Angular 6：将急切加载转换为延迟加载

Question

我有一个使用急切加载的完整 Angular 应用程序。 我想将其转换为延迟加载，但是因为我对所有路线都有保护，并且所有路线都是通往受保护的主要路线的子路线，所以我不知道是否可以这样做并且仍然使它起作用就像急切加载一样。

这是我在 app-routing.module 中的路由数组：

// Routing array - set routes to each html page
const appRoutes: Routes = [
  { path: 'login/:id', canActivate: [AuthGuard], children: [] },
  { path: '', canActivateChild: [AuthGuard], children: [
    { path: '', redirectTo: '/courses', pathMatch: 'full' },
    { path: 'courses', component: CourseListComponent,  pathMatch: 'full'},
    { path: 'courses/:courseId', component: CourseDetailComponent, pathMatch: 'full' },
    { path: 'courses/:courseId/unit/:unitId', component: CoursePlayComponent,
      children: [
        { path: '', component: CourseListComponent },
        { path: 'lesson/:lessonId', component: CourseLessonComponent, data:{ type: 'lesson'} },
        { path: 'quiz/:quizId', component: CourseQuizComponent, data: {type: 'quiz'} }
      ]}
    ]},
  { path: 'welcome', component: LandingPageComponent, pathMatch: 'full' },
  { path: '**', component: PageNotFoundComponent, pathMatch: 'full' }];

我想知道是否可以通过延迟加载来实现这一点，如果可以的话，我想知道主要思想或为此我需要知道什么。

在我做的所有教程中，我从未遇到过这种事情。 非常感谢

Answer 1

谢谢大家的回答。我成功地将我的路由转换为延迟加载。这是代码：

app-routing.module

import { NgModule } from '@angular/core';
import { Routes, RouterModule, Router } from '@angular/router';
import { AuthGuard } from './auth.guard';

import { AppComponent } from './app.component';
import { PageNotFoundComponent } from './page-not-found/page-not-found.component';
import { LandingPageComponent } from './landing-page/landing-page.component';
import { HeaderComponent } from './header/header.component';
import { CourseModule } from './courses/course.module';


const routes:Routes = [
  { path: 'welcome', component: LandingPageComponent, pathMatch: 'full' },
  { path: 'login/:id', canActivate: [AuthGuard],  children: [] },
  { path: '', canActivateChild: [AuthGuard], children: [
    { path: '', redirectTo: 'courses', pathMatch: 'full' },
    { path: 'courses',  loadChildren: () => CourseModule }
  ]},
  { path: '**', component: PageNotFoundComponent, pathMatch: 'full' }
]

@NgModule({
  imports: [RouterModule.forRoot(routes, { onSameUrlNavigation: 'reload', initialNavigation: 'enabled',
      paramsInheritanceStrategy: 'always' })],
  providers: [AuthGuard],
  exports: [RouterModule]
})


export class AppRoutingModule {  }

course-routing.module

import { NgModule } from '@angular/core';
import { RouterModule, Routes } from "@angular/router";
import { AuthGuard } from '../auth.guard';

import { CourseListComponent } from './course-list/course-list.component';
import { CourseDetailComponent } from './course-detail/course-detail.component';
import { CoursePlayComponent } from './course-play/course-play.component';
import { CourseQuizComponent } from './course-play/course-quiz/course-quiz.component';
import { CourseLessonComponent } from './course-play/course-lesson/course-lesson.component';


const routes:Routes = [
  { path: '', component: CourseListComponent, canActivate: [AuthGuard] },
  { path: ':courseId', component: CourseDetailComponent, canActivate: [AuthGuard] },
  { path: ':courseId/unit/:unitId', component: CoursePlayComponent, canActivate: [AuthGuard], canActivateChild: [AuthGuard], children: [
    { path: 'lesson/:lessonId', component: CourseLessonComponent, data:{ type: 'lesson'} },
    { path: 'quiz/:quizId', component: CourseQuizComponent, data: {type: 'quiz'}}
  ]}
]

@NgModule({
  imports: [RouterModule.forChild(routes)],
  exports: [RouterModule]
})
export class CourseRoutingModule { }

auth.guard

import { Injectable } from '@angular/core';
import { Observable, throwError } from 'rxjs';
import { Router, CanActivate, CanActivateChild, CanLoad, ActivatedRouteSnapshot, RouterStateSnapshot, NavigationExtras, Route } from '@angular/router';
import { AuthUserService } from './users/auth-user.service';
import { LocalStorage } from '@ngx-pwa/local-storage';

@Injectable()
export class AuthGuard implements CanActivate , CanActivateChild {

    constructor(private authUserService: AuthUserService, private router: Router) {   }

    canActivate(route: ActivatedRouteSnapshot, state:
       RouterStateSnapshot): boolean |
       Observable<boolean> | Promise<boolean> {
         let id, course_id;

