How to get the size of a filtered (piped) set in angular2

Question

I wrote my own filter pipe as it disappeared in angular2:

import {Pipe, PipeTransform} from \'angular2/core\';

@Pipe({
  name: \'myFilter\'
})
export class          


        

Answer 1

original

AFAIK there is currently no way to do this directly. A hack would be to add a template variable to the content and use a ViewChildren(...) query to get the created items and count them.

  ...

count: {{filteredItems?.length}}

@ViewChildren('someVar') filteredItems;

An alternative approach would be to pass a reference to a counter variable to the pipe like shown in https://plnkr.co/edit/Eqjyt4qdnXezyFvCcGAL?p=preview

update (Angular >=4.0.0)

Since Angular 4 *ngFor supports as

which you can use in the template (inside the element that *ngFor is added to) like

  
{{result?.length}}