我想动态创建一个模板。这应该用于在运行时构建ComponentType,并将其放置(甚至替换)到宿主组件内部的某个位置。

直到RC4我使用ComponentResolver,但与RC5我得到以下消息:

ComponentResolver is deprecated for dynamic compilation.
Use ComponentFactoryResolver together with @NgModule/@Component.entryComponents or ANALYZE_FOR_ENTRY_COMPONENTS provider instead.
For runtime compile only, you can also use Compiler.compileComponentSync/Async.

我找到了这个文档(Angular 2同步动态组件创建)

你要明白我可以用任何一种

一种带有ComponentFactoryResolver的动态ngIf。如果我在@Component({entryComponents: [comp1, comp2],…})内部传递已知的组件-我可以使用.resolveComponentFactory(componentToRender); 真正的运行时编译,使用编译器…

但问题是如何使用编译器?上面的说明说,我应该调用:Compiler.compileComponentSync/Async -那么如何?

为例。我想为一种设置创建(基于一些配置条件)这种模板

<form>
   <string-editor
     [propertyName]="'code'"
     [entity]="entity"
   ></string-editor>
   <string-editor
     [propertyName]="'description'"
     [entity]="entity"
   ></string-editor>
   ...

在另一种情况下,这个(字符串编辑器被文本编辑器取代)

<form>
   <text-editor
     [propertyName]="'code'"
     [entity]="entity"
   ></text-editor>
   ...

等等(根据属性类型设置不同的数字/日期/引用编辑器,为某些用户跳过一些属性……)例如,这是一个例子,实际的配置可以生成更多不同和复杂的模板。

模板正在改变,所以我不能使用ComponentFactoryResolver和传递现有的…我需要一个解决方案与编译器。


当前回答

在Ophir Stern的答案基础上,这里有一个与Angular 4中的AoT一起工作的变体。唯一的问题是我不能向DynamicComponent注入任何服务,但我可以接受。

注意:我还没有测试Angular 5。

import { Component, OnInit, Input, NgModule, NgModuleFactory, Compiler, EventEmitter, Output } from '@angular/core';
import { JitCompilerFactory } from '@angular/compiler';

export function createJitCompiler() {
  return new JitCompilerFactory([{
    useDebug: false,
    useJit: true
  }]).createCompiler();
}

type Bindings = {
  [key: string]: any;
};

@Component({
  selector: 'app-compile',
  template: `
    <div *ngIf="dynamicComponent && dynamicModule">
      <ng-container *ngComponentOutlet="dynamicComponent; ngModuleFactory: dynamicModule;">
      </ng-container>
    </div>
  `,
  styleUrls: ['./compile.component.scss'],
  providers: [{provide: Compiler, useFactory: createJitCompiler}]
})
export class CompileComponent implements OnInit {

  public dynamicComponent: any;
  public dynamicModule: NgModuleFactory<any>;

  @Input()
  public bindings: Bindings = {};
  @Input()
  public template: string = '';

  constructor(private compiler: Compiler) { }

  public ngOnInit() {

    try {
      this.loadDynamicContent();
    } catch (err) {
      console.log('Error during template parsing: ', err);
    }

  }

  private loadDynamicContent(): void {

    this.dynamicComponent = this.createNewComponent(this.template, this.bindings);
    this.dynamicModule = this.compiler.compileModuleSync(this.createComponentModule(this.dynamicComponent));

  }

  private createComponentModule(componentType: any): any {

    const runtimeComponentModule = NgModule({
      imports: [],
      declarations: [
        componentType
      ],
      entryComponents: [componentType]
    })(class RuntimeComponentModule { });

    return runtimeComponentModule;

  }

  private createNewComponent(template: string, bindings: Bindings): any {

    const dynamicComponent = Component({
      selector: 'app-dynamic-component',
      template: template
    })(class DynamicComponent implements OnInit {

      public bindings: Bindings;

      constructor() { }

      public ngOnInit() {
        this.bindings = bindings;
      }

    });

    return dynamicComponent;

  }

}

希望这能有所帮助。

干杯!

其他回答

EDIT (26/08/2017): The solution below works well with Angular2 and 4. I've updated it to contain a template variable and click handler and tested it with Angular 4.3. For Angular4, ngComponentOutlet as described in Ophir's answer is a much better solution. But right now it does not support inputs & outputs yet. If [this PR](https://github.com/angular/angular/pull/15362] is accepted, it would be possible through the component instance returned by the create event. ng-dynamic-component may be the best and simplest solution altogether, but I haven't tested that yet.

