TYPO3 uses PHP namespaces for all classes in the Core.
The general structure of namespaces is the following:
For the Core, the vendor name is
TYPO3\CMS and the package name corresponds
to a system extension.
All classes must be located inside the
Classes folder at the root of the
(system) extension. The category name may contain several segments that correspond
to the path inside the
Finally the class name is the same as the corresponding file name, without the
"UpperCamelCase" is used for all segments.
The good old
t3lib_div class has been renamed to:
This means that the class is now found in the
core system extension, in folder
Classes/Utility, in a file named
Usage in extensions¶
Extension developers are free to use their own vendor name. Important: It may consist of one segment only. Vendor names must start with an uppercase character and are usually written in UpperCamelCase style. In order to avoid problems with different filesystems, only the characters a-z, A-Z, 0-9 and the dash sign "-" are allowed for package names – don't use special characters:
// correct vendor name for 'web company': \WebCompany // wrong vendor name for 'web company': \Web\Company
The vendor name
TYPO3\CMS is reserved and may not be used by extensions!
The package name corresponds to the extension key. Underscores in the extension key are removed in the namespace and replaced by upper camel-case. So extension key:
in the namespace.
As mentioned above, all classes must be located in the
Classes folder inside
your extension. All sub-folders translate to a segment of the category name and the class
name is the file name without the
Looking at the "examples" extension, file
corresponds to the class with
as fully qualified name.
Inside the class, the namespace is declared as:
<?php namespace Documentation\Examples\Controller;
Namespaces in Extbase¶
When registering components in Extbase, the "UpperCamelCase" notation of the extension key is used.
For a backend module:
use TYPO3\CMS\Extbase\Utility\ExtensionUtility; ExtensionUtility::registerModule( '<ExtensionName>', // ... );
For a frontend module:
use TYPO3\CMS\Extbase\Utility\ExtensionUtility; ExtensionUtility::configurePlugin( '<ExtensionName>', // ... );
Namespaces for test classes¶
As for ordinary classes, namespaces for test classes start with a vendor name followed by the extension key.
All test classes reside in a
Tests folder and thus the third segment
of the namespace must be "Tests". Unit tests are located in a
which is the fourth segment of the namespace. Any further subfolders will
be subsequent segments.
So a test class in
EXT:foo_bar_baz/Tests/Unit/Bla/ will have as namespace
The following example shows how you can create instances by means of
use TYPO3\CMS\Core\Utility\GeneralUtility; use TYPO3\CMS\Frontend\ContentObject\ContentObjectRenderer; $contentObject = GeneralUtility::makeInstance(ContentObjectRenderer::class);
There is no need for
include() statements. All
classes adhering to namespace conventions will automatically be located and
included by the autoloader.
For more information about PHP namespaces in general, you may want to refer to the PHP documentation and in particular the Namespaces FAQ.