146

I want to manually compile some HTML containing directives. What is the equivalent of $compile in Angular 2?

For example, in Angular 1, I could dynamically compile a fragment of HTML and append it to the DOM:

var e = angular.element('<div directive></div>');
element.append(e);
$compile(e)($scope);
4
  • 9
    Most these answers (except 1 now deprecated answer) are NOT the equivalent of angular 1 $compile. $compile takes an HTML string and compiles components and expressions contained there. These answers simply creates pre-defined components (that are not yet instantiated) dynamically and CANNOT take a string argument. This is NOT the same thing. Does anyone know of the real answer to this question? Commented Apr 13, 2017 at 9:09
  • 1
    npmjs.com/package/p3x-angular-compile Commented Apr 21, 2017 at 23:02
  • Angular 4 came up with ComponentFactoryResolver which equivalent to $ compile in Angular 1.0 .See my answer stackoverflow.com/questions/34784778/… Commented Jun 23, 2017 at 4:35
  • 1
    @danday74 - I agree that none of these answers provide the ability to compile arbitrary HTML templates, instead they just select from a set of pre-existing components. I found the real answer here, which works in Angular 8 at least: stackoverflow.com/questions/61137899/…. See the one answer, which provides a working StackBlitz which compiles an arbitrary run-time-generated HTML template. Commented Jul 20, 2020 at 16:46

9 Answers 9

135

Angular 2.3.0 (2016-12-07)

To get all the details check:

To see that in action:

The principals:

1) Create Template
2) Create Component
3) Create Module
4) Compile Module
5) Create (and cache) ComponentFactory
6) use Target to create an Instance of it

A quick overview how to create a Component

createNewComponent (tmpl:string) {
  @Component({
      selector: 'dynamic-component',
      template: tmpl,
  })
  class CustomDynamicComponent  implements IHaveDynamicData {
      @Input()  public entity: any;
  };
  // a component for this particular template
  return CustomDynamicComponent;
}

A way how to inject component into NgModule

createComponentModule (componentType: any) {
  @NgModule({
    imports: [
      PartsModule, // there are 'text-editor', 'string-editor'...
    ],
    declarations: [
      componentType
    ],
  })
  class RuntimeComponentModule
  {
  }
  // a module for just this Type
  return RuntimeComponentModule;
}

A code snippet how to create a ComponentFactory (and cache it)

public createComponentFactory(template: string)
    : Promise<ComponentFactory<IHaveDynamicData>> {    
    let factory = this._cacheOfFactories[template];

    if (factory) {
        console.log("Module and Type are returned from cache")

        return new Promise((resolve) => {
            resolve(factory);
        });
    }

    // unknown template ... let's create a Type for it
    let type   = this.createNewComponent(template);
    let module = this.createComponentModule(type);

    return new Promise((resolve) => {
        this.compiler
            .compileModuleAndAllComponentsAsync(module)
            .then((moduleWithFactories) =>
            {
                factory = _.find(moduleWithFactories.componentFactories
                                , { componentType: type });

                this._cacheOfFactories[template] = factory;

                resolve(factory);
            });
    });
}

A code snippet how to use the above result

  // here we get Factory (just compiled or from cache)
  this.typeBuilder
      .createComponentFactory(template)
      .then((factory: ComponentFactory<IHaveDynamicData>) =>
    {
        // Target will instantiate and inject component (we'll keep reference to it)
        this.componentRef = this
            .dynamicComponentTarget
            .createComponent(factory);

        // let's inject @Inputs to component instance
        let component = this.componentRef.instance;

        component.entity = this.entity;
        //...
    });

The full description with all the details read here, or observe working example

.

.

OBSOLETE - Angular 2.0 RC5 related (RC5 only)

to see previous solutions for previous RC versions, please, search through the history of this post

Sign up to request clarification or add additional context in comments.

