public function testEmailDecoratorGetsTheLogMessage()
{
$message = 'this text should be logged';
$log = new Example\Logger($message);
$emailLogger = new Example\EmailLogger($log);
$this->assertEquals($message, $emailLogger->getMessage());
}
<?php
require 'logger.php';
use DesignPatterns\Decorator\Example\Logger as Example;
// This is how it was usually done, you know..
$log = new Example\Logger('User just logged in');
// However, we just realized that we need to log message in a special way..
// But we don't want to modify Logger class, so let's initialize Decorator
// that knows to do the stuff we want like we want
$emailLogger = new Example\EmailLogger($log);
// ..and now we can use $emailLogger just like we used $log before
// but the result will be different
$emailLogger->log();
echo 'Following message was sent by email: ' . $emailLogger->getMessage();
