InfiniteScroll

ion-infinite-scroll

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The Infinite Scroll allows you to perform an action when the user scrolls a specified distance from the bottom or top of the page.

The expression assigned to the infinite event is called when the user scrolls to the specified distance. When this expression has finished its tasks, it should call the complete() method on the infinite scroll instance.

Usage

<ion-content>

 <ion-list>
   <ion-item *ngFor="let i of items">{{i}}</ion-item>
 </ion-list>

 <ion-infinite-scroll (ionInfinite)="doInfinite($event)">
   <ion-infinite-scroll-content></ion-infinite-scroll-content>
 </ion-infinite-scroll>

</ion-content>

@Component({...})
export class NewsFeedPage {
  items = [];

  constructor() {
    for (let i = 0; i < 30; i++) {
      this.items.push( this.items.length );
    }
  }

  doInfinite(infiniteScroll) {
    console.log('Begin async operation');

    setTimeout(() => {
      for (let i = 0; i < 30; i++) {
        this.items.push( this.items.length );
      }

      console.log('Async operation has ended');
      infiniteScroll.complete();
    }, 500);
  }

}

waitFor method of InfiniteScroll

In case if your async operation returns promise you can utilize waitFor method inside your template.

<ion-content>

 <ion-list>
   <ion-item *ngFor="let item of items"></ion-item>
 </ion-list>

 <ion-infinite-scroll (ionInfinite)="$event.waitFor(doInfinite())">
   <ion-infinite-scroll-content></ion-infinite-scroll-content>
 </ion-infinite-scroll>

</ion-content>

@Component({...})
export class NewsFeedPage {
  items = [];

  constructor() {
    for (var i = 0; i < 30; i++) {
      this.items.push( this.items.length );
    }
  }

  doInfinite(): Promise<any> {
    console.log('Begin async operation');

    return new Promise((resolve) => {
      setTimeout(() => {
        for (var i = 0; i < 30; i++) {
          this.items.push( this.items.length );
        }

        console.log('Async operation has ended');
        resolve();
      }, 500);
    })
  }
}

Infinite Scroll Content

By default, Ionic uses the infinite scroll spinner that looks best for the platform the user is on. However, you can change the default spinner or add text by adding properties to the ion-infinite-scroll-content component.

<ion-content>

  <ion-infinite-scroll (ionInfinite)="doInfinite($event)">
    <ion-infinite-scroll-content
      loadingSpinner="bubbles"
      loadingText="Loading more data...">
    </ion-infinite-scroll-content>
  </ion-infinite-scroll>

</ion-content>

Further Customizing Infinite Scroll Content

The ion-infinite-scroll component holds the infinite scroll logic. It requires a child component in order to display the content. Ionic uses ion-infinite-scroll-content by default. This component displays the infinite scroll and changes the look depending on the infinite scroll's state. Separating these components allows developers to create their own infinite scroll content components. You could replace our default content with custom SVG or CSS animations.

Instance Members

complete()

Call complete() within the infinite output event handler when your async operation has completed. For example, the loading state is while the app is performing an asynchronous operation, such as receiving more data from an AJAX request to add more items to a data list. Once the data has been received and UI updated, you then call this method to signify that the loading has completed. This method will change the infinite scroll’s state from loading to enabled.

enable(shouldEnable)

Call enable(false) to disable the infinite scroll from actively trying to receive new data while scrolling. This method is useful when it is known that there is no more data that can be added, and the infinite scroll is no longer needed.

waitFor()

Pass a promise inside waitFor() within the infinite output event handler in order to change state of infiniteScroll to “complete”

Input Properties

Output Events

Sass Variables