Introduction

This Documentation was written for version 7.0.x of the extension.

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.

  1. Base class file

    ../_images/base.png

  2. Extend class file

    ../_images/extend.png

  3. Merged result file

    ../_images/merged.png

Explanation

  1. Namespace

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

  2. 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;

  3. Class

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

  4. Implements

    Implements are used uniquely from the base and extend file

  5. Traits

    All traits from base and extend file are taken uniquely.

  6. Properties

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

  7. 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.

  8. Methods

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

  9. 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