Phypes

A Value Objects library with type validation for PHP.

Introduction

Phypes is a fully extensible value objects library with commonly used types that allows for user input validation and data storage.

Phypes has 3 components:

• Types
• Validators
• Rules

A type is an immutable object created from user input and passed on to the services in the business layer to store/manipulate/use the data.

A validator checks the input of each type and throws an InvalidArgumentException upon validation failure along with the error message and code describing the error.

A validator is further assisted using "Rules". Rules are helper classes which do validation at an atomic level. Raw data with very simple specifications are processed and validated, for example: You might want to check if the length of a supplied string is more than your limit. A combination of rules define a validator.

A standard set of data types with validators have been provided in the library. For custom validation, user-defined validators can easily be supplied as an argument to the Type.

Installation

The recommended way to install Phypes is through composer:

composer require twodee/phypes

To get the latest version from github:

git clone git://github.com/2DSharp/phypes.git

Usage

Create entity classes requiring the types as dependencies:

User.php

class User
{
  private $email;
  private $password;
  
  public function __construct(Email $email, Password $password) {
    $this->email = $email;
    $this->password = $password;
  }
  
  public function getEmail() {
    return $this->email;
  }
  
  public function getPassword() {
    //hash at this point maybe?
    return $this->password;
  }
}

Retrieve the data from the browser and store it in their correct types:

SignUpController.php

try {
  // Get the user data
  $email = new Email($_POST['email']);
  $pass = new Password($_POST['password']);
  
  // Create a new user account based on the data
  $user = new User($email, $password);
  
  // Update the user database
  $userMapper = new UserMapper();
  $userMapper->register($user);

} catch(\InvalidArgumentException $e) {
  $this->displayError($e->getMessage());
}

If you do not like our validator implementations, you don't have to use them! You can plug in your own validators with custom rules, and Phypes will do the rest for you.

With that said, you need to be extra careful to not inject an irrelevant validator to a type. A password validator to an email type would never make sense. It would in fact change the entire meaning of the email type.

As a rule of thumb, use the bundled types and validators as long as you don't really need to make a custom validator for a given type.

To inject a custom validator, implement the Validator interface:

CustomPasswordValidator.php

<?php
declare(strict_types=1);

namespace Sample\Foo;

use Phypes\Validator\Validator;
use Phypes\Error\TypeError;
use Phypes\Error\TypeErrorCode;
use Phypes\Rule\String\MinimumLength;
use Phypes\Result;

class CustomPasswordValidator implements Validator
{
    private function isLongEnough(string $password) : bool
    {
        return (new MinimumLength(8))->validate($password)->isValid();
    }
    public function validate($password, $options = []): Result\Result
    {
        if (!$this->isLongEnough($password)) {
            $error = new TypeError(TypeErrorCode::PASSWORD_TOO_SMALL,
                'The password is not at least 8 characters long');

            return new Result\Failure($error);
        }
        
        return new Result\Success();
    }
  }

A validator and a rule always return a Result after validation. You can find out if it has been successful or not using Result::isValid().

If the validation failed, you can grab the errors using Result::getErrors() or Result::getFirstError().

And then simply switch in the custom validator in the type.

$pass = new Password($_POST['password'], new CustomPasswordValidator());

That's it. The password will be verified based on your validation rules.

Any new types can be created by simply implementing the Type interface and adding a validator. A set of standard validators have already been provided with the library which will suffice for a lot of use cases.

A list of error standard codes can be found in the TypeErrorCode and RuleErrorCode abstract classes. They can be used to determine the kind of errors returned during the validation and the application can spit out custom validation errors without having to rely on the generic error messages defined in the library.