How to use \Zend\Cache andZend\Db\RowGateway\RowGateway together? - zend-framework2

Question

I have an abstract table class with code similar to this:
function fetchById($id) {
$id = (int) $id;
$cacheName = sprintf('%s-%s', stripslashes(get_class($this)), hash('sha256', sprintf(
'%s-%s-%s', get_class($this), __FUNCTION__, $id
)));
if (($row = $this->cache->getItem($cacheName)) == FALSE) {
$rowset = $this->tableGateway->select(array('id' => $id));
$row = $rowset->current();
if (!$row) {
throw new \Exception("Could not find row $id");
}
$this->cache->setItem($cacheName, $row);
}
return $row;
}
This works well enough for the default ArrayObject that $row is returned as, however I am now wanting to include additional functionality into my row objects (so that the functionality is not included in multiple, unrelated, places such as different controllers, etc).
To this end I have created an ArrayObjectPrototype extending Zend\Db\RowGateway\RowGateway, however when I try to cache the row I am getting the following error message: You cannot serialize or unserialize PDO instances
Oh dear.
I have no problem adding __wake and __sleep functions to my row object, but how do I get the PDO object into my __wake function?
I am creating my cache in my application.config.php file:
'ZendCacheStorageFactory' => function() {
return \Zend\Cache\StorageFactory::factory(
array(
'adapter' => array(
'name' => 'filesystem',
'options' => array(
'dirLevel' => 2,
'cacheDir' => 'data/cache',
'dirPermission' => 0755,
'filePermission' => 0666,
),
),
'plugins' => array('serializer'),
)
);
},
I assume I have to create a custom plugin that I pass the db adaptor into? But I am totally lost on how to do that.

Answer 1

What I have done (perhaps incorrectly) is create an abstract row class that does not save the pdo instance. This class extends the RowGateway class but overrides the __construct, initialize, save and delete functions (all the functions that require the pdo
/**
* Abstract table row class.
*
* #package RPK
* #subpackage Db
* #author SuttonSilver
*/
namespace RPK\Db;
use Zend\Db\Adapter\Adapter;
use Zend\Db\RowGateway\Exception\RuntimeException;
use Zend\Db\RowGateway\RowGateway;
use Zend\Db\Sql\Sql;
use Zend\Db\Sql\TableIdentifier;
use Zend\Db\RowGateway\Feature\FeatureSet;
abstract class RowAbstract extends RowGateway {
/**
* Constructor
*
* #param string $primaryKeyColumn
* #param string|TableIdentifier $table
* #param Adapter|Sql $adapterOrSql
* #throws Exception\InvalidArgumentException
*/
public function __construct($primaryKeyColumn, $table, $adapterOrSql = null) {
// setup primary key
$this->primaryKeyColumn = empty($primaryKeyColumn) ? null : (array) $primaryKeyColumn;
// set table
$this->table = $table;
$this->initialize();
}
/**
* initialize()
*/
public function initialize() {
if ($this->isInitialized) {
return;
}
if (!$this->featureSet instanceof FeatureSet) {
$this->featureSet = new FeatureSet;
}
$this->featureSet->setRowGateway($this);
$this->featureSet->apply('preInitialize', []);
if (!is_string($this->table) && !$this->table instanceof TableIdentifier) {
throw new RuntimeException('This row object does not have a valid table set.');
}
if ($this->primaryKeyColumn === null) {
throw new RuntimeException('This row object does not have a primary key column set.');
} elseif (is_string($this->primaryKeyColumn)) {
$this->primaryKeyColumn = (array) $this->primaryKeyColumn;
}
$this->featureSet->apply('postInitialize', []);
$this->isInitialized = true;
}
/**
* Save any changes to this row to the table
* #throws \Exception
*/
public function save() {
throw new \Exception('No PDO object available.');
}
/**
* Delete this row from the table
* #throws \Exception
*/
public function delete() {
throw new \Exception('No PDO object available.');
}
}