Class
[Object: Dynamic Object Class Framework]


Detailed Description

This file defines a class messaging system reminiscent of traditional OO-style setter and getter interfaces to object properties. A C-language object can declare a collection of setters and getters on itself that can then be used to perform run-time (as opposed to compile-time) bindings to the object.

To put it differently, a QOF class is a set of parameter getters and setters that are associated with an object type. Given a pointer to some thing, the setters and getters can be used to get and set values out of that thing. Note that the pointer to "some thing" need not be a pointer to a QOF Entity or Instance (although QOF classes are more interesting when used with Entities/Instances). What "some thing" is defined entirely by the programmer declaring a new QOF Class.

Because a QOF Class associates getters and setters with a type, one can then ask, at run time, what parameters are associated with a given type, even if those parameters were not known at compile time. Thus, a QOF Class is sort-of like a DynAny implementation. QOF classes can be used to provide "object introspection", i.e. asking object to describe itself.

The QOF Query subsystem depends on QOF classes having been declared; the Query uses the getters to get values associated with particular instances.

A QofAccessFunc or QofSetterFunc do not need to be public functions, if you need to add functions to an object with an established API, define the additional QOF routines as static. Only the register routine needs to be public.


Files

file  qofclass.h
 API for registering paramters on objects.

Defines

#define QOF_MOD_CLASS   "qof-class"


Generated on Fri May 12 17:57:22 2006 for QOF by  doxygen 1.4.4