Integrate Essential JS 2 TreeView inside the Accordion in Angular Accordion component

Accordion supports to render other Essential JS 2 Components by using content property. You can give content as an element string like below, for initializing the component.

content: '<div id="element"> </div>'

The other component can be rendered with the use of provided events, such as clicked and expanding. The following procedure is to render a TreeView within the Accordion,

Import the TreeView module from ej2-navigations, for adding TreeView. Please refer the TreeView initialization steps
You can initialize the TreeView component in expanding event, by getting the element and defining the required TreeView properties.

Source

Preview

app.component.ts

app.module.ts

datasource.ts

main.ts

index.html

index.css

import { Component, ViewChild } from '@angular/core';
import { AccordionComponent } from '@syncfusion/ej2-angular-navigations';
import { Accordion, ExpandEventArgs, TreeView } from '@syncfusion/ej2-navigations';
import { DocDB, DownloadDB, PicDB } from './datasource.ts';

@Component({
    selector: 'app-container',
    template: `
    <ejs-accordion #element (expanding)="expanded($event)">
        <e-accordionitems>
          <e-accordionitem expanded='true'>
            <ng-template #header>
              <div>Documents</div>
            </ng-template>
            <ng-template #content>
              <div id="treeDoc"></div>
            </ng-template>
          </e-accordionitem>
          <e-accordionitem>
            <ng-template #header>
              <div>Downloads</div>
            </ng-template>
            <ng-template #content>
              <div id="treeDownload"></div>
            </ng-template>
          </e-accordionitem>
          <e-accordionitem>
            <ng-template #header>
              <div>Pictures</div>
            </ng-template>
            <ng-template #content>
             <div id="treePic"></div>
            </ng-template>
          </e-accordionitem>
        </e-accordionitems>
    </ejs-accordion>
        `
})

export class AppComponent {
    @ViewChild('element') acrdnInstance: AccordionComponent;
    public expanded(e: ExpandEventArgs) {
  if (e.isExpanded && [].indexOf.call(this.acrdnInstance.items, e.item) === 0 && e.element.querySelector('#treeDoc').childElementCount === 0) {
    //Initialize TreeView component
        let treeObj: TreeView = new TreeView({
        fields: { dataSource: DocDB, id: 'nodeId', text: 'nodeText', child: 'nodeChild', iconCss: 'icon', imageUrl: 'image' },
        sortOrder: 'Ascending'
    });
    //Render initialized TreeView component
    treeObj.appendTo('#treeDoc');
  }
    if (e.isExpanded && [].indexOf.call(this.acrdnInstance.items, e.item) === 1 && e.element.querySelector('#treeDownload').childElementCount === 0) {
        let treeObj: TreeView = new TreeView({
        fields: { dataSource: DownloadDB, id: 'nodeId', text: 'nodeText', child: 'nodeChild', iconCss: 'icon', imageUrl: 'image' },
        sortOrder: 'Ascending'
    });
    treeObj.appendTo('#treeDownload');
  }
      if (e.isExpanded && [].indexOf.call(this.acrdnInstance.items, e.item) === 2 && e.element.querySelector('#treePic').childElementCount === 0) {
        let treeObj: TreeView = new TreeView({
        fields: { dataSource: PicDB, id: 'nodeId', text: 'nodeText', child: 'nodeChild', iconCss: 'icon', imageUrl: 'image' },
        sortOrder: 'Ascending'
    });
    treeObj.appendTo('#treePic');
  }

    }
    ngAfterViewInit() {
    }
}

import { NgModule } from '@angular/core';
import { BrowserModule } from '@angular/platform-browser';
import { AccordionModule } from '@syncfusion/ej2-angular-navigations';
import { AppComponent } from './app.component';

/**
 * Module
 */
@NgModule({
    imports: [
        BrowserModule, AccordionModule
    ],
    declarations: [AppComponent],
    bootstrap: [AppComponent]
})
export class AppModule { }

export let DocDB: { [key: string]: Object }[] = [
    {
            nodeId: '03', nodeText: 'Documents', icon: 'folder',
            nodeChild: [
                { nodeId: '03-01', nodeText: 'Environment Pollution.docx', icon: 'docx' },
                { nodeId: '03-02', nodeText: 'Global Water, Sanitation, & Hygiene.docx', icon: 'docx' },
                { nodeId: '03-03', nodeText: 'Global Warming.ppt', icon: 'ppt' },
                { nodeId: '03-04', nodeText: 'Social Network.pdf', icon: 'pdf' },
                { nodeId: '03-05', nodeText: 'Youth Empowerment.pdf', icon: 'pdf' },
            ]
        },
    ]
    
