Important: #80241 - EXT:form simplify translation handling

See Issue #80241

Description

If an integrator wants to add translations for new form elements he can only define a new translation file which must contain all translation keys. This patch makes it possible to define multiple translation files.

Before this patch:

TYPO3:
  CMS:
    Form:
      prototypes:
        standard:
          formElementsDefinition:
            Form:
              renderingOptions:
                translation:
                  translationFile: 'EXT:form/Resources/Private/Language/locallang.xlf'

After this patch:

TYPO3:
  CMS:
    Form:
      prototypes:
        standard:
          formElementsDefinition:
            Form:
              renderingOptions:
                translation:
                  translationFile:
                    10: 'EXT:form/Resources/Private/Language/locallang.xlf'
                    20: 'EXT:my_ext/Resources/Private/Language/locallang.xlf'

The translation keys will be searched within the referenced files. The search order is from the key with the highest number to the lowest. If a translation key is found within one of these files the search will stop.

This makes it possible to only define new keys within the custom translations and use the default form translations as well. The default settings keep the translationFile property as string because of backward compatibility.

Before this patch the "BaseFormElementMixin" inherits the "translationSettingsMixin". Thus, the "renderingOptions.translation..." are copied to each form element. This is inconvenient if an integrator defines his own prototype which inherits from the standard prototype because he must redefine the "renderingOptions.translation..." options for each form element.

Since there already is a fallback strategy to the "renderingOptions.translation..." options from the root form element - if this option is not set within the child form elements - we can simply apply the "translationSettingsMixin" to the "Form" element and remove it from the "BaseFormElementMixin". Now, the rendering options are only set for the "Form" element and rules as a prototype wide frontend translation setting.

This patch adds a fallback for the form engine translation if there is no "translationFile" setting within the "FormEngine" option.

TYPO3:
  CMS:
    Form:
      prototypes:
        standard:
          formEngine:
            translationFile:
              10: 'EXT:form/Resources/Private/Language/Database.xlf'
              20: 'EXT:ext_form_example1484232130/Resources/Private/Language/Database.xlf'

Now, there is one prototype wide form engine (plugin settings) translation setting.

Summary

With this patch, an integrator has prototype wide translation settings for the 4 aspects of the form framework. Furthermore, the integrator is able to define multiple translation files to avoid copying the whole default translation files or using locallangXMLOverride.

TYPO3:
  CMS:
    Form:
      formManager:
        selectablePrototypesConfiguration:
          1484232130:
            translationFile:
              # translations for the form managers "new form" modal
              10: 'EXT:form/Resources/Private/Language/Database.xlf'
              20: 'EXT:my_ext/Resources/Private/Language/Database.xlf'

      prototypes:
        <prototypeName>:
          formEditor:
            translationFile:
              # translations for the form editor
              10: 'EXT:form/Resources/Private/Language/Database.xlf'
              20: 'EXT:my_ext/Resources/Private/Language/Database.xlf'

          formEngine:
            translationFile:
              # translations for the form plugin (finisher overrides)
              10: 'EXT:form/Resources/Private/Language/Database.xlf'
              20: 'EXT:my_ext/Resources/Private/Language/Database.xlf'

          formElementsDefinition:
            Form:
              renderingOptions:
                translation:
                  translationFile:
                    # translations for the frontend
                    10: 'EXT:form/Resources/Private/Language/locallang.xlf'
                    20: 'EXT:my_ext/Resources/Private/Language/locallang.xlf'

Impact

Easier to use, less maintenance.