Extending classes 

The sole purpose of this extension is to fill a gap that extbase leaves open.

As it is not possible to extend classes in extbase directly its sometimes not possible to add properties and methods to a class. This is valid for all cases where the class is given as an type hint to an action.

Arguments of an action are mapped from the request to the concrete class by the argument mapper. The argument mapper does not take TypoScript object className mapping into account as the property mapper. Due to this its not possible to just extend the class and have the extends available.

To cope with this and be able to add custom properties to a class the extender registers a custom spl class loader. This kicks in for every configured class and required a compiled class from the class cache.

The class cache gets generated on every hit where an configured compilation is not available and after every clear system cache. In both cases the class cache manager rebuilds the complete class cache.

As the class cache is registered to the system cache group it gets cleared on every clear system cache or clear all caches. After that a hook gets called that rebuilds the class cache. Unless a huge amount of extends are configured there should be a prefilled class cache on every request.

Deep dive into an example 

The cache manager parses the base and extend files to gather the colored parts of the following images, generates a combined file as shown in the merged result and adds it to the cache.

• Base class file

  

• Extend class file

  

• Merged result file

  

Explanation 

• Namespace

  The Namespace is taken from the base file. The namespace of the extended file is ignored.

• Uses

  All uses from base and extending file are taken uniquely. If an use appears with diverting as alias it is present twice in the merged file.

  example of uses appearing twice

  use Psr\Log\LoggerAwareTrait;
  use Psr\Log\LoggerAwareTrait as T;

  Copied!

• Class

  The class name and the extends part is taken from the base class.

• Implements

  Implements are used uniquely from the base and extend file

• Traits

  All traits from base and extend file are taken uniquely.

• Properties

  All properties from base and extend file are taken without check if they are not colliding.

• Construct

  The __construct of base and extend file are taken with merged contents and arguments. Where arguments from base take priority. All line of code in the method are taken. If the __construct of the extend file contains a parent::__construct call it gets removed.

• Methods

  All methods beside __construct from base and extend file are taken without check if they are not colliding.

• Comment

  The comment is based on the base and extending files and display which files path were taken into account.

Example source 

The base file content could be found in EXT:extender/Tests/Fixtures/Extensions/base_extension/Classes/Domain/Model/Blob.php

The extend file content is derived from EXT:extender/Tests/Fixtures/Extensions/extending_extension/Classes/Domain/Model/BlobExtend.php

Important 

namespace Fixture\ExtendingClass\Domain\Model;

class ExtendingModel extends \Fixture\BaseClass\Domain\Model\BaseModel
{
}

namespace Fixture\ExtendingClass\Domain\Model;

class BaseModel
{
}

namespace Fixture\ExtendingClass\Domain\Model;

use Fixture\BaseClass\Domain\Model\BaseModel;

class ExtendingModel extends BaseModel
{
}

namespace Fixture\BaseClass\Domain\Model;

use Fixture\BaseClass\Domain\Model\BaseModel;

class BaseModel
{
}

Require via command 

You can add extender with composer require.

composer require evoweb/extender

Modify composer.json 

Additionally evoweb/extender can be added to the require in your composer.json, like in the following example and run 'composer install'.

{
    "require": {
        ...
        "evoweb/extender": "*"
    }
}

Configure the extend of a class 

Since version 10.0.0 the registration of class extends needs to be configured in services.yaml like in this example.

services:
  Fixture\ExtendingExtension\Domain\Model\BlobExtend:
    tags:
      -
        name: 'extender.extends'
        class: Fixture\BaseExtension\Domain\Model\Blob

• FixtureBaseExtensionDomainModelBlob is the class that should be extended
• FixtureExtendingExtensionDomainModelBlobExtend is the class that extends

Change of command name 

The command was renamed from "extender:rebuild" to "extender:clearClassCache" to better reflect what the command is doing.

Change of extending configuration in 10.0.0 

$GLOBALS['TYPO3_CONF_VARS']['EXTENSIONS']['base_extension']['extender'][
    \Fixture\BaseExtension\Domain\Model\Blob::class
]['extending_extension'] = 'EXT:extending_extension/Classes/Domain/Model/BlobExtend.php';

Fixture\ExtendingExtension\Domain\Model\BlobExtend:
  tags:
    -
      name: 'extender.extends'
      class: Fixture\BaseExtension\Domain\Model\Blob

Change of extending configuration in 7.0.0 

$GLOBALS['TYPO3_CONF_VARS']['EXTCONF']['store_finder']['extender'][
    \Evoweb\StoreFinder\Domain\Model\Location::class
]['sitepackage'] = 'EXT:sitepackage/Classes/Domain/Model/Location.php';