Breaking: #73046 - Alias AbstractNode -> ViewHelperNode for backwards compatibility

See forge#73046

Description

ViewHelperInterface::compile() in standalone Fluid now requires an actual ViewHelperNode instead of AbstractNode as it was before. The reason for changing this should be fairly obvious. In order to preserve signature compatibility an alias is put in place.

The alias is created so that TYPO3\CMS\Fluid\Core\Parser\SyntaxTree\AbstractNode becomes an alias of TYPO3Fluid\Fluid\Core\Parser\SyntaxTree\ViewHelperNode. This is obviously less than ideal but solves the problem immediately and prioritises not breaking the public API by breaking the non-public API.

Impact

This signature change means that ViewHelpers which implement a custom compile() method must update their signature (does not apply to ViewHelpers implementing only renderStatic). Two ViewHelpers in TYPO3 CMS Fluid were migrated as part of the standalone Fluid merge - but third-party ViewHelpers would require either migration or an alias.

  • Overridden TemplateParsers (before standalone Fluid merge) might not work, depending on the nature of overrides (conditions checking class names may fail)

  • Custom Nodes (implemented via an overridden TemplateParser, before standalone Fluid) would break either in function or form (incompatible constructor signatures on PHP7 at least)

Affected Installations

Any TYPO3 site using an extension which replaces or directly interacts with TemplateParser or TemplateCompiler from Fluid. Only known affected community extension is at this point EXT:builder, specifically the template validation/analysis feature.

Migration

Change any reference to classes in TYPO3\CMS\Fluid\Core\TemplateParser to TYPO3Fluid\Fluid\Core\TemplateParser.