25 Comments

Thanks a lot, I was looking for a working example of ComponentFactory and ViewContainerRef to replace the now deprecated DynamicComponentLoader.
@maxou That is lo-dash reference in the index.html just add that reference and all will work
Is this really this difficult? I used to be able to just do something like this: $compile($element.contents())($scope.$new()); and now it's hundreds of lines of code, complete with NgModule creation... This is the kind of thing that makes me want to steer clear of NG2 and move on to something better.
What is advantage of using JitCompiler if your example might work with Compiler from @angular/core? plnkr.co/edit/UxgkiT?p=preview
Oh my god, how many lines of code I should write just to compile a small element. I didn't understand well
|
35

Note: As @BennyBottema mentions in a comment, DynamicComponentLoader is now deprecated, hence so is this answer.


Angular2 doesn't have any $compile equivalent. You can use DynamicComoponentLoader and hack with ES6 classes to compile your code dynamically (see this plunk):

import {Component, DynamicComponentLoader, ElementRef, OnInit} from 'angular2/core'

function compileToComponent(template, directives) {
  @Component({ 
    selector: 'fake', 
    template , directives
  })
  class FakeComponent {};
  return FakeComponent;
}

@Component({
  selector: 'hello',
  template: '<h1>Hello, Angular!</h1>'
})
class Hello {}

@Component({
  selector: 'my-app',
  template: '<div #container></div>',
})
export class App implements OnInit {
  constructor(
    private loader: DynamicComponentLoader, 
    private elementRef: ElementRef,
  ) {}

  ngOnInit() {} {
    const someDynamicHtml = `<hello></hello><h2>${Date.now()}</h2>`;

    this.loader.loadIntoLocation(
      compileToComponent(someDynamicHtml, [Hello])
      this.elementRef,
      'container'
    );
  }
}

But it will work only until html parser is inside angular2 core.

8 Comments

Awesome trick! but in case my dynamic component has some inputs is it possible to bind dynamic data as well ?
answering to my own question: it is possible through passing data to the compiling function. here the plunk plnkr.co/edit/dK6l7jiWt535jOw1Htct?p=preview
This solution is only working with beta-0. From beta 1 to 15 the example code returns an error. Error: There is no component directive at element [object Object]
Since rc1 DynamicComponentLoader has become deprecated
@BennyBottema since DynamicComponentLoader is deprecated, how do we do the same sort of thing in Angular 2? Say I have a modal dialog and I want to dynamically load a new component as it's contents
|
18

Angular Version I have Used - Angular 4.2.0

Angular 4 is came up with ComponentFactoryResolver to load components at runtime. This is a kind of same implementation of $compile in Angular 1.0 which serves your need

In this below example I am loading ImageWidget component dynamically in to a DashboardTileComponent

In order to load a component you need a directive that you can apply to ng-template which will helps to place the dynamic component

WidgetHostDirective

 import { Directive, ViewContainerRef } from '@angular/core';

    @Directive({
      selector: '[widget-host]',
    })
    export class DashboardTileWidgetHostDirective {
      constructor(public viewContainerRef: ViewContainerRef) { 


      }
    }

this directive injects ViewContainerRef to gain access to the view container of the element that will host the dynamically added component.

DashboardTileComponent(Place holder component to render the dynamic component)

This component accepts an input which is coming from a parent components or you can load from your service based on your implementation. This component is doing the major role to resolve the components at runtime. In this method you can also see a method named renderComponent() which ultimately loads the component name from a service and resolve with ComponentFactoryResolver and finally setting data to the dynamic component.

import { Component, Input, OnInit, AfterViewInit, ViewChild, ComponentFactoryResolver, OnDestroy } from '@angular/core';
import { DashboardTileWidgetHostDirective } from './DashbardWidgetHost.Directive';
import { TileModel } from './Tile.Model';
import { WidgetComponentService } from "./WidgetComponent.Service";


@Component({
    selector: 'dashboard-tile',
    templateUrl: 'app/tile/DashboardTile.Template.html'
})

export class DashboardTileComponent implements OnInit {
    @Input() tile: any;
    @ViewChild(DashboardTileWidgetHostDirective) widgetHost: DashboardTileWidgetHostDirective;
    constructor(private _componentFactoryResolver: ComponentFactoryResolver,private widgetComponentService:WidgetComponentService) {

