Changes between Initial Version and Version 1 of code/howto/Super

Timestamp:

Oct 10, 2008, 4:03:54 AM (17 years ago)

Author:

landauf

Comment:

—

code/howto/Super

@@ +1 @@
+= HowTo: Super =
+[[TracNav(TracNav/TOC_Development)]]
+
+== Description ==
+SUPER is a macro defined in {{{core/Super.h}}}. It's capable to call a function in the parent class of another class. This avoids class-hierarchy-dependend code like {{{MyParentClass::function();}}}. Instead we use {{{SUPER(MyClass, function);}}}. As you can see, the super-call depends only on the current class. If the parent changes, we don't have to modify the code.
+
+'''Important''': A super-function must be virtual and public. If you don't declare the function {{{public}}} you'll get a compiler error complaining about the private nature of the function.
+
+[wiki:Super] explains in detail how to add a new super-function.
+
+== Usage ==
+This is how you call the SUPER macro:
+ * '''SUPER('''''MyClass, functionname, arguments...''''')''';
+''MyClass'' is the name of the class implementing this function.[[br]]
+''functionname'' is the name of the super-function.[[br]]
+''arguments'': The arguments passed to the function. If the function takes no arguments, SUPER gets called with only 2 parameters (''MyClass'' and ''functionname'').
+
+== Example ==
+This is an example how to use SUPER:
+
+*.h file:
+{{{
+#include "core/BaseObject.h"
+
+class MyClass : public BaseObject
+{
+    public:
+        virtual void XMLPort(Element& xmlelement, XMLPort::Mode mode);
+};
+}}}
+
+*.cc file:
+{{{
+void MyClass::XMLPort(Element& xmlelement, XMLPort::Mode mode)
+{
+    SUPER(MyClass, XMLPort, xmlelement, mode);
+
+    doSomething();
+    ...
+}
+}}}