MESSAGE operator

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

Syntax

MESSAGE expression options

Operator options options can be listed one after another in any order. The following set of options is supported:

syncType
LOG

Description

The MESSAGE operator creates an action that shows a message to the user either as a dialogue box with a text message or in the system window System.log. The text message can be represented either by a string constant or by another more complex expression whose value is a string or a value that can be converted to a string.

Parameters

• expression

  An expression which value is the message text.

• syncType

  Synchronisation type. Specifies when the execution of the created action completes. Specified by one of the keywords:

  • WAIT - after the end of the message showing (in the case of displaying a dialog box with a message - after the window is closed). This value is used by default.

  • NOWAIT - right after the information is ready for sending to the user (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.

• LOG

  A keyword that, when specified, shows the message in the System.log window.

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
// and the third one will be additionally written to the log
testMessage() {
    LOCAL i = INTEGER();
    i() <- 0;
    WHILE i() < 5 DO {
        i() <- i() + 1;
        MESSAGE i();
        IF i() == 3 THEN {
            MESSAGE i() LOG;
        }
    }
}

// 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;
    }
}