To be picky, PCML doesn't make the call n-tier. The toolbox does that (more specifically the ProgramCall class which acts as a wrapper over the OS/400 host server). PCML is simply a shorthand way of invoking the toolbox classes. It externalizes the program information in an XML file and makes processing a call a little easier for the programmer (especially as far as data conversion). There is actually a second generation of this technique called XPCML which uses a well-formed XML document. Joe
From: David Gibbs web400@xxxxxxxxxxxxxxxx wrote:Forgive my ignorance... but what's the point of PCML? Why not simply call an RPG service program as a native method? Or use SQL and make it a UDF? Or a stored procedure?It let's you call programs (at least when using java) without regard to where caller is running.