Creating a custom pipe | split() | Angular

Pipes are a great way to manipulate data in a template. Out of the box, we get pipes for a date, currency and etc.


But there is always a situation occurs where you need to create your own custom pipes.


In my case, I needed to split tracking_number which was in a format like: 10001-TY778899 (user id-package id)


Now, I could serialize package_id alone in the backend, but, let's face it. I was too lazy for that. So I had to do it in the frontend.


Let's come to the actual part.

Step 1: Create a pipe template and name it split

ng g pipe pipes/split

We will have this template:

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

@Pipe({
  name: 'split'
})
export class SplitPipe implements PipeTransform {

  transform(value: unknown, ...args: unknown[]): unknown {
    return null;
  }
}

Change parameters and write the code that splits string.

Example use case

we have text argument which is the text in a template

{{ this is where we'll split | split: " " }}

I tried to split by space in the above example.

The Code

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

@Pipe({
  name: 'split'
})
export class SplitPipe implements PipeTransform {

  transform(text: string, by: string, index: number = 1) {
    let arr = text.split(by); // split text by "by" parameter
    return arr[index] // after splitting to array return wanted index
  }
}

Now, about that tracking_number, I needed the right part of 10001-TY778899 after splitting by - (hyphen) so in my case, I set default index number 1 hoping that I will get TY778899 which I actually did!

Use Case

Before:

<tr *ngFor="let p of user.stored_packages" (click)="package = p">
    <td>{{ p.id }}</td>
    <td>{{ p.tracking_number | split: "-" }}</td>
    <td>{{ p.courier_id }}</td>
</tr>

After:

If you ever need particular index, keep in mind that you can use it like this

<td>{{ p.tracking_number | split: "-": 0 }}</td>

Well, this was a simple custom pipe example in Angular

---

If you are interested in Django, Vue.js too, I invite you to check out these projects that I made with love ❤

Kenan7 / corvento_backend

Check out the frontend part that I wrote in Vue.js https://github.com/Kenan7/corvento_frontend

Corvento Backend

You can check out the Corvento Frontend written in Vue.js

Also see Corvento mobile app that my friend wrote in Flutter

Models Graph --> Only used apps

Models Graph --> All

View on GitHub

Kenan7 / corvento_frontend

All online events in one place during the pandemic

corvento-frontend

Project setup

npm install

Compiles and hot-reloads for development

npm run serve

Compiles and minifies for production

npm run build

Lints and fixes files

npm run lint

Customize configuration

See Configuration Reference.

View on GitHub