@Long Field的答案是正确的!下面是另一个(同步)例子:

import {Compiler, Component, NgModule, OnInit, ViewChild,
  ViewContainerRef} from '@angular/core'
import {BrowserModule} from '@angular/platform-browser'

@Component({
  selector: 'my-app',
  template: `<h1>Dynamic template:</h1>
             <div #container></div>`
})
export class App implements OnInit {
  @ViewChild('container', { read: ViewContainerRef }) container: ViewContainerRef;

  constructor(private compiler: Compiler) {}

  ngOnInit() {
    this.addComponent(
      `<h4 (click)="increaseCounter()">
        Click to increase: {{counter}}
      `enter code here` </h4>`,
      {
        counter: 1,
        increaseCounter: function () {
          this.counter++;
        }
      }
    );
  }

  private addComponent(template: string, properties?: any = {}) {
    @Component({template})
    class TemplateComponent {}

    @NgModule({declarations: [TemplateComponent]})
    class TemplateModule {}

    const mod = this.compiler.compileModuleAndAllComponentsSync(TemplateModule);
    const factory = mod.componentFactories.find((comp) =>
      comp.componentType === TemplateComponent
    );
    const component = this.container.createComponent(factory);
    Object.assign(component.instance, properties);
    // If properties are changed at a later stage, the change detection
    // may need to be triggered manually:
    // component.changeDetectorRef.detectChanges();
  }
}

@NgModule({
  imports: [ BrowserModule ],
  declarations: [ App ],
  bootstrap: [ App ]
})
export class AppModule {}

请访问http://plnkr.co/edit/fdP9Oc。

我自己也在尝试如何将RC4更新到RC5,因此我偶然发现了这个条目和动态组件创建的新方法,对我来说仍然有点神秘,所以我不会建议任何关于组件工厂解析器的建议。

但是,我能建议的是在这种情况下创建组件的更清晰的方法-只需在模板中使用switch,根据某些条件创建字符串编辑器或文本编辑器,就像这样:

<form [ngSwitch]="useTextarea">
    <string-editor *ngSwitchCase="false" propertyName="'code'" 
                 [entity]="entity"></string-editor>
    <text-editor *ngSwitchCase="true" propertyName="'code'" 
                 [entity]="entity"></text-editor>
</form>

顺便说一下,[prop]表达式中的“[”有一个含义,这表明了一种数据绑定方式,因此,如果你知道你不需要将属性绑定到变量,你可以甚至应该省略这些。

我决定把我学到的东西都压缩到一个文件里。 与RC5之前相比,这里有很多东西值得考虑。注意,这个源文件包括AppModule和AppComponent。

import {
  Component, Input, ReflectiveInjector, ViewContainerRef, Compiler, NgModule, ModuleWithComponentFactories,
  OnInit, ViewChild
} from '@angular/core';
import {BrowserModule} from '@angular/platform-browser';

@Component({
  selector: 'app-dynamic',
  template: '<h4>Dynamic Components</h4><br>'
})
export class DynamicComponentRenderer implements OnInit {

  factory: ModuleWithComponentFactories<DynamicModule>;

  constructor(private vcRef: ViewContainerRef, private compiler: Compiler) { }

  ngOnInit() {
    if (!this.factory) {
      const dynamicComponents = {
        sayName1: {comp: SayNameComponent, inputs: {name: 'Andrew Wiles'}},
        sayAge1: {comp: SayAgeComponent, inputs: {age: 30}},
        sayName2: {comp: SayNameComponent, inputs: {name: 'Richard Taylor'}},
        sayAge2: {comp: SayAgeComponent, inputs: {age: 25}}};
      this.compiler.compileModuleAndAllComponentsAsync(DynamicModule)
        .then((moduleWithComponentFactories: ModuleWithComponentFactories<DynamicModule>) => {
          this.factory = moduleWithComponentFactories;
          Object.keys(dynamicComponents).forEach(k => {
            this.add(dynamicComponents[k]);
          })
        });
    }
  }

  addNewName(value: string) {
    this.add({comp: SayNameComponent, inputs: {name: value}})
  }

  addNewAge(value: number) {
    this.add({comp: SayAgeComponent, inputs: {age: value}})
  }

  add(comp: any) {
    const compFactory = this.factory.componentFactories.find(x => x.componentType === comp.comp);
    // If we don't want to hold a reference to the component type, we can also say: const compFactory = this.factory.componentFactories.find(x => x.selector === 'my-component-selector');
    const injector = ReflectiveInjector.fromResolvedProviders([], this.vcRef.parentInjector);
    const cmpRef = this.vcRef.createComponent(compFactory, this.vcRef.length, injector, []);
    Object.keys(comp.inputs).forEach(i => cmpRef.instance[i] = comp.inputs[i]);
  }
}

@Component({
  selector: 'app-age',
  template: '<div>My age is {{age}}!</div>'
})
class SayAgeComponent {
  @Input() public age: number;
};

@Component({
  selector: 'app-name',
  template: '<div>My name is {{name}}!</div>'
})
class SayNameComponent {
  @Input() public name: string;
};

@NgModule({
  imports: [BrowserModule],
  declarations: [SayAgeComponent, SayNameComponent]
})
class DynamicModule {}

@Component({
  selector: 'app-root',
  template: `
        <h3>{{message}}</h3>
        <app-dynamic #ad></app-dynamic>
        <br>
        <input #name type="text" placeholder="name">
        <button (click)="ad.addNewName(name.value)">Add Name</button>
        <br>
        <input #age type="number" placeholder="age">
        <button (click)="ad.addNewAge(age.value)">Add Age</button>
    `,
})
export class AppComponent {
  message = 'this is app component';
  @ViewChild(DynamicComponentRenderer) dcr;

