Namespaces
TYPO3 uses PHP namespaces for all classes in the Core.
The general structure of namespaces is the following:
\{VendorName}\{PackageName}\({CategoryName}\)*{ClassName}
For the Core, the vendor name is \TYPO3\
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 Classes
folder.
Finally the class name is the same as the corresponding file name, without the
.php
extension.
"UpperCamelCase" is used for all segments.
Core example
The good old t3lib_
class has been renamed to:
\TYPO3\
This means that the class is now found in the core
system extension, in folder
Classes/
, in a file named General
.
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
Attention
The vendor name TYPO3\
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:
weird-name_examples
would become:
Weird-nameExamples
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 .php
extension.
Looking at the "examples" extension, file
examples/
corresponds to the class with \Documentation\
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:
For a frontend module:
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 Unit
folder
which is the fourth segment of the namespace. Any further subfolders will
be subsequent segments.
So a test class in EXT:
will have as namespace
\My
.
Creating Instances
The following example shows how you can create instances by means of
General
:
use TYPO3\CMS\Core\Utility\GeneralUtility;
use TYPO3\CMS\Frontend\ContentObject\ContentObjectRenderer;
$contentObject = GeneralUtility::makeInstance(ContentObjectRenderer::class);
include
and required
There is no need for require
or include
statements. All
classes adhering to namespace conventions will automatically be located and
included by the autoloader.
References
For more information about PHP namespaces in general, you may want to refer to the PHP documentation and in particular the Namespaces FAQ.