isvalid

Determine if message is valid

Syntax

isvalid(message_name)

Description

isvalid(message_name) checks if an input or local message is valid. A message is valid if the chart has removed it from the queue and has not forwarded or discarded it.

Examples

Check Message in State Action

When state A is active, receive message M. If the message has a data value equal to 3, discard the message. Then, when state B is active, check that the message M is still valid. If the message is valid and has a data value equal to 6, discard the message.

In state A:

during:
   if receive(M) == true
      if M.data == 3
         discard(M);
      end
   end

In state B:

during:
   if isvalid(M) == true
      if M.data == 6
         discard(M);
      end
   end