Bitrix Framework

All entity objects are descendants of class Bitrix\Main\ORM\Objectify\EntityObject, with each entity having its own class for objects. By default, such class is created automatically. When you have generated ORM class annotation, with IDE highlighting this moment:

As seen above, EO_Book object class is located in the same namespace as the Table class, with the same name, but with instead of suffix Table has the prefix EO_ (abbreviated EntityObject). Such prefix is added for backward compatibility: existing projects already can have the class Book or structure

use Some\Another\Book;

resulting in conflict of repeated use of Book word. We deemed the prefix EO_ as sufficiently unique. Particularly, when in a standard case use of _ character contradicts to code naming standards: no conflicts should be present with manually described classes.

At the same time, we have allowed to conveniently customize your own, suitable class name and even place such class in another namespace, if required:

//File bitrix/modules/main/lib/test/typography/book.php

namespace Bitrix\Main\Test\Typography;

class Book extends EO_Book
{
}

Key moment - inheriting from object's base virtual class EO_Book.

Entity must be notified about a new class as follows:

//File bitrix/modules/main/lib/test/typography/booktable.php

namespace Bitrix\Main\Test\Typography;

class BookTable extends Bitrix\Main\ORM\Data\DataManager
{
	public static function getObjectClass()
	{
		return Book::class;
	}
	//...
}

Now, the method fetchObject will return objects of class Bitrix\Main\Test\Typography\Book. And after re-generating annotations, the new class start showing IDE:

Please be advised: defining your own custom classes is recommended only when you need to directly use the class name or for expanding the class with your extra features. It's not recommended to use names for standard classes in your code, for example instanceof EO_Book, new EO_Book or EO_Book::class. In such cases, it's preferable to describe your class with more "authentic" name that corresponds to naming standards, or to use impersonal methods BookTable::getObjectClass(), BookTable::createObject(), BookTable::wakeUpObject() and etc.

You may not only add your own functionality in your class, but also re-define standard named methods. It's not recommended to use descriptions for class properties with such names as primary, entity and dataClass because such names have been already used by the base class.