    }

    ngOnInit() {

    }
    ngAfterViewInit() {
        this.renderComponents();
    }
    renderComponents() {
        let component=this.widgetComponentService.getComponent(this.tile.componentName);
        let componentFactory = this._componentFactoryResolver.resolveComponentFactory(component);
        let viewContainerRef = this.widgetHost.viewContainerRef;
        let componentRef = viewContainerRef.createComponent(componentFactory);
        (<TileModel>componentRef.instance).data = this.tile;

    }
}

DashboardTileComponent.html

 <div class="col-md-2 col-lg-2 col-sm-2 col-default-margin col-default">        
                        <ng-template widget-host></ng-template>

          </div>

WidgetComponentService

This is a service factory to register all the components that you want to resolve dynamically

import { Injectable }           from '@angular/core';
import { ImageTextWidgetComponent } from "../templates/ImageTextWidget.Component";
@Injectable()
export class WidgetComponentService {
  getComponent(componentName:string) {
          if(componentName==="ImageTextWidgetComponent"){
              return ImageTextWidgetComponent
          }
  }
}

ImageTextWidgetComponent(component we are loading at runtime)

import { Component, OnInit, Input } from '@angular/core';


@Component({
    selector: 'dashboard-imagetextwidget',
    templateUrl: 'app/templates/ImageTextWidget.html'
})

export class ImageTextWidgetComponent implements OnInit {
     @Input() data: any;
    constructor() { }

    ngOnInit() { }
}

Add Finally add this ImageTextWidgetComponent in to your app module as entryComponent

@NgModule({
    imports: [BrowserModule],
    providers: [WidgetComponentService],
    declarations: [
        MainApplicationComponent,
        DashboardHostComponent,
        DashboardGroupComponent,
        DashboardTileComponent,
        DashboardTileWidgetHostDirective,
        ImageTextWidgetComponent
        ],
    exports: [],
    entryComponents: [ImageTextWidgetComponent],
    bootstrap: [MainApplicationComponent]
})
export class DashboardModule {
    constructor() {

    }
}

TileModel

 export interface TileModel {
      data: any;
    }

Orginal Reference from my blog

Official Documentation

Download Sample Source Code

11 Comments

You forgot to mention about entryComponents. Without it your solution won't work
ComponentFactoryResolver was in angular2. And i think it is not equivalent of $compile
@yurzui . But it serves the need of $compile right??
@yurzui I was used the same kind of implementation using $compile. When we remove entry components from the module it will throw an error ImageTextWidgetComponent is not loaded. But application still works
@BecarioSenior if you are not cast to any model class , it will be default dynamic. In this example the type of property data is any , which means you can pass any data to the dynamic component as input. It's give more readability to your code.
|
9

this npm package made it easier for me: https://www.npmjs.com/package/ngx-dynamic-template

usage:

<ng-template dynamic-template
             [template]="'some value:{{param1}}, and some component <lazy-component></lazy-component>'"
             [context]="{param1:'value1'}"
             [extraModules]="[someDynamicModule]"></ng-template>

Comments

3

In order to dinamically create an instance of a component and attach it to your DOM you can use the following script and should work in Angular RC:

html template:

<div>
  <div id="container"></div>
  <button (click)="viewMeteo()">Meteo</button>
  <button (click)="viewStats()">Stats</button>
</div>

Loader component

import { Component, DynamicComponentLoader, ElementRef, Injector } from '@angular/core';
import { WidgetMeteoComponent } from './widget-meteo';
import { WidgetStatComponent } from './widget-stat';

@Component({
  moduleId: module.id,
  selector: 'widget-loader',
  templateUrl: 'widget-loader.html',
})
export class WidgetLoaderComponent  {

  constructor( elementRef: ElementRef,
               public dcl:DynamicComponentLoader,
               public injector: Injector) { }

  viewMeteo() {
    this.dcl.loadAsRoot(WidgetMeteoComponent, '#container', this.injector);
  }

  viewStats() {
    this.dcl.loadAsRoot(WidgetStatComponent, '#container', this.injector);
  }

}

1 Comment

The DynamicComponentLoader is no more :'( After that was deprecated, there was ComponentResolver. And now there is the ComponentFactoryResolver (blog.rangle.io/dynamically-creating-components-with-angular-2)
3

Angular TypeScript/ES6 (Angular 2+)

Works with AOT + JIT at once together.

