A aop based Unit Of Work prototype/example with minimal code

aop-uow-change-tracking.php

<?php

/**
 * Foo is an Entity
 */
class Foo
{
    protected $bar = 'original';
    
    public function getBar()
    {
        return $this->bar;
    }
    
    public function setBar($bar)
    {
        $this->bar = $bar;
    }
}

/**
 * Unit of work that requires and consumes AopJoinPoint
 *
 */
class UnitOfWork
{
    protected $data = array();

    public function register($class)
    {
        // setup aop
        aop_add_before("write $class->*", array($this, 'track'));
    }

    public function track(AopJoinPoint $p)
    {
        $obj = $p->getObject();
        $objHash = spl_object_hash($obj);
        
        if (!isset($this->data[$objHash])) {
            $this->data[$objHash] = array(
                'dirty' => array(),
                'values' => array(),
                'obj' => $obj
            );
        }
        
        $propName = $p->getPropertyName();
        
        $objRef = new ReflectionObject($obj);
        $pRef = $objRef->getProperty($propName);
        $pRef->setAccessible(true);
        $this->data[$objHash]['dirty'][$propName] = true;
        if (!isset($this->data[$objHash]['values'][$propName])) {
            $this->data[$objHash]['values'][$propName] = $pRef->getValue($obj);
        }
    }
    
    public function renderDirties()
    {
        foreach ($this->data as $hash => $objData) {
            $obj = $objData['obj'];
            echo 'For object type ' . get_class($obj) . " [hash: $hash]" . PHP_EOL;
            $refl = new ReflectionObject($obj);
            foreach ($objData['dirty'] as $prop => $isDirty) {
                $propRefl = $refl->getProperty($prop);
                $propRefl->setAccessible(true);
                echo '  "' . $prop . '" value changed: ' . $objData['values'][$prop] . ' -> ' . $propRefl->getValue($obj);
            }
        }
    }
}

$uow = new UnitOfWork;
$uow->register('Foo');

// do something with your entity
$f = new Foo;
$f->setBar('bam');

// figure out what happened in our entities state:
$uow->renderDirties();

/**
 * Output:
 *
 * For object type Foo [hash: 0000000043455f9600000000597c323d]
 *   "bar" value changed: original -> bam
 *
 */