In AngularJS, I am able to use filters (pipes) inside of services and controllers using syntax similar to this:
$filter('date')(myDate, 'yyyy-MM-dd');
Is it possible to use pipes in services/components like this in Angular?
391
votes
8 Answers
762
votes
As usual in Angular, you can rely on dependency injection:
import { DatePipe } from '@angular/common';
class MyService {
constructor(private datePipe: DatePipe) {}
transformDate(date) {
return this.datePipe.transform(date, 'yyyy-MM-dd');
}
}
Add DatePipe to your providers list in your module; if you forget to do this you'll get an error no provider for DatePipe:
providers: [DatePipe,...]
Update Angular 6: Angular 6 now offers pretty much every formatting functions used by the pipes publicly. For example, you can now use the formatDate function directly.
import { formatDate } from '@angular/common';
class MyService {
constructor(@Inject(LOCALE_ID) private locale: string) {}
transformDate(date) {
return formatDate(date, 'yyyy-MM-dd', this.locale);
}
}
Before Angular 5: Be warned though that the DatePipe was relying on the Intl API until version 5, which is not supported by all browsers (check the compatibility table).
If you're using older Angular versions, you should add the Intl polyfill to your project to avoid any problem.
See this related question for a more detailed answer.
83
votes
This answer is now outdated
recommend using DI approach from other answers instead of this approach
Original answer:
You should be able to use the class directly
new DatePipe().transform(myDate, 'yyyy-MM-dd');
For instance
var raw = new Date(2015, 1, 12);
var formatted = new DatePipe().transform(raw, 'yyyy-MM-dd');
expect(formatted).toEqual('2015-02-12');
22
votes
Yes, it is possible by using a simple custom pipe. Advantage of using custom pipe is if we need to update the date format in future, we can go and update a single file.
import { Pipe, PipeTransform } from '@angular/core';
import { DatePipe } from '@angular/common';
@Pipe({
name: 'dateFormatPipe',
})
export class dateFormatPipe implements PipeTransform {
transform(value: string) {
var datePipe = new DatePipe("en-US");
value = datePipe.transform(value, 'MMM-dd-yyyy');
return value;
}
}
{{currentDate | dateFormatPipe }}
You can always use this pipe anywhere , component, services etc
For example:
export class AppComponent {
currentDate : any;
newDate : any;
constructor(){
this.currentDate = new Date().getTime();
let dateFormatPipeFilter = new dateFormatPipe();
this.newDate = dateFormatPipeFilter.transform(this.currentDate);
console.log(this.newDate);
}
Don't forget to import dependencies.
import { Component } from '@angular/core';
import {dateFormatPipe} from './pipes'
19
votes
Other answers don't work in angular 5?
I got an error because DatePipe is not a provider, so it cannot be injected. One solution is to put it as a provider in your app module but my preferred solution was to instantiate it.
Instantiate it where needed:
I looked at DatePipe's source code to see how it got the locale: https://github.com/angular/angular/blob/5.2.5/packages/common/src/pipes/date_pipe.ts#L15-L174
I wanted to use it within a pipe, so my example is within another pipe:
import { Pipe, PipeTransform, Inject, LOCALE_ID } from '@angular/core';
import { DatePipe } from '@angular/common';
@Pipe({
name: 'when',
})
export class WhenPipe implements PipeTransform {
static today = new Date((new Date).toDateString().split(' ').slice(1).join(' '));
datePipe: DatePipe;
constructor(@Inject(LOCALE_ID) private locale: string) {
this.datePipe = new DatePipe(locale);
}
transform(value: string | Date): string {
if (typeof(value) === 'string')
value = new Date(value);
return this.datePipe.transform(value, value < WhenPipe.today ? 'MMM d': 'shortTime')
}
}
The key here is importing Inject, and LOCALE_ID from angular's core, and then injecting that so you can give it to the DatePipe to instantiate it properly.
Make DatePipe a provider
In your app module you could also add DatePipe to your providers array like this:
import { DatePipe } from '@angular/common';
@NgModule({
providers: [
DatePipe
]
})
Now you can just have it injected in your constructor where needed (like in cexbrayat's answer).
Summary:
Either solution worked, I don't know which one angular would consider most "correct" but I chose to instantiate it manually since angular didn't provide datepipe as a provider itself.
12
votes
If you don't want do new myPipe() because you're injecting dependencies to pipe, you can inject in component like provider and use without new.
Example:
// In your component...
import { Component, OnInit } from '@angular/core';
import { myPipe} from './pipes';
@Component({
selector: 'my-component',
template: '{{ data }}',
providers: [ myPipe ]
})
export class MyComponent() implements OnInit {
data = 'some data';
constructor(private myPipe: myPipe) {}
ngOnInit() {
this.data = this.myPipe.transform(this.data);
}
}
11
votes
10
votes
As of Angular 6 you can import formatDate from @angular/common utility to use inside the components.
It was intruduced at https://github.com/smdunn/angular/commit/3adeb0d96344c15201f7f1a0fae7e533a408e4ae
I can be used as:
import {formatDate} from '@angular/common';
formatDate(new Date(), 'd MMM yy HH:mm', 'en');
Although the locale has to be supplied
6
votes
You can use formatDate() to format the date in services or component ts. syntax:-
formatDate(value: string | number | Date, format: string, locale: string, timezone?: string): string
import the formatDate() from common module like this,
import { formatDate } from '@angular/common';
and just use it in the class like this ,
formatDate(new Date(), 'MMMM dd yyyy', 'en');
You can also use the predefined format options provided by angular like this ,
formatDate(new Date(), 'shortDate', 'en');
You can see all other predefined format options here ,
