如何在TabView(PrimeNG)中延迟加载Angular 2组件？

Question

这是我的app.component.ts:

import { Component } from '@angular/core';

@Component({
    templateUrl: 'app/app.component.html',
    selector: 'my-app'
})
export class AppComponent {

}

这是我的app.component.html:

<p-tabView>
    <p-tabPanel header="Home" leftIcon="fa-bar-chart-o">
        <home-app></home-app>
    </p-tabPanel>
    <p-tabPanel header="Hierarquia" leftIcon="fa-sitemap">
        <tree-app></tree-app>
    </p-tabPanel>
    <p-tabPanel header="Configurações" leftIcon="fa-cog">
        <config-app></config-app>
    </p-tabPanel>
</p-tabView>

加载tabView时,我的三个组件(home,tree和config)已同时加载.但是,我希望在选择其选项卡时加载一个组件.怎么做？

PS:如果有帮助,TabView有一个onChange事件.

Answer 1

您可以使用SystemJsNgModuleLoaderangular2路由中使用的

Live Plunker

首先,您可以编写将加载模块的组件:

@Component({
  selector: 'dynamic-container',
  template: `
    <template #container></template>
    <div *ngIf="!loaded" class="loader"></div>
  `,
  styles: [`
    .loader {
      position: relative;
      min-height: 100px;
    }

    .loader:after {
      content: 'Loading module. Please waiting...';
      position: absolute;
      top: 50%;
      left: 50%;
      transform: translate(-50%, -50%);
    }
  `]
})
export class DynamicContainerComponent implements OnDestroy {
  @ViewChild('container', { read: ViewContainerRef }) vcRef: ViewContainerRef;
  loaded: boolean;

  constructor(private moduleLoader: SystemJsNgModuleLoader) { }

  compRef: ComponentRef<any>;

  @Input() modulePath: string;
  @Input() moduleName: string;

  _inited: boolean
  set inited(val: boolean) {
    if(val) {
      this.loadComponent();
    }
    this._inited = val;
  };

  get inited() {
    return this._inited;
  }

  loadComponent() {
    this.moduleLoader.load(`${this.modulePath}#${this.moduleName}`)
      .then((moduleFactory: NgModuleFactory<any>) => {
        const vcRef = this.vcRef;
        const ngModuleRef = moduleFactory.create(vcRef.parentInjector);
        const comp = ngModuleRef.injector.get(LazyLoadConfig).component;
        const compFactory = ngModuleRef.componentFactoryResolver.resolveComponentFactory(comp);
        this.compRef = vcRef.createComponent(compFactory, 0, ngModuleRef.injector);

        this.loaded = true;
      });
  }

  ngOnDestroy() {
    this.compRef.destroy();
  }
}

然后在您的组件中使用它:

@Component({
  selector: 'my-app',
  template: `
    <h2 class="plunker-title">How to lazy load Angular 2 components in a TabView (PrimeNG)?</h2>
    <p-tabView (onChange)="handleChange($event)">
    <p-tabPanel header="Home" leftIcon="fa-bar-chart-o">
        <home-app></home-app>
    </p-tabPanel>
    <p-tabPanel header="Hierarquia" leftIcon="fa-sitemap">
        <dynamic-container modulePath="./src/modules/tree/tree.module" moduleName="TreeModule"></dynamic-container>
    </p-tabPanel>
    <p-tabPanel header="Configurações" leftIcon="fa-cog">
        <dynamic-container modulePath="./src/modules/config/config.module" moduleName="ConfigModule"></dynamic-container>
    </p-tabPanel>
</p-tabView>
  `
})
export class AppComponent {
  @ViewChildren(DynamicContainerComponent) dynamicContainers: QueryList<DynamicContainerComponent>;

  handleChange(e) {
    let dynamicContainer = this.dynamicContainers.toArray()[e.index - 1];
    if (!dynamicContainer || dynamicContainer.inited) return;

    // prevent fast clicking and double loading
    dynamicContainer.inited = true;
  }
}

也可以看看

• 如何手动延迟加载模块？

Answer 2

经过大量研究，我可以使用router解决问题。现在应用程序非常快。

app.component.ts:

import { Component } from '@angular/core';
import { Router } from '@angular/router';

@Component({
    templateUrl: 'app/app.component.html',
    selector: 'my-app'
})
export class AppComponent {

    constructor(
        private router: Router) {
    }

    handleChange(e) {
        let index = e.index;
        let link;
        switch (index) {
            case 0:
                link = ['/home'];
                break;
            case 1:
                link = ['/hierarquia'];
                break;
            case 2:
                link = ['/config'];
                break;
        }
        this.router.navigate(link);
    }
}

app.component.html：

<div>
    <p-tabView (onChange)="handleChange($event)">
        <p-tabPanel header="Home" leftIcon="fa-bar-chart-o"></p-tabPanel>
        <p-tabPanel header="Hierarquia" leftIcon="fa-sitemap"></p-tabPanel>
        <p-tabPanel header="Configurações" leftIcon="fa-cog"></p-tabPanel>
    </p-tabView>
</div>

<router-outlet></router-outlet>

app.route.ts:

import { NgModule } from '@angular/core';
import { Routes, RouterModule } from '@angular/router';

import { AppHome } from './app.home';
import { AppTree } from './app.tree';
import { AppConfig } from './app.config';

const routes: Routes = [
    {
        path: 'home',
        component: AppHome
    },
    {
        path: 'hierarquia',
        component: AppTree
    },
    {
        path: 'config',
        component: AppConfig
    },
    {
        path: '',
        redirectTo: '/home',
        pathMatch: 'full'
    },
];

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

export const routedComponents = [AppHome, AppTree, AppConfig];

app.module.ts:

import { NgModule } from '@angular/core';
import { FormsModule, ReactiveFormsModule } from '@angular/forms';
import { HttpModule } from '@angular/http';
import { BrowserModule } from '@angular/platform-browser';
import 'rxjs/add/operator/toPromise';

import { AppConfig } from './app.config';
import { AppHeader } from './app.header';
import { AppHome } from './app.home';
import { AppTree } from './app.tree';
import { AppComponent } from './app.component';

import { AppRoutingModule, routedComponents } from './app.route';

import { InputTextModule, DataTableModule, ButtonModule, DialogModule, TabViewModule, ChartModule, TreeModule, GrowlModule, InputSwitchModule, BlockUIModule, InputMaskModule, DropdownModule } from 'primeng/primeng';

@NgModule({
    imports: [BrowserModule, FormsModule, ReactiveFormsModule, HttpModule, AppRoutingModule, InputTextModule, DataTableModule, ButtonModule, DialogModule, TabViewModule, ChartModule, TreeModule, GrowlModule, InputSwitchModule, BlockUIModule, InputMaskModule, DropdownModule],
    declarations: [AppHeader, AppComponent, AppHome, AppTree, AppConfig, routedComponents],
    bootstrap: [AppHeader, AppComponent]
})
export class AppModule { }

感谢上帝！=]