MESSAGE operator

The MESSAGE operator creates an action that shows the user a message.

Syntax

MESSAGE expression [syncType]

Description

The MESSAGE operator creates an action which shows a window with a text message to the user. The text message can be a string constant or a more complex expression which value is or can be converted to a string.

Parameters

• expression

  An expression which value is the message text.

• syncType

  Specifies when the created action should be completed:

  • WAIT - after the client completes the action (closes the message). This value is used by default.
  • NOWAIT - right after the information is ready for sending to the client (the message text is read). If several MESSAGE NOWAIT actions are called during the execution of some continuous action, they do not create separate messages but are concatenated with the previous messages of the same type. A single concatenated message will be shown to the user at the end of the continuous action as a result.

Examples

message { MESSAGE 'Hello World!'; } // plain text message

isGood = DATA BOOLEAN (Item);
stringData(Item i)   {
    // depending on which item will be passed to the action, a window will be shown either 
    // with the text 'Good' or with the text 'Bad'
    MESSAGE IF isGood(i) THEN 'Good' ELSE 'Bad';   
}

// In this case, five text messages will be shown to the user
testMessage()  {   
    LOCAL i = INTEGER();
    i() <- 0;
    WHILE i() < 5 DO {
        i() <- i() + 1;
        MESSAGE i();
    }
}

// In the case of NOWAIT, one text message combining messages from five MESSAGE calls will be shown to the user
testMessageNowait()  {              
    LOCAL i = INTEGER();
    i() <- 0;
    WHILE i() < 5 DO {
        i() <- i() + 1;
        MESSAGE i() NOWAIT;
    }
}