Customize the expand and collapse icons in Angular TreeView component
27 Aug 202515 minutes to read
The TreeView component displays default expand and collapse icons for parent nodes. These icons can be customized to match application themes or design requirements by using the cssClass property along with custom CSS styling.
The cssClass property allows you to apply custom CSS classes to the TreeView component, which can then be used to override the default expand and collapse icon styles. The TreeView uses specific CSS selectors for these icons that can be targeted through custom CSS rules.
To customize the expand and collapse icons, define custom CSS classes that target the TreeView’s icon elements and apply these styles using the cssClass property. The custom CSS should override the default icon fonts or background images with the desired custom icons.
import { NgModule } from '@angular/core'
import { BrowserModule } from '@angular/platform-browser'
import { FormsModule } from '@angular/forms'
import { TreeViewModule } from '@syncfusion/ej2-angular-navigations'
import { Component, ViewChild } from '@angular/core';
import { TreeViewComponent } from '@syncfusion/ej2-angular-navigations';
@Component({
imports: [
FormsModule, TreeViewModule
],
standalone: true,
selector: 'app-container',
// specifies the template string for the TreeView component
template: `<div id='treeparent'><ejs-treeview id='treeelement' [fields]='field' [cssClass]='cssClass'></ejs-treeview></div>`
})
export class AppComponent {
@ViewChild('samples')
public tree?: TreeViewComponent;
constructor() {
}
// defined the array of data
public hierarchicalData: Object[] = [
{
id: '01', name: 'Local Disk(C:)', expanded: true,
subChild: [
{
id: '01-01', name: 'Program Files',
subChild: [
{ id: '01-01-01', name: '7-Zip' },
{ id: '01-01-02', name: 'Git' },
{ id: '01-01-03', name: 'IIS Express' },
]
},
{
id: '01-02', name: 'Users', expanded: true,
subChild: [
{ id: '01-02-01', name: 'Smith' },
{ id: '01-02-02', name: 'Public' },
{ id: '01-02-03', name: 'Admin' },
]
},
{
id: '01-03', name: 'Windows',
subChild: [
{ id: '01-03-01', name: 'Boot' },
{ id: '01-03-02', name: 'FileManager' },
{ id: '01-03-03', name: 'System32' },
]
},
]
},
{
id: '02', name: 'Local Disk(D:)',
subChild: [
{
id: '02-01', name: 'Personals',
subChild: [
{ id: '02-01-01', name: 'My photo.png' },
{ id: '02-01-02', name: 'Rental document.docx' },
{ id: '02-01-03', name: 'Pay slip.pdf' },
]
},
{
id: '02-02', name: 'Projects',
subChild: [
{ id: '02-02-01', name: 'ASP Application' },
{ id: '02-02-02', name: 'TypeScript Application' },
{ id: '02-02-03', name: 'React Application' },
]
},
{
id: '02-03', name: 'Office',
subChild: [
{ id: '02-03-01', name: 'Work details.docx' },
{ id: '02-03-02', name: 'Weekly report.docx' },
{ id: '02-03-03', name: 'Wish list.csv' },
]
},
]
},
{
id: '03', name: 'Local Disk(E:)', icon: 'folder',
subChild: [
{
id: '03-01', name: 'Pictures',
subChild: [
{ id: '03-01-01', name: 'Wind.jpg' },
{ id: '03-01-02', name: 'Stone.jpg' },
{ id: '03-01-03', name: 'Home.jpg' },
]
},
{
id: '03-02', name: 'Documents',
subChild: [
{ id: '03-02-01', name: 'Environment Pollution.docx' },
{ id: '03-02-02', name: 'Global Warming.ppt' },
{ id: '03-02-03', name: 'Social Network.pdf' },
]
},
{
id: '03-03', name: 'Study Materials',
subChild: [
{ id: '03-03-01', name: 'UI-Guide.pdf' },
{ id: '03-03-02', name: 'Tutorials.zip' },
{ id: '03-03-03', name: 'TypeScript.7z' },
]
},
]
}
];
// maps the appropriate column to fields property
public field: Object = { dataSource: this.hierarchicalData, id: 'id', text: 'name', child: 'subChild' };
// set the Multi Selection option to TreeView
public cssClass: string = "custom";
}@import 'node_modules/@syncfusion/ej2-base/styles/material.css';
@import 'node_modules/@syncfusion/ej2-inputs/styles/material.css';
@import 'node_modules/@syncfusion/ej2-buttons/styles/material.css';
@import 'node_modules/@syncfusion/ej2-angular-base/styles/material.css';
@import 'node_modules/@syncfusion/ej2-angular-navigations/styles/material.css';
@import 'node_modules/@syncfusion/ej2-angular-inputs/styles/material.css';
.custom .e-list-item .e-icons {
font-family: "Customize-icon";
}
.custom.e-treeview .e-list-item div.e-icons.e-icon-expandable::before,
.custom.e-treeview .e-list-item div.e-icons.e-icon-collapsible::before {
content: '\e700';
font-size: 12px;
}
@font-face {
font-family: 'Customize-icon';
src: url(data:application/x-font-ttf;charset=utf-8;base64,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) format('truetype');
font-weight: normal;
font-style: normal;
}
#treeparent {
display: block;
max-width: 400px;
max-height: 330px;
margin: auto;
overflow: auto;
border: 1px solid #dddddd;
border-radius: 3px;
}import { bootstrapApplication } from '@angular/platform-browser';
import { AppComponent } from './app.component';
import 'zone.js';
bootstrapApplication(AppComponent).catch((err) => console.error(err));