If you take a look at source code then you will see that DatePipe constructor asks for a required parameter: constructor(@Inject(LOCALE_ID) private _locale: string) {} There is no default locale for DataPipe https://github.com/angular/angular/blob/2.0.0/modules/%40angular/common/src/pipes/date_pipe.ts#L97 That’s why typescript gives the error. This way you have to initiate your variable as shown below: datePipeEn: DatePipe = new DatePipe(‘en-US’) … Read more
A pure pipe is only called when Angular detects a change in the value or the parameters passed to a pipe. An impure pipe is called for every change detection cycle no matter whether the value or parameter(s) changes. This is relevant for changes that are not detected by Angular when you pass an array … Read more
Building on borislemke’s answer, here’s a solution which does not need eval() and which I find rather clean: dynamic.pipe.ts: import { Injector, Pipe, PipeTransform } from ‘@angular/core’; @Pipe({ name: ‘dynamicPipe’ }) export class DynamicPipe implements PipeTransform { public constructor(private injector: Injector) { } transform(value: any, pipeToken: any, pipeArgs: any[]): any { if (!pipeToken) { return … Read more
Make sure you are not facing a “cross module” problem If the component which is using the pipe, doesn’t belong to the module which has declared the pipe component “globally” then the pipe is not found and you get this error message. In my case I’ve declared the pipe in a separate module and imported … Read more
In your component’s template you can use multiple arguments by separating them with colons: {{ myData | myPipe: ‘arg1′:’arg2’:’arg3’… }} From your code it will look like this: new MyPipe().transform(myData, arg1, arg2, arg3) And in your transform function inside your pipe you can use the arguments like this: export class MyPipe implements PipeTransform { // … Read more