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In this guide, we will discuss Ngx-Bootstrap – Alerts.

Alerts provide contextual messages for typical user actions like info, error with available and flexible alert messages.

AlertComponent

Displays collapsible content panels for presenting information in a limited amount of space.

selector

• alert,bs-alert

Inputs

• dismissible − boolean, If set, displays an inline “Close” button, default: false
• dismissOnTimeout − string | number, Number in milliseconds, after which alert will be closed
• isOpen − boolean, Is alert visible, default: true
• type − string, alert type. Provides one of four bootstrap supported contextual classes: success, info, warning and danger, default: warning

Outputs

• onClose − This event fires immediately after close instance method is called, $event is an instance of Alert component.
• onClosed − This event fires when alert closed, $event is an instance of Alert component

AlertConfig

Properties

• dismissible − boolean, is alerts are dismissible by default, default: false
• dismissOnTimeout − number, default time before alert will dismiss, default: undefined
• type − string, default alert type, default: warning

Example

As we’re going to use alerts, We’ve to update app.module.ts used in the ngx-bootstrap Accordion chapter to use AlertModule and AlertConfig.

Update app.module.ts to use the AlertModule and AlertConfig.

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

Update test.component.html to use the alerts.

test.component.html

<alert type="success" 
   [dismissible]="dismissible"
   [isOpen]="open"
   (onClosed)="log($event)"
   [dismissOnTimeout]="timeout">
   <h4 class="alert-heading">Well done!</h4>
   <p>Success Message</p>
</alert>
<alert type="info">
   <strong>Heads up!</strong> Info
</alert>
<alert type="warning">
   <strong>Warning!</strong> Warning
</alert>
<alert type="danger">
   <strong>Oh snap!</strong> Error
</alert>

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 {
   open: boolean = true;
   dismissible: boolean = true;
   timeout: number = 10000;
   constructor() { }
   
   ngOnInit(): void {
   }
   log(alert){
      console.log('alert message closed');
   }
}

Build and Serve

Run the following command to start the Angular server.

ng serve

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

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