The app is cloud-hosted - it is not "distributed" to users. It is required that users of the app shall need to purchase a license from the vendor in order to use it.
I am completely new to software licensing and am not sure which ExtJS license is required/preferable, i.e the commercial license or the GNU GPL license?
I have a few questions to hopefully help clarify:
Is it possible to use the GPL license or similar allowing only part of the app's source to be distributable, e.g. the Extjs components, but not allow users to see other components of the system? i.e. the Spring MVC, hibernate server components? Is it possible to restrict access to the ExtJS source if using a GPL license? In general is it possible to restrict distribution of some aspects of the source when using GPL?
If the GPL license is acquired, is the source available only to users of the system or is it open to the whole general public?