ngx-bootstrap Collapse directive helps to show/hide a container content.

CollapseDirective

selector

• [collapse]

Inputs

• collapse − boolean, A flag indicating visibility of content (shown or hidden)

• display − string

• isAnimated − boolean, turn on/off animation. default: false

Outputs

• collapsed − This event fires as soon as content collapses

• collapses − This event fires when collapsing is started

• expanded − This event fires as soon as content becomes visible

• expands − This event fires when expansion is started

Methods

• toggle() − allows to manually toggle content visibility

• hide − allows to manually hide content

• show − allows to manually show collapsed content

Example

As we”re going to use collapse, We”ve to update app.module.ts used in ngx-bootstrap Carousel chapter to use CollapseModule.

Update app.module.ts to use the CollapseModule.

app.module.ts

import { BrowserModule } from ''@angular/platform-browser'';
import { NgModule } from ''@angular/core'';
import { BrowserAnimationsModule } from ''@angular/platform-browser/animations'';
import { AppComponent } from ''./app.component'';
import { TestComponent } from ''./test/test.component'';
import { AccordionModule } from ''ngx-bootstrap/accordion'';
import { AlertModule,AlertConfig } from ''ngx-bootstrap/alert'';
import { ButtonsModule } from ''ngx-bootstrap/buttons'';
import { FormsModule } from ''@angular/forms'';
import { CarouselModule } from ''ngx-bootstrap/carousel'';
import { CollapseModule } from ''ngx-bootstrap/collapse'';

@NgModule({
   declarations: [
      AppComponent,
      TestComponent
   ],
   imports: [
      BrowserAnimationsModule,
      BrowserModule,
      AccordionModule,
      AlertModule,
      ButtonsModule,
      FormsModule,
      CarouselModule,
      CollapseModule
   ],
   providers: [AlertConfig],
   bootstrap: [AppComponent]
})
export class AppModule { }

Update test.component.html to use the Collapse.

test.component.html

<div>
   <div class="checkbox">
      <label><input type="checkbox" [(ngModel)]="isCollapsed">Collapse</label>
   </div>
</div>
<div [collapse]="isCollapsed" [isAnimated]="true">
   <div class="well well-lg card card-block card-header">Welcome to Tutorialspoint.</div>
</div>

Update test.component.ts for corresponding variables and methods.

test.component.ts

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

@Component({
   selector: ''app-test'',
   templateUrl: ''./test.component.html'',
   styleUrls: [''./test.component.css'']
})
export class TestComponent implements OnInit {
   isCollapsed: boolean = false;
   constructor() { }

   ngOnInit(): void {
   }
}

Build and Serve

Run the following command to start the angular server.

ng serve

Once server is up and running. Open http://localhost:4200 and verify the following output.

Check the collapse check box and then content will be collapsed.