Using Overloaded Functions to Determine Object Types
Vol 7 Issue 6, p.25

	

Listing 1: nv_pass.of_set( PowerObject )


ll_count = UpperBound( the_str_parm.oc[] )
the_key = lower( trim( the_key ) ) // Trimmed and lowered in of_get() too

// Do we have the key already?
for i = 1 to ll_count
	if the_str_parm.oc[ i ].key = the_key then exit // Yes
next

if i <= ll_count then // The_key exists already
	the_str_parm.oc[ i ].value = the_powerobject
else // The_key does NOT already exist
	// Insert the key-value pair in the next available array element
	the_str_parm.oc[ ll_count + 1 ].key = the_key 
	the_str_parm.oc[ ll_count + 1 ].value = the_powerobject
end if

Listing 2: A typical of_get() variant for string values


	// Boolean of_get( str_parm the_str_parm, string the_key, ref string the_string )
if of_get_ac( the_str_parm, the_key ) then return true 
  // Failed to find the_key
the_string = iany_value // Set in of_get_ac()
return false // Success

Listing 3: Check whether the PowerObject is a GraphicObject before the cast
string f_context( PowerObject the_object, string the_location )
	// Is this is an NVO (or other non-GraphicObject)?
if not g.is_graphic_object( the_object ) then // Yes
  	return the_object.ClassName() + '.' + the_location
	end if

// Set up to loop up the GetParent() hierarchy
lgo_parent = the_object // Here is the cast!

// Loop until we find the enclosing window
do while true // Exit on finding a window
			
	// Add in the parent's ClassName()
	ls_context = lgo_parent.ClassName() + "." + ls_context
				
	// We're done, if we're at the window level
	if lgo_parent.TypeOf() = Window! then 
	  return ls_context + the_location
		end if

	// Get the next parent, i.e. the next layer of the onion, proceeding outward
	lgo_parent = lgo_parent.GetParent()
		
loop