Comment system for Blog

Hello, i’m trying to implement (in open-source version) the new functionality of adding comments under the blog. When executing logic (after form submit) in the doAction() method of cotroller, request.getRequestContext ().GetContentBean() --> returns null, but when executing the doBeforeRender the same method, finds the BlogPost bean from context. What’s the problem guys?

I used the code available here

and I have no idea where I am making a mistake