Angular Material Select Infinite Scroll

Adds missing infinite scroll functionality for the Angular Material Select component.

Inputs

| Property | Description | Type | Default |
| -------------- | ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | ----------| ---------- |
| complete | If true, the infiniteScroll output will no longer be triggered. | boolean | false |
| threshold | The threshold distance from the bottom of the options list to call the infiniteScroll output event when scrolled. The threshold value can be either in percent or pixels. For example, 10% triggers the event 10% before the bottom. | string | '15%' |
| debounceTime | The threshold time (in milliseconds) before firing the infiniteScroll event. | number | 150 |

Outputs

| Property | Description | Type |
| ----------------- | --------------------------------------------------------------------------------------- | --------------------- |
| infiniteScroll | Emitted when the scroller inside the mat-select reaches the required distance. | EventEmitter<void> |

Installation

npm i ng-mat-select-infinite-scroll

Usage

StackBlitz working example

Import MatSelectInfiniteScrollModule inside the app.module.ts:

import { MatFormFieldModule } from '@angular/material/form-field';
import { MatSelectModule } from '@angular/material/select';
import { MatSelectInfiniteScrollModule } from 'ng-mat-select-infinite-scroll';

@NgModule({
  declarations: [
    AppComponent
  ],
  imports: [
    BrowserModule,
    BrowserAnimationsModule,
    MatFormFieldModule,
    MatSelectModule,
    MatSelectInfiniteScrollModule
  ],
  providers: [],
  bootstrap: [AppComponent]
})
export class AppModule {}

Then, place the msInfiniteScroll directive on the mat-select component:

<mat-form-field appearance="outline">
  <mat-label>Select</mat-label>
  <mat-select msInfiniteScroll (infiniteScroll)="getNextBatch()" [complete]="offset === data.length">
    <mat-option *ngFor="let option of options$ | async" [value]="option">{{option}}</mat-option>
  </mat-select>
</mat-form-field>

Note:
Update the complete property when the loaded data reaches the total available data to avoid unnecessary scroll triggers.
For older versions of Angular (<15), use version 4 of this library.

Compatibility

This library supports Angular 15 and higher.

• @angular/core: >=15.0.0 <16
• @angular/cdk: >=15.0.0 <16
• @angular/material: >=15.0.0 <16
• rxjs: ^7.0.0

Contributions

Contributions are welcome! Feel free to open a Pull Request or create a new issue.

Development Server

Run ng serve for a dev server. Navigate to http://localhost:4200/. The app will automatically reload if you change any source files.

Build

Run ng build to build the project. The build artifacts will be stored in the dist/ directory. Use the --prod flag for a production build.

Running Unit Tests

Run ng test to execute unit tests via Karma.

License

MIT