[Building Sakai] About the content tool and the permissions helper tool

[Glauber Cabral]

Dear Sakai devs.

This is my first message to the list and I'm developing using sakai2.4.
I need to execute an action when folder permissions are changed in the
Content tool.
As I could see, it uses the permissions.helper tool from authz tool..

I tried to overwrite ToolServlet.sendToHelper inside ResourcesAction
to get permissions before and after the execution of the helper tool.
The problem in this function is that it is called 2 or 3 times before
getting into the helper and 2 or 3 times after leaving the helper and
i could not see any difference in the request and response parameters.

The other method I tried working on was the ResourcesActions.doDispatchAction().
Inside this method there is a call to ToolServlet.startHelper(). So I
tried to get existing permissions before and after this function call.
The problem is that the call returns immediately after setting the
helper tool and not after leaving the helper tool.

I could not find where (inside Content tool) the return from the
helper tool is treated to get the permissions in this place.

Do you have any suggestions about which method should I overwrite? Is
there such a service in another sakai tool that I could use?
I need to code the action inside Content tool.

Thank you a lot for your attention.

Glauber Cabral