path,
      name: r.name,
      component: () => import(`@/views/${r.name}`)
    }
    if(r.children) {
      routes.children = generateRouter(r.children)
    }
    return routes;
  })
  return newRouters;
}

export {
  formatRouterTree,
  generateRouter
}

**// store->state.js** 
export default {
  uid: 2,
  hasAuth: false,
  userRouters: []
}

**// store->actions.js  请求数据api，将数据放入store中**
import { getUserRouters } from "../services";
import { formatRouterTree } from "./index.js";

export default {
  async setUserRouters ({ commit, state }) {
    const userRouters = await getUserRouters(state.uid),
          payload = formatRouterTree(userRouters);
    
    commit('setUserRouters', payload);
    commit('setAuth', true)
  }
}

**// store->mutations.js**  
export default {
  setAuth(state, auth) {
    state.hasAuth = auth
  },

  setUserRouters(state, userRouters) {
    state.userRouters = userRouters
  }
}

**// main.js**
import { generateRouter, formatRouterTree } from "@/libs/utils";

formatRouterTree.beforeEach((async(to, from, next) => {
  if(!store.state.hasAuth) {
    await store.dispatch('setUserRouters');
    const newRoutes = generateRouter(store.state.userRouters);
    router.addRoutes(newRoutes);
    next({ path: to.path })
  } else {
    next();
  }
}))

// 完成上述步骤，就已经将后台返回的路由处理结束，接下来就根据后台返回的路由建立对应的组件就可以了