Angular PrimeNG Form TreeSelect Events
Angular PrimeNG is an open-source library that consists of native Angular UI components that are used for great styling and this framework is used to make responsive websites with very much ease. In this article, we will be seeing the Angular PrimeNG Form TreeSelect Events.
The TreeSelect Component allows the users to select items from hierarchical data. It accepts an array of TreeNodes as its options property to show the data.
Angular PrimeNG Form TreeSelect Events:
- onShow: When the overlay is shown, a callback is triggered.
- onHide: When the overlay is hidden, a callback is triggered.
- onFilter: When the data is filtered, a callback is triggered.
- onNodeSelect: When the node is selected, a callback is triggered.
- onNodeUnselect: When the node is unselected, a callback is triggered.
- onNodeExpand: When the node is expanded, a callback is triggered.
- onNodeCollapse: When the node is collapsed, a callback is triggered.
- onClear: When an input field is cleared, a callback is triggered.
Syntax:
<p-treeSelect (event)=function()> </p-treeSelect>
Creating Angular application & module installation:
Step 1: Create an Angular application using the following command.
ng new appname
Step 2: After creating your project folder i.e. appname, move to it using the following command.
cd appname
Step 3: Install PrimeNG in your given directory.
npm install primeng --save npm install primeicons --save
Project Structure: It will look like the following
Steps to run the application: Run the below command to see the output
ng serve --save
Example 1: In this example, we will learn about Angular PrimeNG Form TreeSelect Events onNodeExpand.
- app.component.html:
HTML
< h1 style = "color: green;" >w3wiki</ h1 > < h2 >Angular PrimeNG Form TreeSelect Events</ h2 > < p-treeSelect [(ngModel)]="selected" selectionMode = "single" [options]="nodes" placeholder = "Select a Node" (onNodeExpand)="onNodeExpand()"> </ p-treeSelect > |
- app.component.ts:
Javascript
import { Component } from "@angular/core" ; import { TreeNode } from "primeng/api" ; @Component({ selector: "app-root" , templateUrl: "./app.component.html" }) export class AppComponent { nodes: TreeNode[] = []; selected: any; onNodeExpand() { alert( "Node is Expanded" ); } ngOnInit() { this .nodes = [ { label: "Work" , icon: "pi pi-folder" , children: [ { label: "data.json" , icon: "pi pi-file" }, { label: "sales.docx" , icon: "pi pi-file" }, { label: "presentation.pptx" , icon: "pi pi-file" } ] }, { label: "Home" , icon: "pi pi-folder" , children: [ { label: "grocery.word" , icon: "pi pi-file" }, { label: "picture.jpeg" , icon: "pi pi-file" }, { label: "homeplan.png" , icon: "pi pi-file" } ] }, { label: "Multimedia" , icon: "pi pi-folder" , children: [ { label: "infinity-war.mp4" , icon: "pi pi-file" }, { label: "you.mp3" , icon: "pi pi-file" }, { label: "endgame.mp4" , icon: "pi pi-file" }, { label: "MI.mp4" , icon: "pi pi-file" } ] } ]; } } |
- app.module.ts:
Javascript
import { NgModule } from "@angular/core" ; import { BrowserAnimationsModule } from "@angular/platform-browser/animations" ; import { AppComponent } from "./app.component" ; import { FormsModule } from "@angular/forms" ; import { TreeSelectModule } from "primeng/treeselect" ; @NgModule({ imports: [ BrowserAnimationsModule, TreeSelectModule, FormsModule ], declarations: [AppComponent], bootstrap: [AppComponent] }) export class AppModule {} |
Output:
Example 2: In this example, we will learn about Angular PrimeNG Form TreeSelect Events onNodeCollapse.
- app.component.html:
HTML
< h1 style = "color:green" >w3wiki</ h1 > < h2 >Angular PrimeNG Form TreeSelect Events</ h2 > < p-treeSelect [(ngModel)]="selected" selectionMode = "single" [options]="nodes" placeholder = "Select a Node" (onNodeCollapse)=onNodeCollapse()> </ p-treeSelect > |
- app.component.ts:
Javascript
import { Component } from "@angular/core" ; import { TreeNode } from "primeng/api" ; @Component({ selector: "app-root" , templateUrl: "./app.component.html" , }) export class AppComponent { nodes: TreeNode[] = []; selected: any; onNodeCollapse(){ alert( "Node is Collapsed" ) } ngOnInit() { this .nodes = [ { "label" : "Work" , "icon" : "pi pi-folder" , "children" : [ { "label" : "data.json" , "icon" : "pi pi-file" }, { "label" : "sales.docx" , "icon" : "pi pi-file" }, { "label" : "presentation.pptx" , "icon" : "pi pi-file" } ] }, { "label" : "Home" , "icon" : "pi pi-folder" , "children" : [ { "label" : "grocery.word" , "icon" : "pi pi-file" }, { "label" : "picture.jpeg" , "icon" : "pi pi-file" }, { "label" : "homeplan.png" , "icon" : "pi pi-file" } ] }, { "label" : "Multimedia" , "icon" : "pi pi-folder" , "children" : [ { "label" : "infinity-war.mp4" , "icon" : "pi pi-file" }, { "label" : "you.mp3" , "icon" : "pi pi-file" }, { "label" : "endgame.mp4" , "icon" : "pi pi-file" }, { "label" : "MI.mp4" , "icon" : "pi pi-file" } ] } ]; } } |
- app.module.ts:
Javascript
import { NgModule } from "@angular/core" ; import { BrowserAnimationsModule } from "@angular/platform-browser/animations" ; import { AppComponent } from "./app.component" ; import { FormsModule } from "@angular/forms" ; import { TreeSelectModule } from "primeng/treeselect" ; @NgModule({ imports: [ BrowserAnimationsModule, TreeSelectModule, FormsModule ], declarations: [AppComponent], bootstrap: [AppComponent] }) export class AppModule {} |
Output:
Reference: https://primefaces.org/primeng/treeselect
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