Changed

The Changed attribute stores whether a value of the variable has changed since the last rule check pass.

Syntax

Changed

Return value

ValueChanged

Parameter

None

ValueChanged	Description
0 – IsNotChanged	The value has not been changed since the last rule check
1 – IsChanged	The value has been changed since the last rule check
2 – DontKnow	The object of the value has not been changed, but the object has been accessed (for complex variable Types)

Features (class variables) and local variables are considered differently:

Features:

- Features are set with Changed = 1 when created, even if they have not been initialized.

- After performing a rule check, all Changed markings of all features are reset.

- Between two rule passes, all features modified by successful assignments are logged. If the queried feature is found in this log list, the value IsChanged is returned. Otherwise, the return value is 0. Please note that a feature is also logged by reassigning the previous value! After a rule check, the log list is deleted.

Local variables:

- Local variables always return 0. No changes are logged.

Remark:

The attribute is read only.