$CLASSMETHOD enables you to run a class method, given as class name and method name. For example:
TESTNAMESPACE>set class="Sample.Person"
TESTNAMESPACE>set obj=$CLASSMETHOD(class,"%OpenId",1)
TESTNAMESPACE>w obj.Name
Van De Griek,Charlotte M.
This function is useful when you need to write generic code that executes a class method, but the class name (or even the method name) is not known in advance. For example:
//read name of class from imported document
Set class=$list(headerElement,1)
// create header object
Set headerObj=$classmethod(class,"%New")
The other functions are useful in similar scenarios.