README

A PHP library providing function handling utilities including a Chain of Responsibility pattern implementation and function execution utilities.

Installation

Install the package via Composer:

composer require vairogs/functions-handler

Requirements

PHP 8.4 or higher

Usage

The Handler package provides several utilities for handling function execution and implementing the Chain of Responsibility pattern.

Chain Class

The Chain class implements a simple pipeline pattern for function composition:

use Vairogs\Functions\Handler\Chain;

// Create a new chain with an initial value
$chain = new Chain('initial value');

// Or use the static factory method
$chain = Chain::of('initial value');

// Pipe the value through a series of transformations
$result = $chain
    ->pipe(fn($value) => strtoupper($value))
    ->pipe(fn($value) => $value . ' - transformed')
    ->get();

// $result now contains "INITIAL VALUE - transformed"

Handler Interface and AbstractHandler

The Handler interface and AbstractHandler class implement the Chain of Responsibility pattern:

use Vairogs\Functions\Handler\AbstractHandler;
use Vairogs\Functions\Handler\Handler;

// Create custom handlers by extending AbstractHandler
class CustomHandler extends AbstractHandler
{
    public function handle(...$arguments): mixed
    {
        // Process the request
        $result = $this->processRequest(...$arguments);

        // If this handler can't process the request, pass it to the next handler
        if (null === $result) {
            return parent::handle(...$arguments);
        }

        return $result;
    }

    private function processRequest(...$arguments): mixed
    {
        // Custom processing logic
        // Return null if this handler can't process the request
    }
}

// Chain handlers together
$handler1 = new CustomHandler();
$handler2 = new AnotherCustomHandler();
$handler3 = new FinalHandler();

$handler1->next($handler2);
$handler2->next($handler3);

// Process a request through the chain
$result = $handler1->handle($request);

FunctionHandler

The FunctionHandler executes a specified function as part of the chain:

use Vairogs\Functions\Handler\FunctionHandler;

// Create a handler for a global function
$handler = new FunctionHandler('strtoupper');
$result = $handler->handle('hello'); // Returns "HELLO"

// Create a handler for an object method
$object = new YourClass();
$handler = new FunctionHandler('methodName', $object);
$result = $handler->handle($arg1, $arg2); // Calls $object->methodName($arg1, $arg2)

// Chain with other handlers
$nextHandler = new AnotherHandler();
$handler->next($nextHandler);
$result = $handler->handle('hello'); // If the function returns null, passes to next handler

Features

For a complete list of all classes and methods available in this package, see Features.

License

This package is licensed under the BSD-3-Clause License.

About Vairogs

This package is part of the vairogs/vairogs project - a comprehensive PHP library and Symfony bundle that provides a collection of utilities, components, and integrations for Symfony applications.

The main project includes:

• Various utility functions and components
• Doctrine ORM tools and extensions
• API Platform integrations
• Symfony bundle for easy configuration
• And much more

If you find this Handler component useful, you might want to check out the full Vairogs project for additional tools and utilities that can enhance your Symfony application development.

To install the complete package:

composer require vairogs/vairogs