         // save the id from route snapshot
         if (route.params) {
           id = +route.params.id;
           course_id = +route.params.courseId;
         }

         // if you try to logging with id
         if (id) {
           this.router.navigate(["/courses"]);
           return this.authUserService.login(id);
         }

         // if you're already logged in and navigate between pages
         if (this.authUserService.isLoggedIn()){
           if (course_id){
             // check if someone try to access a locked course
             if (this.authUserService.isCourseNotPartOfTheSubscription(course_id)){
               this.router.navigate(["/welcome"]);
               return false;
             }
             else
               return true;
           }
           else
             return true;
         }

         // if you are not logged and didn't try to log - redirect to landing page
         else {
           this.router.navigate(["/welcome"]);
           return false;
         }
        }

      canActivateChild(route: ActivatedRouteSnapshot,state: RouterStateSnapshot): boolean |
      Observable<boolean> | Promise<boolean> {
         return this.canActivate(route, state);
       }

       canLoad(route: ActivatedRouteSnapshot,state: RouterStateSnapshot): boolean |
       Observable<boolean> | Promise<boolean> {
         return this.canActivate(route, state);
       }
}

Answer 2

带有一般问题标题“将急切加载转换为延迟加载”。

我通过 4 个步骤分享我将急切加载转换为延迟加载的方法。

第一步：在组件文件夹中通过命令 ng g module ModuleName 创建模块

import { NgModule } from '@angular/core';
import { CommonModule } from '@angular/common';
import { RouterModule, Routes } from '@angular/router';
import { AnalysisStatusComponent } from './analysis-status.component';
import { ShareComponentModule } from '../../share-component/share-component.module';
const routes: Routes = [
  {
    path: '',
    component: AnalysisStatusComponent
  }
];

@NgModule({
  declarations: [
    AnalysisStatusComponent
  ],
  imports: [
    RouterModule.forChild(routes),
    CommonModule,
    ShareComponentModule
  ]
})
export class AnalysisStatusModule { }

第 2 步：为模块添加路由

const routes: Routes = [
      {
        path: '',
        component: AnalysisStatusComponent
      }
    ];

第 3 步： 注释掉应用模块中的组件

@NgModule({
   declarations: [
      AppComponent,
      NavBarComponent,
      LoginComponent,
      //AnalysisStatusComponent,
      PairsPipe,
      MainComponent
   ],

第 4 步： 更新应用路由中的路由

const routes: Routes = [
  //{ path: 'dashboard/analysis-status', component: AnalysisStatusComponent },
  { path: 'dashboard/analysis-status', loadChildren: './dashboard/analysis-status/analysis-status.module#AnalysisStatusModule' },
}

Answer 3

我的一个应用中的示例代码：

const routes: Routes = [
  {
    path: 'login',
    component: SignupLoginMainContainerComponent,
    canActivate: [AuthGuard],
  },
  {
    path: 'error',
    component: ErrorComponent
  },
  {
    // lazy loading payment module
    path: 'payment',
    loadChildren: './modules/payment/payment.module#PaymentModule'
  },
  {
    // lazy loading private module
    path: '',
    loadChildren: './modules/private/private.module#PrivateModule',
    canLoad: [AuthGuard]
  },
  {path: '**', redirectTo: '/login'},
];

AuthGuard 实现：

export class AuthGuard implements CanActivate, CanLoad {

canActivate(
    next: ActivatedRouteSnapshot,
    state: RouterStateSnapshot
  ): Observable<boolean> | Promise<boolean> | boolean {
    return (some condition) ? true : false
  }

canLoad(route: Route): boolean {
   return (some condition based on route etc) ? true : false
 }

}

私有模块拥有路由文件，进一步加载更多子模块：

const routes: Routes = [
  {
    path: '',
    component: PrivateComponent,
    canActivateChild: [AuthGuard],
    children: [
      {
        path: 'childOne',
        loadChildren: '../child-one/child-one.module#ChildOneModule',
        canLoad: [AuthGuard],
      },
      {
        path: 'childTwo',
        loadChildren: '../child-two/child-two.module#ChildTwoModule',
        canLoad: [AuthGuard],
      },
      {
        path: '',
        redirectTo: '/dashboard',
        pathMatch: 'full',
      },
    ],
  },
];

可以在以下位置找到另一个示例：https://github.com/ashishgkwd/bot/tree/24-lazy-loading-modules。 AdminModule 在这个中被延迟加载。

Answer 4

        For lazy loading you should use:
   import {ComponentName} from 'component path';     
        const routes: Routes = [

      //for module 

            {
                path: 'path_Name',
                loadChildren: './modules/abc/abc.module#AbcModule'
            },

       //for component
            {
              path: 'browser',
            component: ComponentName
         },
    ];