PipeTransform
interface
To create a Pipe, you must implement this interface.
interface PipeTransform {
  transform(value: any, ...args: any[]): any
} Class implementations
Description
Angular invokes the transform method with the value of a binding as the first argument, and any parameters as the second argument in list form.
Methods
|   transform()    | ||||||
|---|---|---|---|---|---|---|
| 
 | 
| value | any | |
| args | any[] | 
Returns
any
Usage notes
Example
The RepeatPipe below repeats the value as many times as indicated by the first argument:
import {Pipe, PipeTransform} from '@angular/core';
@Pipe({name: 'repeat'})
export class RepeatPipe implements PipeTransform {
  transform(value: any, times: number) {
    return value.repeat(times);
  }
} Invoking {{ 'ok' | repeat:3 }} in a template produces okokok.
    © 2010–2019 Google, Inc.
Licensed under the Creative Commons Attribution License 4.0.
    https://v7.angular.io/api/core/PipeTransform