There are some migration steps to do, dependent on the application you want to migrate. The steps can be classified by

Here is a simple , that may help you to change the layout attributes in the facelets XHTML files.

TobagoContext.getResourceBundle() returns now ResourceBundle TobagoContext.getMessageBundle() returns now ResourceBundle For local menu for the suggest box use `localMenu="true"` in `<tc:suggest>` instead of `markup="localMenu"` in the `<tc:in>`. The attribute `placehoder` in `<tc:file>` has been removed, because its not supported with Bootstrap 5. The attribute `applicatonIcon` in `<tc:page>` has been removed. Please use the `<tc:metaLink>` tag instead.

- Completely refactored
- Support for HTML input types: date, time, datetime-local
- Droped support for java.util.Calendar
- Replace <tc:convertDateTime> with <f:convertDateTime>

On form components `labelLayout='skip'` could be used in Tobago 4 to remove the bottom margin. The new attribute `autoSpacing` replace this. By default it's 'true' and a bottom margin is set on form components. Use `autoSpacing='false'` to remove the margin. Using Bootstrap Icons and drop FontAwesome. The constants in enum `org.apache.myfaces.tobago.renderkit.css.Icons` has been changed to the names used by Bootstrap Icons. Tobago.registerListener(Demo.init, Tobago.Phase.DOCUMENT_READY); Tobago.registerListener(Demo.init, Tobago.Phase.AFTER_UPDATE);