How to create a pipe to format account numbers?-CodePudding

Is there an expert in Angular, who can take the time to explain to me how one can create a pipe to format the account number?

The account number always has a mandatory length of 12 digits.

For example => 123456789123

The variable retrieved from the webService is of type number.
I would like to get this type of display

123-4567891-23
458-4698712-15
etc...

I'm still too beginner to figure out how I should create this. Would someone be kind enough to help me create the pipe, so I can understand.

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

@Pipe({
  name: 'accountDash'
})
export class AccountDashPipe implements PipeTransform {
  transform(): any {
    return;
  }
}

Thank you for your help, I apologize if my message is too light.

CodePudding user response：

You can convert the number to a string and format it quite easily

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

@Pipe({
  name: 'accountDash'
})
export class AccountDashPipe implements PipeTransform {
  transform(accountNumber: Number): string {
    return String(accountNumber).replace(/^(\d{3})(\d{7})(\d{2})$/, `$1-$2-$3`)
  }
}

All you need to do is then apply it to your template.

<span>{{someAccountNumber|accountDash}}</span>

You may or may not want to add some error handling in the pipe to detect if it is attempting to consume an invalid account number.

StackBlitz

CodePudding user response：

To create a pipe to format account numbers in Angular, you will need to create a new file in your project's "pipes" directory with the desired name for your pipe (e.g. "account-number.pipe.ts").

In this file, you will need to import the necessary modules, such as the Pipe and PipeTransform interfaces from the @angular/core module. You will also need to define the pipe's metadata using the @Pipe decorator, and implement the PipeTransform interface to define the transform() method.

Here is an example of how to create a pipe to format account numbers in Angular:

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

@Pipe({
  name: 'accountNumber'
})
export class AccountNumberPipe implements PipeTransform {
  transform(value: string): string {
    if (!value) {
      return '';
    }
    let formattedAccountNumber = '';
    for (let i = 0; i < value.length; i  ) {
      if (i % 4 === 0 && i !== 0) {
        formattedAccountNumber  = '-';
      }
      formattedAccountNumber  = value[i];
    }
    return formattedAccountNumber;
  }
}

In this example, the pipe's name is "accountNumber" and it takes in a string value representing the account number. The transform() method checks if the value is empty and returns an empty string if it is. Otherwise, it loops through the characters in the value and adds a dash (-) every fourth character. It then returns the formatted account number.

You will also need to add this pipe to your module's declarations array so that it can be used in your templates.

import { AccountNumberPipe } from './pipes/account-number.pipe';

@NgModule({
  declarations: [
    AccountNumberPipe
  ]
  // ...

Once the pipe is created, you can use it in your templates by calling the pipe in your template's expressions.

{{ accountNumber | accountNumber }}

This will format the accountNumber variable in the format of "xxxx-xxxx-xxxx-xxxx"