Collecting Data from Atlas ORM with PHP Debug Bar

In my last article, I talked about how I found an N+1 bug in Atlas ORM.

I had mentioned how it took a little work to get PHP Debug Bar configured with Atlas but didn't really explain why it was difficult, or how I got them working together.

At first, it seemed like it would be easy. Debug Bar comes with a PDOCollector and Atlas is based on PDO. In Atlas\Orm\AtlasContainer it creates a new Aura\Sql\ConnectionLocator then creates and adds an Aura\Sql\ExtendedPdo connection to it.

PHP Debug Bar requires you wrap your PDO connection in DebugBar\DataCollector\PDO\TraceablePDO which extends PDO.

Aura\Sql\ExtendedPdo wraps a PDO connection and extends PDO however DebugBar\DataCollector\PDO\TraceablePDO is not a Aura\Sql\ExtendedPdo object.

That means that I need to wrap PDO in DebugBar\DataCollector\PDO\TraceablePDO which is then wrapped in Aura\Sql\ExtendedPdo.

There is no easy way of doing that without replacing some code.

The first step is to create a new ExtendedPdo class that extends Aura\Sql\ExtendedPdo that overrides connect() which instantiates the PDO connection. We want to wrap the newly created connection in DebugBar\DataCollector\PDO\TraceablePDO.

Next, we create a new AtlasContainer class that extends Atlas\Orm\AtlasContainer that overrides setConnectionLocator to instantiates my new ExtendedPdo instead of Aura\Sql\ExtendedPdo.

Finally, we can use the DebugBar\DataCollector\PDO\PDOCollector which requires a DebugBar\DataCollector\PDO\TraceablePDO connection. We can get that out of our AtlasContainer like this:

$pdo = $atlasContainer->getConnectionLocator()->getDefault()->getPdo();

To make this step easier I created AtlasOrmCollector which extends DebugBar\DataCollector\PDO\PDOCollector but expects my AtlasContainer instead of a PDO connection in the constructor. This way I can pull out the DebugBar\DataCollector\PDO\TraceablePDO connection and pass it to the parent constructor.

I've packaged all of this up into the library AtlasOrm.DebugBar.Bridge which is also available on packagist as cadre/atlasorm-debugbar-bridge.

You can now integrate PHP Debug Bar into your applications that use Atlas ORM as simply as this:

$atlasContainer = new Cadre\AtlasOrmDebugBarBridge\AtlasContainer(
    'mysql:host=localhost;dbname=testdb',
    'username',
    'password'
);

$debugbar = new DebugBar\StandardDebugBar();
$debugbar->addCollector(
    new Cadre\AtlasOrmDebugBarBridge\AtlasOrmCollector($atlasContainer)
);