A simple class based file (semi-auto-)loader that needs a path, relative to the plugins root directory as input argument.

Example.php

<?php

$fileLoader = new FileLoader( 'assets/php' );

foreach ( $fileLoader as $file )
	$fileLoader->loadFile( $file );

WordPressFileLoader.php

<?php

namespace SomeNamespace;

defined( 'ABSPATH' ) OR exit;

class FileLoader implements \IteratorAggregate
{
	private $path = '';

	private $files = array();

	public function __construct( $path )
	{
		$this->setPath( $path );
		$this->setFiles();
	}

	public function setPath( $path )
	{
		empty( $this->path )
			AND $this->path = trailingslashit( plugin_dir_path( __FILE__ ).$path );
	}

	public function setFiles()
	{
		return $this->files = glob( "{$this->getPath()}*.php" );
	}

	public function getPath()
	{
		return $this->path;
	}

	public function getIterator()
	{
		$iterator = new \ArrayIterator( $this->files );
		return $iterator;
	}

	public function loadFile( $file )
	{
		include_once $file;
	}
}