Angular - Transforming Data with Pipes

Sometimes we need to transform bound properties before it is displayed. Such is the case with formatting dates, currency, decimals, etc. Pipes can be chained.

Built-in Pipes

• date
• number, decimal, percent, currency
• json, slice, etc

The complete list and more information can be found here.

Examples (no parameters):

{{ product.productCode | lowercase }}

<img [src]='product.imageUrl' [title]='product.productName | uppercase'>

{{ product.price | currency | lowercase }}

Examples (with parameters)

NOTE: Parameters are separated by colons

{{ product.price | currency: 'USD' : true : '1.2-2' }}

Custom Pipe

import { Pipe, PipeTransform } from '@angular/core';

@Pipe({name: 'myTransform'})

export class MyTransform implements PipeTransform {

     transform(value: string, customParam1: string): string { ... }

}

Add it to your module (i.e. app.module.ts) as shown here:

@NgModule({

imports: ...

declarations: [ AppComponent, MyTransform ],

bootstrap: ...

})

Use it just like the built in pipes