How can I add a dynamic header to all pages?
If I create a header template I can include it in all views, but I
don't know how to go about including the data handling routine to all
the controllers.
Can I create a dedicated controller for this and let all other
controllers inherit from
Why don't you mix it? Create a component that handles the logic to
obtain the data that should be available on all views. Then add that
component to $components in your AppController. Then, on the
beforeRender() method of your AppController interact with your
component and finally set the data