hookDisplayBackOfficeHeader() not called - and now?

[musicmaster]

Never having been a fan of object oriented programming I finally am getting serious about writing a Prestashop module. And I am immediately running into obstacles.

 

I am writing a configuration routine (that is: back office) that uses Javascript. Of course I could just throw the Javascript into my code or throw a "<script src=" somewhere in the html. But I try to do it according to protocol.

 

So it seemed to me that "hookDisplayBackOfficeHeader()" is the right place to write "$this->context->controller->addJS($this->_path.'myscript.js');". Wrong... It looks like the routine is not even called. So where should I put my code instead?