I can override some Portlet struts actions, but not the EditGroupAction for when a site is edited.
The attached hook project is successfully invoked for the render() action, but fails with an NPE when the user clicks save. Since other portlet actions override quite well, I'm wondering if this has anything to do with security, since this portlet lives in the Control Panel.
1) Deploy (or recreate) the attached Hook project to Portal v6.1.20
2) Edit a site via the Control Panel
3) Verify the "Edit Site" page comes up correctly.
4) Click the "Save" button and receive this error page: The webpage at http://localhost:8080/group/control_panel/manage?p_auth=elhB9KZ4&p_p_id=165&p_p_lifecycle=1&p_p_state=maximized&p_p_mode=view&doAsGroupId=10810&refererPlid=10852&_165_struts_action=%2Fsite_settings%2Fedit_site might be temporarily down or it may have moved permanently to a new web address
Log output (from clicking 'Save') attached.
Blog article guiding my actions so far: http://www.liferay.com/de/web/mika.koivisto/blog/-/blogs/overriding-and-adding-struts-actions-from-hook-plugins