The use of a Definition File allows a single Subprogram call to define the
complete configuration of Verbs, Qualifiers and Retained Menus. Furthermore, it
allows this configuration to be modified without recompiling and rebuilding the
Application Code. Thus the descriptive text on a particular Menu Button may be
modified within the File and the Application Program will implement this
modification the next time it is executed. Note that the Verbs, Qualifiers
and Menus defined via a Definition File may be modified during the execution
of an Application Program using the Subprogram Interface described earlier.
A Definition File may be used to define absolute IDs for Verb Groups or Menus,
or it may be used in a modular programming environment to define self-relative
Group and Menu IDs. Thus an application program may consist of several modules,
each of which wishes to use a Definition File. If only absolute IDs were
available, each module designer would have to arrange with the designers of
the other modules for a ``Block" of Group and Menu IDs to be preassigned. In
order to avoid this, in self-relative mode the Groups and Menus are defined
relative to a base ID, being the first unassigned ID at the time the
definition file is read. The application program may then determine
the range of absolute Group and Menu IDs actually assigned to the module.
A Definition File is just a normal text file that can be build with a text
editor. The default file extension is .UID, and the format of a Definition
File is discussed in detail in Chapter 7.
Definition Files may themselves reference other Definition Files, where such
references may be nested up to a maximum of 4 deep. The syntax for such nesting
is the same as that for Indirect Command Files.