• Each row in the image table is configured with an OSid (image.OSid), this points to the id column in the OS table (OS.id)
  • Each row in the OS table is configured with a moduleid (OS.moduleid), this points to the id column in the module table (module.id)
  • The module table contains a column named perlpackage (module.perlpackage), this tells the backend VCL code which Perl module to load and use
  • The module.perlpackage value, the package statement in the Perl module file, and the directory structure of the Perl modules must all align
    • module.perlpackage = VCL::Module::OS::Windows_mod::Version_5::XP_mod
    • lib/VCL/Module/OS/Windows_mod/Version_5/XP_mod.pm: 
      package VCL::Module::OS::Windows_mod::Version_5::XP_mod;
  • Inheritance reduces redundant code
  • Subroutines should reside as high up in the hierarchy as possible
    • This allows all objects which are instantiated as a child class to use the subroutine
  • Child classes can implement subroutines with the same name as one implemented by a parent class
    • The child subroutine in the child class overrides the subroutine in the parent class