Deprecation: #67737 - TCA: Drop additional palette 

Description 

The showitem string of TCA types allowed to define an "additional palette" as third semicolon separated name of a field. Such a palette was then rendered after the main field. This handling has been dropped and existing "additional palettes" were migrated to a "normal" palette definition directly after the field.

Before:

'types' => array(
	'aType' => array(
		'showitem' => 'aField;aLabel;anAdditionalPaletteName',
	),
),

The behavior before was: If the field aField is rendered, then the palette anAdditionalPaletteName is rendered, too. This functionality has been dropped, the migrated field now looks like this:

'types' => array(
	'aType' => array(
		'showitem' => 'aField;aLabel, --palette--;;anAdditionalPaletteName',
	),
),

A casual field name in showitem now only has a label override as additional information, like aField;aLabel, while a palette is referenced as --palette--;aLabel;paletteName.

Impact 

All extensions that use "additional palette" syntax are migrated to the new syntax, but will throw a deprecation message.

The "additional palette" handling was sometimes misused as "poor-mans-access-control": If access to the main field was not allowed, the palette fields were not rendered either. This changed, the main field and the palette are decoupled, it may happen that additional fields are now rendered for users that should not have access to it. Adapting the exclude config definition of the palette fields and user or group access records is necessary in those cases.

Affected Installations 

Extensions that use the "additional palette" handling.

Migration 

An automatic migration is in place and logged to typo3conf/deprecation_*. The migration code will be dropped with TYPO3 CMS 8, a manual fix of the according showitem field is required, the deprecation log gives detailed information on how the definition should look like.