Deprecation: #109412 - TypoScript-based form YAML registration 

Description 

The TypoScript-based registration of form YAML configuration files via plugin.tx_form.settings.yamlConfigurations and module.tx_form.settings.yamlConfigurations has been deprecated in favor of the new auto-discovery mechanism introduced in TYPO3 v14.2 (see Feature-109412).

Before TYPO3 v14.2 this was the only way to register EXT:form YAML files. It required separate registration of the frontend and the backend in TypoScript:

plugin.tx_form.settings.yamlConfigurations {
    1732785702 = EXT:my_extension/Configuration/Form/MySetup.yaml
}

# Backend had to be registered separately:
module.tx_form.settings.yamlConfigurations {
    1732785703 = EXT:my_extension/Configuration/Form/MySetup.yaml
}

The TypoScript-based paths will still be loaded during the deprecation period but will be removed in TYPO3 v15.0.

Impact 

Extensions that register form YAML files via TypoScript will trigger a PHP E_USER_DEPRECATED error. The registered YAML files are still loaded and will remain functional during the deprecation period.

Affected installations 

All installations where an extension registers form YAML files via:

• plugin.tx_form.settings.yamlConfigurations
• module.tx_form.settings.yamlConfigurations

Migration 

Replace TypoScript registration with the auto-discovery directory convention introduced in TYPO3 v14.2 (see Feature-109412).

1. Create directory EXT:my_extension/Configuration/Form/MySet/.

2. Add a config.yaml file with a unique name and, optionally, a priority value (default: 100; the core base set is priority 10):

   EXT:my_extension/Configuration/Form/MySet/config.yaml

   name: my-vendor/my-form-set
   label: 'My Custom Form Set'
   priority: 200

   Copied!

3. Add your existing form configuration to config.yaml below the metadata keys:

   EXT:my_extension/Configuration/Form/MySet/config.yaml

   name: my-vendor/my-form-set
   label: 'My Custom Form Set'
   priority: 200
   
   # Content of your former MySetup.yaml
   persistenceManager:
     allowedExtensionPaths:
       10: 'EXT:my_extension/Resources/Private/Forms/'

   Copied!
4. Remove TypoScript registrations from setup.typoscript. PHP or TypoScript registration is no longer necessary.

The YAML files are picked up automatically for both frontend and backend without any additional registration.