VarIsEmpty

The VarIsEmpty function returns the boolean value of True if the variant variable or field V is unassigned.

This is not normally used with Statelake unless work is being done with locally declared variables.

Variant fields from Data Definitions will be initialised to null, and therefore can never be unassigned - therefore the VarIsNull function should be used to test these fields. Please refer to VarIsNull.

The VarIsEmpty function is also unable to detect whether a variant with a COM reference assigned to it has been cleared. For this, please refer to the VarIsClear function.

Declaration: Function VarIsEmpty(const V : Variant) : Boolean;

A simple example would be as follows.

procedure OnMapEvent(var Value:Variant);
begin
  Value := VarIsEmpty(Field.Value)
end;

This can also be seen through the following code.

procedure ScriptEvent (var Value : variant);
var
  aVar : variant;
  ConfYN : boolean;
begin
  LogInfo('');
  ConfYN := VarIsEmpty(aVar);
  If ConfYN = True then
    LogInfo('The variant variable aVar is EMPTY')
  else
    LogInfo('The variant variable aVar has been ILITIALISED');
  LogInfo('');
 
  aVar := 'Hello, how is the weather?';
    ConfYN := VarIsEmpty(aVar);
  If ConfYN = True then
    LogInfo('The variant variable aVar is still EMPTY')
  else
    LogInfo('The variant variable aVar has NOW been INITIALISED');
  LogInfo('');
  
  aVar := null;
  ConfYN := VarIsEmpty(aVar);
  If ConfYN = True then
    LogInfo('The variant variable aVar is still EMPTY - it is NULL')
  else
    LogInfo('The variant variable aVar has NOW been INITIALISED - it is NULL');
  LogInfo('');
 
end;