Angular filter for last element

Question

How can I write a filter , which only returns the last element of a list / how can I write a filter which returns all but the last element.

Background: I'm having a list of items, where the last item should be editable. Therefor I need this filter to get it.

Answer 1

You could use a Pipe to filter an array

pipe

@Pipe({name: 'lastItem'})
export class LastItemPipe implements PipeTransform {
  transform(items: any[], exclusive: boolean): any {
    if (exclusive) { return items.slice(0, items.length - 1); }
    return [items[items.length - 1]];
  }
}

template

<h2>list without</h2>    
<div *ngFor="let item of items | lastItem:true">{{item}}</div>    
<h2>list with</h2>    
<div *ngFor="let item of items | lastItem:false">{{item}}</div>

Live plunker example