A book about Extbase and Fluid

Jochen Rau — Tue, 06 Jul 2010 16:22:38 +0000

Writing a book is a huge project. I never believed those people saying “Just double the time of your first estimate”. Now, after the book is finally available I would say they are wrong. You have to increase it threefold.

The book about Extbase and Fluid was written in close collaboration with Sebastian Kurfürst (core developer of Fluid) and Inken Kiupel (reader). We hope that it encourages the developers of TYPO3 extensions to get in touch with the fascinating concepts of FLOW3. And we hope that the book eases the migration to TYPO3 v5 (that’s what Extbase is all about).

We are aware of the fact that many of the English speaking TYPO3 developers are eagerly waiting for more Books about Extbase and Fluid published in English. Sebastian Kurfürst and I are currently investigating the best way to to get the book translated into English to be published on typo3.org.

If you have any questions regarding the book, or found some typos (at least 3), feel free to use the comments facility (if it is positive ;-) ) or write me an e-mail. I am really looking forward to hear from you.

You might want to support our work by ordering the book through this link.

How to Effectively use the Repository and Query Object of Extbase?

Jochen Rau — Wed, 27 Jan 2010 17:13:32 +0000

Extbase supports very well the idea of Domain-Driven Design. It supplies a Repository class to comfortably fetch your objects from. Some handy methods are already implemented. Let’s have a look at some example code.

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$blog = new Tx_BlogExample_Domain_Model_Blog('TYPO3 Development');
$blog->setDescription('A blog for professional TYPO3 developers.');

$administrator = new Tx_BlogExample_Domain_Model_Administrator();
$administrator->setName('Jochen Rau');
$administrator->setEmail('jochen.rau@example.com');
$blog->setAdministrator($administrator);

$post = new Tx_BlogExample_Domain_Model_Post('Effectively use the Query Object of Extbase');
$post->setContent('Extbase is a framework to develop ... hey, we\'re getting recursive now!');

$comment = new Tx_BlogExample_Domain_Model_Comment;
$comment->setDate(new DateTime);
$comment->setAuthor('Peter Pan');
$comment->setEmail('peter.pan@example.com');
$comment->setContent('Do you need some pills?.');
$post->addComment($comment);

$blog->addPost($post);

$blogRepository = t3lib_div::makeInstance('Tx_BlogExample_Domain_Repository_BlogRepository')
$blogRepository->add($blog);

In a first step, we create a new blog with an administrator, and a post with a comment. We instanciate the BlogRepository in line 21 and add the blog to it. That’s all we have to do. The blog is now persisted and can be fetched later from the repository again. We don’t have to say save($blog) at any time. The repository “takes care” of the blog.

Keep in mind that you have to instanciate the repository with t3lib_div::makeInstance() as it is a Singleton. If you instanciate it with new the Repository will be always an empty one if Extbase searches for objects to be persisted.

The BlogRepository class is as simple as this:

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class Tx_BlogExample_Domain_Repository_BlogRepository
extends Tx_Extbase_Persistence_Repository {
}

Most of the methods needed are already implemented in the Tx_Extbase_Persistence_Repository. These are:

$repository->add($object)
$repository->remove($object)
$repository->replace($existingObject, $newObject)
$repository->update($modifiedObject)
$repository->findAll()
$repository->countAll() // Since Extbase 1.1
$repository->removeAll()
$repository->createQuery()
$repository->countByProperty($value) // Since Extbase 1.1
$repository->findByProperty($value)
$repository->findOneByProperty($value)

The methods add() and remove() are self-explanatory. replace() takes an untracked object and puts it at the “place” of an existing one where update() just takes an existing object and updates it with the property values of the modified object.

The findByProperty() and findOneByProperty() methods are magic methods where you can replace “Property” with the name of a property of the Blog object. For example we can write $blogRepository->findByTitle('My Blog') to fetch all Blogs with the given title. This also works for objects like in $blogRepository->findByAdministrator($administrator) but not yet for properties holding aggregates. Thus, $blogRepository->findByPost($post) won’t work by now. findOneByProperty() is pretty similar to findByProperty() but returns the only first Object found.

