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 favour of the new auto-discovery mechanism introduced in TYPO3 v14.2 (see Feature-109412).

The mechanism was the only way to register form YAML files before TYPO3 v14.2. It required separate registrations for frontend and backend via 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 are still 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 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 the TypoScript registration with the auto-discovery directory convention introduced in TYPO3 v14.2 (see Feature-109412).

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

2. Add a config.yaml with a unique name and optionally a priority (default: 100; the core base set uses 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 the TypoScript registrations from setup.typoscript. No PHP or TypoScript registration is needed at all.

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