  export let DownloadDB: { [key: string]: Object }[] = [
        {
            nodeId: '05', nodeText: 'Downloads', icon: 'folder',
            nodeChild: [
                { nodeId: '05-01', nodeText: 'UI-Guide.pdf', icon: 'pdf' },
                { nodeId: '05-02', nodeText: 'Tutorials.zip', icon: 'zip' },
                { nodeId: '05-03', nodeText: 'Game.exe', icon: 'exe' },
                { nodeId: '05-04', nodeText: 'TypeScript.7z', icon: 'zip' },
            ]
        }
    ]
    
  export let PicDB: { [key: string]: Object }[] = [
        {
            nodeId: '04', nodeText: 'Pictures', icon: 'folder', expanded: true,
            nodeChild: [
                {
                    nodeId: '04-01', nodeText: 'Camera Roll', icon: 'folder', expanded: true,
                    nodeChild: [
                        { nodeId: '04-01-01', nodeText: 'WIN_20160726_094117.JPG', image: 'http://npmci.syncfusion.com/development/demos/src/images/employees/9.png' },
                        { nodeId: '04-01-02', nodeText: 'WIN_20160726_094118.JPG', image: 'http://npmci.syncfusion.com/development/demos/src/images/employees/3.png' },
                    ]
                },
                { nodeId: '04-02', nodeText: 'Wind.jpg', icon: 'images' },
                { nodeId: '04-03', nodeText: 'Stone.jpg', icon: 'images' },
            ]
        }
    ]

import { platformBrowserDynamic } from '@angular/platform-browser-dynamic';
import { enableProdMode } from '@angular/core';
import { AppModule } from './app.module';

enableProdMode();
platformBrowserDynamic().bootstrapModule(AppModule);

<!DOCTYPE html>
<html lang="en">

<head>
    <title>Essential JS 2 Accordion Sample</title>
    <meta charset="utf-8" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <meta name="description" content="Typescript Toolbar Controls" />
    <meta name="author" content="Syncfusion" />
    <link href="index.css" rel="stylesheet" />
    <link href="//cdn.syncfusion.com/ej2/material.css" rel="stylesheet" />

    <script src="https://unpkg.com/core-js/client/shim.min.js"></script>
    <script src="https://cdnjs.cloudflare.com/ajax/libs/core-js/2.4.1/core.min.js"></script>
    <script src="https://cdnjs.cloudflare.com/ajax/libs/zone.js/0.6.25/zone.min.js"></script>
    <script src="https://unpkg.com/reflect-metadata@0.1.3"></script>
    <script src="https://cdnjs.cloudflare.com/ajax/libs/systemjs/0.19.38/system.js"></script>
    <script src="systemjs.config.js"></script>
</head>
<body>
    <app-container>
        <div id='loader'>LOADING....</div>
    </app-container>
</body>
</html>

#container {
    visibility: hidden;
}

#loader {
    color: #008cff;
    height: 40px;
    left: 45%;
    position: absolute;
    top: 45%;
    width: 30%;
}

.accordion-control-section {
    margin: 0 10% 0 10%;
}


.e-treeview .e-list-img {
    width: 25px;
    height: 25px;
}
/* Loading sprite image for TreeView */
.e-treeview .e-list-icon {
    background-repeat: no-repeat;
    background-image: url("./file_icons.png");
    height: 20px;
}
/* Specify the icon positions based upon class name */
/* csslint ignore:start */
.e-treeview .e-list-icon.folder { background-position: -10px -552px }
.e-treeview .e-list-icon.docx { background-position: -10px -20px }
.e-treeview .e-list-icon.ppt { background-position: -10px -48px }
.e-treeview .e-list-icon.pdf { background-position: -10px -104px }
.e-treeview .e-list-icon.images { background-position: -10px -132px }
.e-treeview .e-list-icon.zip { background-position: -10px -188px }
.e-treeview .e-list-icon.audio { background-position: -10px -244px }
.e-treeview .e-list-icon.video { background-position: -10px -272px }
.e-treeview .e-list-icon.exe { background-position: -10px -412px }
/* csslint ignore:end */

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