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。
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 {}`
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
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。
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!