I created how to use it here: https://github.com/patrikx3/angular-compile

npm install p3x-angular-compile

Component: Should have a context and some html data...

Html:

<div [p3x-compile]="data" [p3x-compile-context]="ctx">loading ...</div>

1 Comment

It' s not obvious what 'Angular TypeScript' title means. Is the solution useless for ES5 and ES6? It would be helpful to provide the example of programmatic use of this package, a direct counterpart to $compile(...)($scope). There's nothing on it even in repo readme.
2

You can see the component, that allow to compile simple dynamic Angular components https://www.npmjs.com/package/@codehint-ng/html-compiler

1 Comment

it worked using this library! :) thanks for the recommendation.
0

I know this issue is old, but I spent weeks trying to figure out how to make this work with AOT enabled. I was able to compile an object but never able to execute existing components. Well I finally decided to change tact, as I was't looking to compile code so much as execute a custom template. My thought was to add the html which anyone can do and loop though the existing factories. In doing so I can search for the element/attribute/etc. names and execute the component on that HTMLElement. I was able to get it working and figured I should share this to save someone else the immense amount of time I wasted on it.

@Component({
    selector: "compile",
    template: "",
    inputs: ["html"]
})
export class CompileHtmlComponent implements OnDestroy {
    constructor(
        private content: ViewContainerRef,
        private injector: Injector,
        private ngModRef: NgModuleRef<any>
    ) { }

    ngOnDestroy() {
        this.DestroyComponents();
    }

    private _ComponentRefCollection: any[] = null;
    private _Html: string;

    get Html(): string {
        return this._Html;
    }
    @Input("html") set Html(val: string) {
        // recompile when the html value is set
        this._Html = (val || "") + "";
        this.TemplateHTMLCompile(this._Html);
    }

    private DestroyComponents() { // we need to remove the components we compiled
        if (this._ComponentRefCollection) {
            this._ComponentRefCollection.forEach((c) => {
                c.destroy();
            });
        }
        this._ComponentRefCollection = new Array();
    }

    private TemplateHTMLCompile(html) {
        this.DestroyComponents();
        this.content.element.nativeElement.innerHTML = html;
        var ref = this.content.element.nativeElement;
        var factories = (this.ngModRef.componentFactoryResolver as any)._factories;
        // here we loop though the factories, find the element based on the selector
        factories.forEach((comp: ComponentFactory<unknown>) => {
            var list = ref.querySelectorAll(comp.selector);
            list.forEach((item) => {
                var parent = item.parentNode;
                var next = item.nextSibling;
                var ngContentNodes: any[][] = new Array(); // this is for the viewchild/viewchildren of this object

                comp.ngContentSelectors.forEach((sel) => {
                    var ngContentList: any[] = new Array();

                    if (sel == "*") // all children;
                    {
                        item.childNodes.forEach((c) => {
                            ngContentList.push(c);
                        });
                    }
                    else {
                        var selList = item.querySelectorAll(sel);

                        selList.forEach((l) => {
                            ngContentList.push(l);
                        });
                    }

                    ngContentNodes.push(ngContentList);
                });
                // here is where we compile the factory based on the node we have
                let component = comp.create(this.injector, ngContentNodes, item, this.ngModRef);

                this._ComponentRefCollection.push(component); // save for our destroy call
                // we need to move the newly compiled element, as it was appended to this components html
                if (next) parent.insertBefore(component.location.nativeElement, next);
                else parent.appendChild(component.location.nativeElement);

                component.hostView.detectChanges(); // tell the component to detectchanges
            });
        });
    }
}

Comments

-8

If you want to inject html code use directive

<div [innerHtml]="htmlVar"></div>

If you want to load whole component in some place, use DynamicComponentLoader:

https://angular.io/docs/ts/latest/api/core/DynamicComponentLoader-class.html

2 Comments

I want to inject a fragment of HTML as a string and pass it to a component compiler, and then append that component in my DOM. Can you give an example of how either of your solutions can work?
using innerHtml doesn't compile any components inside htmlVar

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