- Minimum supported version of Java is now Java 8 (#213)
- Upgrade Groovy to 3.0.8 (#202)
- Deprecated
layout:decoratorprocessor has been deleted (#95) - Deprecated
$DECORATOR_TITLEconstant has been deleted (#95) <head>merging strategies now respect the<title>position by default (#177)- Deprecated
layout:collect - Added an
Automatic-Module-Nameofnz.net.ultraq.thymeleaf.layoutdialect(#171)
Version 3.0 of the layout dialect is largely an upgrade to use Groovy 3.0 which removes the 'reflective access warning' in Java (which is set to become an error in Java 17) and the deletion of code that has been deprecated in version 2.x. It's also a step towards becoming a full Java module, applying an automatic module name and doing some reorganizing of packages in the interim.
I've written a migration guide to help make the assessment of what an upgrade to 3.0 would entail for you. Check it out on the documentation site: https://ultraq.github.io/thymeleaf-layout-dialect/migrating-to-3.0/