Problem on https://docs.typo3.org/m/typo3/reference-coreapi/13.4/en-us//ExtensionArchitecture/Extbase/Reference/Domain/Model/Relations/Index.html

[killerwhale9]

Current behavior

The “m:n relationship” section of the Extbase Relations documentation contains a code snippet that does not reflect an m:n relationship.

It currently shows:

protected ?Person $author = null;
protected ?Person $secondAuthor = null;

This actually illustrates an n:1 relation (a post has one author), not an m:n relation between Post and Category as described in the preceding text.

This can lead to confusion for readers trying to understand how to implement m:n relations in Extbase.

Expected behavior/output

The example for an m:n relationship should:

Show a Post model containing an ObjectStorage<Category> $categories property.

Optionally show the inverse relation in the Category model.

Reflect a real many-to-many relation consistent with the description above the code snippet.

Possibly reference the required TCA configuration with MM table.

Links

Documentation page: https://docs.typo3.org/m/typo3/reference-coreapi/13.4/en-us/ExtensionArchitecture/Extbase/Reference/Domain/Model/Relations/Index.html

Section: m:n relationship (Blog post ↔ Category example)

TYPO3 versions

13.4 (may affect other versions too)

Possible Solution

Replace the current author code snippet with a proper m:n example, e.g.:

/**
 * @var \TYPO3\CMS\Extbase\Persistence\ObjectStorage<\Vendor\Extension\Domain\Model\Category>
 * @TYPO3\CMS\Extbase\Annotation\ORM\Lazy
 */
protected ObjectStorage $categories;

Add a short TCA example with MM table configuration for clarity.

Additional context

This part of the documentation is frequently referenced by developers learning Extbase relations. Having a correct m:n code sample will avoid misunderstandings between n:1 and m:n relations and improve the learning curve for TYPO3 developers.