ionic4-alpha-scroll

Configurable Ionic 2 component for alphabetically indexed list with an alpha scroll bar. This component has a few improvements on the original Ionic 1 component, mainly the panning functionality on the alpha wheel scroll shown below in the demo.

Installation

1. Use npm to install the component

npm install ionic4-alpha-scroll --save

1. Add the ionic4-alpha-scroll component to your app.

Include the following on your src/app/app.module.ts.

import { IonAlphaScrollModule } from 'ionic4-alpha-scroll';

@NgModule({
  declarations: [
    MyApp,
    ...
  ],
  imports: [
    IonicModule.forRoot(MyApp),
    IonAlphaScrollModule
  ],
  ...
})

KNOWN ISSUE - I cannot get AoT compiling to work currently. I am looking into how to make this possible with the Ionic 2.0.0 stable release. If anyone knows how to make it compatible with AoT please submit a pull request.

This means you cannot run ionic build ios --prod because that will use AoT compiling. Unfortunately you will have to use ionic build ios and omit the AoT compiling to use this component.

Demo

Here is a sample Ionic 2 app on GitHub that shows how to use this component

Usage

To use the ion-alpha-scroll component add this below to the <ion-content> in your template:

<ion-alpha-scroll *ngIf="breeds"
  [listData]="breeds"
  key="name"
  [itemTemplate]="alphaScrollItemTemplate"
  [currentPageClass]="currentPageClass"
  [triggerChange]="triggerAlphaScrollChange">
</ion-alpha-scroll>

• listData is the model you would like to sort. Use an array of objects here.
• key is the name of the key you would like to sort by.
• itemTemplate is the template to display for the properties of each item in the model.
• currentPageClass is a reference to the instance of the current current page class (see example below). This is needed so that bindings on the itemTemplate can refer to the Ionic 2 page class containing the ion-alpha-scroll.
• triggerChange can be any property you want that can be changed to trigger ngOnChange for the ion-alpha-scroll component. If listData was modified the alpha list will reflect that after triggering the change.

Heres a quick example:

@Component({
  selector: 'alpha-list-page',
  template: `
    <ion-header>
      <ion-navbar>
        <ion-title>Dog Breeds</ion-title>
      </ion-navbar>
    </ion-header>

    <ion-content class="alpha-list-page">
      <ion-alpha-scroll *ngIf="breeds"
        [listData]="breeds"
        key="name"
        [itemTemplate]="alphaScrollItemTemplate"
        [currentPageClass]="currentPageClass"
        [triggerChange]="triggerAlphaScrollChange">
      </ion-alpha-scroll>
    </ion-content>
  `
})
export class AlphaListPage {
  breeds: any;
  currentPageClass = this;
  alphaScrollItemTemplate: string = `
    <ion-item (click)="currentPageClass.onItemClick(item)">
      {{item.name}}
    </ion-item>
  `;
  triggerAlphaScrollChange: number = 0;

  constructor() {
    this.assignBreeds();
  }

  onItemClick(item) {
    // This is an example of how you could manually trigger ngOnChange
    // for the component. If you modify "listData" it won't perform
    // an ngOnChange, you will have to trigger manually to refresh the component.
    this.triggerAlphaScrollChange++;
  }

  assignBreeds() {
    this.breeds = [
      {
        'name': 'Affenpinscher'
      },
      {
        'name': 'Afghan Hound'
      },
      // ...
    ];
  }

  // ...
}

If you would like to disable the scroll bar for the ion-alpha-scroll scroll-content use this CSS:

.ion-alpha-scroll .scroll-content::-webkit-scrollbar {
  display: none;
}

Acknowledgements

https://github.com/aquint/ion-alpha-scroll

License

MIT