Simple Model - Mapper abstract pair for PHP

Cat.php

<?php

namespace Sandfox\Model;

use \Sandfox\Model\ModelAbstract;

class Cat extends ModelAbstract
{
	/**
	 * Define data names and defaults here
	 * @var array
	 */
	protected $data = array(
			'id' => null,
			'food' => null,
		);

}

CatMapper.php

<?php

namespace Sandfox\Mapper;

use \Sandfox\Model\Cat as CatModel;
use \Sandfox\Mapper\MapperAbstract;
use \Sandfox\Model\ModelAbstract;


class Cat extends MapperAbstract
{
	protected $modelClass = '\Sandfox\Model\Cat';
	protected $tableName = 'cats';

	protected function hydrate(\Zend_Db_Table_Row $row)
	{
		$cat = new $this->modelClass;

		$cat->food = $row->food;
		$cat->id = $row->cat_id;

		return $subscriber;
	}

	protected function dehydrate(ModelAbstract $model)
	{
		$data = array();
		$data['food'] = $model->food;
		$data['cat_id'] = $model->id;


		return $data;
	}
}

MapperAbstract.php

<?php

namespace Sandfox\Mapper;

use \Sandfox\Model\ModelAbstract;

/**
 * Abstract class to handle the generics of our mappers
 * FIXME (everything)
 */
abstract class MapperAbstract
{
	protected $modelClass = '\Sandfox\Model\ModelAbstract';

	protected $tableGateway = null;

	protected $tableName = null;

	protected $identityMap = array();



	public function __construct(\Zend_Db_Table_Abstract $tableGateway = null)
	{
		if($tableGateway === null) {
			$this->tableGateway = new \Zend_Db_Table($this->tableName);
		} else {
			$this->tableGateway = $tableGateway;
		}

	}

	protected function getGateway()
	{
		return $this->tableGateway;
	}



	public function getById($id)
	{
		if ($this->hasIdentity($id)) {
			return $this->getIdentity($id);
		}

		$record = $this->getGateway()->find($id)->current();
		$model = $this->hydrate($record);
		$this->setIdentity($model->id, $model);
		return $model;

	}

	protected function getIdentity($id)
	{
		if ($this->hasIdentity($id)) {
			return $this->identityMap[$id];
		}

	}

	protected function setIdentity($id, $model)
	{
		$this->identityMap[$id] = $model;
	}

	protected function hasIdentity($id)
	{
		return array_key_exists($id, $this->identityMap);
	}

	/**
	 * Hydrates the object model with the data from the persistence layer
	 * @param  array $data [description]
	 * @return \Marlow\Model\ModelAbstract      [description]
	 */
	abstract protected function hydrate(\Zend_Db_Table_Row $row);

	/**
	 * Turns the model into a simple array/whatever to be fed in persistence layer
	 * @param  ModelAbstract $model [description]
	 * @return [type]               [description]
	 */
	abstract protected function dehydrate(ModelAbstract $model);

	public function save(ModelAbstract $model)
	{
		$data = $this->dehydrate($model);

		if (!isset($model->id)) {
			$model->id = $this->getGateway()->insert($data);
			$this->setIdentity($model->id, $model);
			return $model->id;
		} else {
			$where = $this->getGateway()->getAdapter()->quoteInto('id = ?', $author->id);
			return $this->getGateway()->insert($data, $where);
		}
	}

	public function delete(ModelAbstract $model)
	{
		$where = $this->getGateway()->getAdapter()->quoteInto('id = ?', $entry->id);
		$this->getGateway()->delete($where);
	}

	public function update(ModelAbstract $model)
	{

	}
	
}

ModelAbstract.php

<?php

namespace Sandfox\Model

abstract class ModelAbstract
{
	protected $data = array();

	public function construct(array $data = null)
	{
		foreach ($data as $name => $value) {
			//Do I need the  curly braces?
			$this->{$name} = $value;
		}

	}

	public function toArray()
	{
		return $this->data;
	}

	public function __set($name, $value)
	{
		if (!array_key_exists($name, $this->data)) {
			throw new \Exception("Attempting to set dynamically set non-existent property $name");
		}

		$this->data[$name] = $value;
	}

	public function __get($name)
	{
		if (array_key_exists($name, $this->data)) {
			return $this->data[$name];
		}
	}

	public function __isset($name)
	{
		return isset($this->data[$name]);
	}

	public function __unset($name)
	{
		if (isset($this->data[$name])) {
			unset($this->data[$name]);
		}
	}
}