Liferay: Understanding portlet:defineObjects

There is so much confusion about the implicit objects provided by <portlet:defineObjects/> tag on JSP as developers cannot see them easily. Experienced developers know what is available and they can use them freely. Here is a cheat sheet for the same.

<portlet:defineObjects/> is an empty tag without any attribute, and must be included after the mentioned directive.

JSR -286 (Portlet 2.0) have objects available from the following 13 objects, depending upon the origin of render, which lies in 3 categories:

1. Request Objects
1. RenderRequest – if the origin of request is from render phase
2. ActionRequest - if the origin of request is from action phase
3. ResourceRequest - if the origin of request is from ajax (serveResource)
4. EventRequest - if the origin of request is from event (processEvent)
2. Response Objects
1. RenderResponse - if the origin of request is from render phase
2. ActionResponse - if the origin of request is from action phase
3. ResourceResponse - if the origin of request is from ajax (serveResource)
4. EventResponse - if the origin of request is from event (processEvent)
3. Portlet Objects
1. PortletConfig
2. PortletSession
3. Map<String, Object> - contains list of all portletSessionAttributes
4. PortletPreferences
5. Map<String, String[]> - contains list of all portletPreferences

That’s all for today. Thanks for reading and have a nice day.