}

@NgModule({
  imports: [BrowserModule],
  declarations: [AppComponent, DynamicComponentRenderer],
  bootstrap: [AppComponent]
})
export class AppModule {}`

在角7。我使用了角元素。

安装@angular-elements NPM I @angular/elements 创建配件服务。

import { Injectable, Injector } from '@angular/core';
import { createCustomElement } from '@angular/elements';
import { IStringAnyMap } from 'src/app/core/models';
import { AppUserIconComponent } from 'src/app/shared';

const COMPONENTS = {
  'user-icon': AppUserIconComponent
};

@Injectable({
  providedIn: 'root'
})
export class DynamicComponentsService {
  constructor(private injector: Injector) {

  }

  public register(): void {
    Object.entries(COMPONENTS).forEach(([key, component]: [string, any]) => {
      const CustomElement = createCustomElement(component, { injector: this.injector });
      customElements.define(key, CustomElement);
    });
  }

  public create(tagName: string, data: IStringAnyMap = {}): HTMLElement {
    const customEl = document.createElement(tagName);

    Object.entries(data).forEach(([key, value]: [string, any]) => {
      customEl[key] = value;
    });

    return customEl;
  }
}

注意,你的自定义元素标签必须与angular组件选择器不同。 在AppUserIconComponent:

...
selector: app-user-icon
...

在这种情况下,自定义标签名称我使用“user-icon”。

然后你必须在AppComponent中调用register:

@Component({
  selector: 'app-root',
  template: '<router-outlet></router-outlet>'
})
export class AppComponent {
  constructor(   
    dynamicComponents: DynamicComponentsService,
  ) {
    dynamicComponents.register();
  }

}

现在在你代码的任何地方你都可以这样使用它:

dynamicComponents.create('user-icon', {user:{...}});

或者像这样:

const html = `<div class="wrapper"><user-icon class="user-icon" user='${JSON.stringify(rec.user)}'></user-icon></div>`;

this.content = this.domSanitizer.bypassSecurityTrustHtml(html);

(模板):

<div class="comment-item d-flex" [innerHTML]="content"></div>

注意,在第二种情况下,必须传递带有JSON的对象。Stringify,然后再次解析它。我找不到更好的解决办法了。

2019年6月答案

好消息!看起来@angular/cdk包现在对门户提供了一流的支持!

在撰写本文时,我并没有发现上面的官方文档有什么特别的帮助(特别是在向动态组件发送数据和从动态组件接收事件方面)。总之,你需要:

步骤1)更新AppModule

从@angular/cdk/portal包中导入PortalModule,在entryComponents中注册你的动态组件

@NgModule({
  declarations: [ ..., AppComponent, MyDynamicComponent, ... ]
  imports:      [ ..., PortalModule, ... ],
  entryComponents: [ ..., MyDynamicComponent, ... ]
})
export class AppModule { }

步骤2。选项A:如果你不需要向动态组件传递数据和从动态组件接收事件:

@Component({
  selector: 'my-app',
  template: `
    <button (click)="onClickAddChild()">Click to add child component</button>
    <ng-template [cdkPortalOutlet]="myPortal"></ng-template>
  `
})
export class AppComponent  {
  myPortal: ComponentPortal<any>;
  onClickAddChild() {
    this.myPortal = new ComponentPortal(MyDynamicComponent);
  }
}

@Component({
  selector: 'app-child',
  template: `<p>I am a child.</p>`
})
export class MyDynamicComponent{
}

看看它的实际应用

步骤2。选项B:如果你确实需要向动态组件传递数据并从动态组件接收事件:

// A bit of boilerplate here. Recommend putting this function in a utils 
// file in order to keep your component code a little cleaner.
function createDomPortalHost(elRef: ElementRef, injector: Injector) {
  return new DomPortalHost(
    elRef.nativeElement,
    injector.get(ComponentFactoryResolver),
    injector.get(ApplicationRef),
    injector
  );
}

@Component({
  selector: 'my-app',
  template: `
    <button (click)="onClickAddChild()">Click to add random child component</button>
    <div #portalHost></div>
  `
})
export class AppComponent {

  portalHost: DomPortalHost;
  @ViewChild('portalHost') elRef: ElementRef;

  constructor(readonly injector: Injector) {
  }

  ngOnInit() {
    this.portalHost = createDomPortalHost(this.elRef, this.injector);
  }

  onClickAddChild() {
    const myPortal = new ComponentPortal(MyDynamicComponent);
    const componentRef = this.portalHost.attach(myPortal);
    setTimeout(() => componentRef.instance.myInput 
      = '> This is data passed from AppComponent <', 1000);
    // ... if we had an output called 'myOutput' in a child component, 
    // this is how we would receive events...
    // this.componentRef.instance.myOutput.subscribe(() => ...);
  }
}

@Component({
  selector: 'app-child',
  template: `<p>I am a child. <strong>{{myInput}}</strong></p>`
})
export class MyDynamicComponent {
  @Input() myInput = '';
}

看看它的实际应用