Feature: #96005 - Allow tagging and aliasing of data processors

See forge#96005

Description

It is now possible to set an alias / identifier for data processors by tagging them with the data.processor tag in the Configuration/Services.yaml file and defining the identifier key. On the one hand, this improves readability in corresponding TypoScript configurations, since those aliases / identifiers can be used instead of the fully-qualified class name, while also providing dependency injection out of the box. On the other hand, this allows improving and enhancing the functionality of data processors in the future by automatically adding tagged processors to a registry.

Tagging a data processor in the Configuration/Services.yaml file:

Vendor\MyExt\DataProcessing\AwesomeProcessor:
  tags:
    - { name: 'data.processor', identifier: 'awesome' }

Usage in TypoScript:

dataProcessing.10 = awesome

All data processors shipped by TYPO3 are already tagged and can therefore be used with their alias / identifier in your TypoScript configuration:

# Default with fully-qualified class name (still supported):
dataProcessing {
    10 = TYPO3\CMS\Frontend\DataProcessing\CommaSeparatedValueProcessor
    20 = TYPO3\CMS\Frontend\DataProcessing\DatabaseQueryProcessor
    30 = TYPO3\CMS\Frontend\DataProcessing\FilesProcessor
    40 = TYPO3\CMS\Frontend\DataProcessing\FlexFormProcessor
    50 = TYPO3\CMS\Frontend\DataProcessing\GalleryProcessor
    60 = TYPO3\CMS\Frontend\DataProcessing\LanguageMenuProcessor
    70 = TYPO3\CMS\Frontend\DataProcessing\MenuProcessor
    80 = TYPO3\CMS\Frontend\DataProcessing\SiteProcessor
    90 = TYPO3\CMS\Frontend\DataProcessing\SiteLanguageProcessor
    100 = TYPO3\CMS\Frontend\DataProcessing\SplitProcessor
}

# New alternative using the alias / identifier:
dataProcessing {
    10 = comma-separated-value
    20 = database-query
    30 = files
    40 = flex-form
    50 = gallery
    60 = language-menu
    70 = menu
    80 = site
    90 = site-language
    100 = split
}

Note

The standard service aliasing mechanism is still supported. However, it is recommended to tag the data processors instead, because this will automatically add them to the internal DataProcessorRegistry, enabling dependency injection by default. Otherwise the service would need to be set public.

Impact

Data processors can now be tagged with the data.processor tag. This allows to define an alias / identifier, which can then be used instead of the fully-qualified class name, e.g. in TypoScript configurations.