Eag/Banger

A library for bank account validation. Now with badges!

Introduction

Validating user inputs can be a nightmare. Bank account validation used to be one of the worst cases since there are many formats and algorithms you have to implement. But not anymore - say hello to Banger!

Instalation

You can't install this library quite yet, though it will hopefully be published to packagist and ready to install via composer soon.

composer require eag/banger # Right now you have to imagine this works.

Requirements

This library requires PHP 8.0 or later and BCMath extension for some specific algorithms.

Features

All features of this library were made possible via a set of classes implementing BankAccountValidator interface. You can use them directly or wrap one or more in an aggregator class.

use Eag\Banger\Validator\NationalBankAccountValidator;
use Eag\Banger\Validator\NationalBankAccountValidator\CzechBankAccountValidator;

/** @var NationalBankAccountValidator $validator */
$validator = new CzechBankAccountValidator();

Validating a bank account

There are two ways - either use specific national bank account validator, or use a subset of implemented bank account validators.

Validate bank accounts for a single specific country

This way is perfect if you want an easy and simple solution for validating one specific country and nothing else.

use Eag\Banger\Validator\NationalBankAccountValidator;
use Eag\Banger\Validator\NationalBankAccountValidator\CzechBankAccountValidator;

/** @var NationalBankAccountValidator $validator */
$validator = new CzechBankAccountValidator();

try {
    $validator->validate('705-77628031/0710');
} catch (\Eag\Banger\Exception\InvalidBankAccountNumber){
    // Ooops, that doesn't seem to be a valid Czech bank account number
}

// We've got a valid Czech bank account number

Validate multiple bank accounts

use Eag\Banger\Validator\BankAccountValidator;
use Eag\Banger\Validator\NationalBankAccountValidator;
use Eag\Banger\Validator\PhpBankAccountValidator;

/** 
 * An array of validators for each country whose bank accounts you want to validate. 
 * @var NationalBankAccountValidator[] $validators 
 */
$validators = [
    new CzechBankAccountValidator(),
    new HawaiianBankAccountValidator(),
    ...
];

/** @var BankAccountValidator $validator */
$validator = new PhpBankAccountValidator($validators);
try {
    $validator->validate('705-77628031/0710', 'CZE');
} catch (\Eag\Banger\Exception\InvalidBankAccountNumber){
    // Ooops, that doesn't seem to be a valid Czech bank account number
}

// We've got a valid Czech bank account number

Determining bank accounts country

Maybe you have noticed you need to know the bank account's country to validate it. Sometimes you already know that and want to validate a bank account for a specific country and sometimes you don't really care that much and just want to know it's valid - BankAccountCountryDeterminer to the rescue!

Determine bank account country

A determiner is your friend when you want to know the country of a bank account.

use Eag\Banger\Determiner\BankAccountCountryDeterminer;
use Eag\Banger\Determiner\PhpBankAccountCountryDeterminer;
use Eag\Banger\Validator\NationalBankAccountValidator;

/** 
 * An array of validators for each country you wish to determine. 
 * @var NationalBankAccountValidator[] $validators 
 */
$validators = [
    new CzechBankAccountValidator(),
    new HawaiianBankAccountValidator()
];

/** @var BankAccountCountryDeterminer $determiner */
$determiner = new PhpBankAccountCountryDeterminer($validators);

echo $determiner->determine('705-77628031/0710'); // CZE
echo $determiner->determine('123431'); // throws UnknownBankAccountCountry exception

Validate bank account from unknown country

Combine with a BankAccountValidator to validate bank account whose country you don't know.

use Eag\Banger\Determiner\BankAccountCountryDeterminer;
use Eag\Banger\Determiner\PhpBankAccountCountryDeterminer;
use Eag\Banger\Validator\BankAccountValidator;
use Eag\Banger\Validator\PhpBankAccountValidator;

$bankAccountNumber = '705-77628031/0710';

$validators = [...];
/** @var BankAccountCountryDeterminer $determiner */
$determiner = new PhpBankAccountCountryDeterminer($validators);
/** @var BankAccountValidator $validator */
$validator = new PhpBankAccountValidator($validators);

try {
    $validator->validate($bankAccountNumber, $determiner->determine($bankAccountNumber));
} catch (\Eag\Banger\Exception\InvalidBankAccountNumber){
    // Ooops, that doesn't seem to be a valid bank account number
}

// We've got a valid bank account number

FAQ

Why don't you just give me a single simple class that validates all bank accounts?

There are two main reasons:

1. This way you can use your own implementations of NationalBankAccountValidator when it is not implemented yet or the current implementation doesn't meet your expectations.
2. We didn't implement all validators just yet. Every time we would add a new validator we would also introduce a breaking change to existing codebases.