The countAll() and countByProperty() methods are similar to the according find methods. But the don’t build objects. They only count resulting objects.

All these methods keep the underlying storage solution (mostly a relational database) transparent to the user. But what if we have special constraints that are not covered with the methods above? Let’s say we want to find the five most recent posts of a given blog. Then we can use a Query object. Let’s ask the PostRepository for those posts:

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class Tx_BlogExample_Domain_Repository_PostRepository
extends Tx_Extbase_Persistence_Repository {

public function findRecentByBlog(Tx_BlogExample_Domain_Model_Blog $blog, $limit = 5) {
$query = $this->createQuery();
$query->matching($query->equals('blog', $blog));
$query->setOrderings(array('date' => Tx_Extbase_Persistence_QueryInterface::ORDER_DESCENDING));
$query->setLimit((integer)$limit);
$posts = $query->execute();
return $posts;
}
}

The method createQuery() returns an appropriate Query object suitable for Post objects. In Line 6 we define the constraint the posts should match: $query->matching([constraint]). The constraint is returned by $query->equals('blog', $blog). There are some more methods returning a constraint:

$query->logicalAnd($constraint1, $constraint2);
$query->logicalOr($constraint1, $constraint2);
$query->logicalNot($constraint);
$query->withUid($uid);
$query->equals($propertyName, $operand, $caseSensitive = TRUE);
$query->in($propertyName, $operand); // Since Extbase 1.1
$query->contains($propertyName, $operand); // Since Extbase 1.1
$query->like($propertyName, $operand);
$query->lessThan($propertyName, $operand);
$query->lessThanOrEqual($propertyName, $operand);
$query->greaterThan($propertyName, $operand);
$query->greaterThanOrEqual($propertyName, $operand);

We can define the orderings with $query->setOrderings([orderings]) where [orderings] is expected to be an array of property-order pairs. There are two constants defining the order:

Order ascending: Tx_Extbase_Persistence_QueryInterface::ORDER_ASCENDING
Order descending: Tx_Extbase_Persistence_QueryInterface::ORDER_DESCENDING

We limit the result set to a maximum of five posts with $query->setLimit((integer)$limit). And finally invoke $query->execute() which returns us the already build posts with all their comments inside (if we are not “lazy” ;-) ). There is also a method $query->count() which does not fetch the resulting posts but counts them. Note that the Query object enables chaining. Thus, the following code does the same as the given above:

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public function findRecentByBlog(Tx_BlogExample_Domain_Model_Blog $blog, $limit = 5) {
$query = $this->createQuery();
return $query->matching($query->equals('blog', $blog))
->setOrderings(array('date' => Tx_Extbase_Persistence_QueryInterface::ORDER_DESCENDING))
->setLimit((integer)$limit)
->execute();
}

That’s it for today. I hope you got a deeper insight and I am looking forward to your comments. Maybe you want to join the discussion on the related mailing list. I have taken most of the code from the extension BlogExample which is available in the Extension Repository (TER).

What I read about development

Jochen Rau — Mon, 23 Feb 2009 15:07:01 +0000

Here are some of the books I’m reading (again and again). They were really eye-openers to me.

	Domain-Driven Design Eric Evans. Addison-Wesley Professional 2003, Hardcover, 560 pages, $47.48
	Applying Domain-Driven Design and Patterns Jimmy Nilsson. Addison-Wesley Professional 2006, Hardcover, 576 pages, $39.55
	xUnit Test Patterns Gerard Meszaros. Addison-Wesley 2007, Hardcover, 833 pages, $41.95
	Patterns of Enterprise Application Architecture (Addison-Wesley Signature Series) Martin Fowler. Addison-Wesley Professional 2002, Hardcover, 560 pages, $44.03
	Refactoring Martin Fowler. Addison-Wesley Professional 1999, Hardcover, 464 pages, $38.00

TYPO3Development » Tips and Tricks

A book about Extbase and Fluid

How to Effectively use the Repository and Query Object of Extbase?

What I read about development