PHPCR: Reading and writing

This post is the second in a serie about PHPCR with Jackalope. If you want to know more about PHPCR, I recommend watching the slides about PHPCR.

In the previous post, I talked about setting up your repository. In this post we will start playing with some actual content.

Insert data

To show the basic usage of PHPCR, we are going to load some data into our repository. For this I used Faker.

$ composer require fzaninotto/faker ~1.2

Because we are going to add more CLI scripts later on, I created a simple Symfony Console Application for this. I called it console at placed it in the root. You can find the console and the Command on Github.

With PHPCR, it is pretty easy to create new nodes. You simply call addNode on it's parent node. So before we can create new nodes, we need to rootNode. You can request the rootNode from the PHPCR session.

$session = $this->getHelper('phpcr')->getSession();

Here we use the helper that we defined in cli-config.php in my previous post to get the Session. Now we have the session, we can simply retrieve the rootNode with $session->getRootNode(); With the rootNode, we can start creating fake nodes.

$faker = \Faker\Factory::create();
while (count($rootNode->getNodes()) < 10) {

    try {
        $node = $rootNode->addNode($faker->word);

        $node->setProperty('title', $faker->name);
        $node->setProperty('body', $faker->text(1000));
    } catch (\PHPCR\ItemExistsException $e) {
        // Ignore, and try again
    }
}

$session->save();

On line 5, you see the addNode, the first argument you give it, is the nodeName. You can give a second argument, to define the nodeType but in this case we will use the default value (which will be nt:unstructured). On line 7 and 8, we set 2 properties with random values. The first argument is the name of the property, the second is the value. You can also give a third parameter, to indicate the type, but this is not required as PHPCR will guess the type based on given value.

Because nodeNames need to be unique, Jackalope will throw a ItemExists Exception when we try to create 2 nodes with the same name. As that might happen with random date, we just catch the exception and try again.

Reading the data

Now we have some fake data, we can try to query it again. We start with simply iterating over all the childNodes. Because every Node implements Traversable, we can simply loop over a node to get its children.

foreach ($rootNode as $childNode) {
    $name = $childNode->getName();
    $title = $body = null;
    if ($childNode->hasProperty('title')) {
        $title = $childNode->getProperty('title')->getValue();
    }
    if ($childNode->hasProperty('body')) {
        $body = $childNode->getProperty('body')->getValue();
    }
    // .. do something
}

All pretty straight forward. To retrieve propertyValues, there are a few alternatives. You can, for example, use some of other property methods, to convert the property value to another type.

$dummyNode->setProperty('floatProperty', 3.1415);
$property = $dummyNode->getProperty('floatProperty');
var_dump($property->getString()); // string(6) "3.1415"
var_dump($property->getLong()); // int(3)
var_dump($property->getBoolean()); // bool(true)
var_dump($property->getBinary()); // resource(#) of type (stream)

Besides that, you can use $node->getPropertyValue('propertyName'). By passing the second argument, you can convert the value to the desired type.

$dummyNode->getPropertyValue('floatProperty', \PHPCR\PropertyType::STRING); // string(6) "3.1415"

Finding nodes

You can also retrieve a node by it's path or multiple nodes by an array with paths

$dummyNode = $session->getNode('/dummy');
$nodes = $session->getNodes(array('/', '/dummy'));

Or retrieve a childNode by it's name:

$dummyNode = $rootNode->getNode('dummy');
// Note that we call this on $rootNode, not on $session

You can even find nodes by searching with wildcards:

$rootNode->getNodes('c*');

There is a lot more to learn about nodes and properties. In the following chapters some of those features will be explained. If you want to learn more about the possibilities, you might want to look at the PHPCR api tests.

In the next post, we will play with Queries and the QueryObjectModel.