Returning record type in applescript (from objective-C)

Question

I am trying to return an entry in applescript. The current solution is to return an NSDictionary and determine the type of record (Lyx return value) in the sdef file, but this will not work - should I create a specific AppleScript object?

Here is the sdef file

<!-- our special scripting suite for this example -->
<suite name="Lyx" code="LYX " description="LyX scripting facilities.">

    <record-type name="LyX return value" code="LyxR">
        <property name="code" code="code" type="integer"
            description="Error code (0 in case of success).">
            <cocoa key="code"/>
        </property>            
        <property name="message" code="mess" type="text"
            description="The returned message.">
            <cocoa key="message"/>
        </property>
    </record-type>

    <command name="run" code="SLyxComm" description="run a simple command with one parameter">
        <cocoa class="LyxCommand"/>

        <direct-parameter description="The command to be executed.">
            <type type="text" list="no"/>
        </direct-parameter>

        <parameter name="with argument" code="args" type="text">
            <cocoa key="arg"/>
        </parameter>

        <result type="LyX return value" description="Contains a code (0 for success) and the message returned by LyX"/>
    </command>

</suite>

and here is the objective-C code

@interface LyxCommand : NSScriptCommand {
}
- (id)performDefaultImplementation;
@end

@implementation LyxCommand
- (id)performDefaultImplementation {
    // Get the command and argument
    NSDictionary * theArguments = [self evaluatedArguments];

  NSString * directParameter = [self directParameter];
  NSString *arg = [theArguments objectForKey: @"arg"];


  // Execute the command
  LyXFunctionResult result = applescript_execute_command([directParameter UTF8String], [arg UTF8String]);

  // Construct the result record
  NSString *message = [NSString stringWithCString:result.message encoding:NSUTF8StringEncoding];
  free(result.message); 

  NSDictionary *objcResult = [NSDictionary dictionaryWithObjectsAndKeys: [NSNumber numberWithInt:result.code], @"code", message, @"message", nil];
  return objcResult;
}

@end

When I try this simple aplescript

tell application "LyX-2.1-qt4"
set x to (run "server-get-filename" with argument "")
end tell
message of x

error: error "Can’t get message of {message:\"\", code:0}." number -1728 from message of {«class mess»:"", «class code»:0}.

Answer 1

Your sdef and implementation are great, but the terminology that you define in your sdef is NOT available outside of the AppleScript block. Your script should be:

tell application "LyX-2.1-qt4"
    set x to (run "server-get-filename" with argument "")
    message of x
end tell

or, if you really need a message outside the tell block for some reason:

set msg to missing value
tell application "LyX-2.1-qt4"
    set x to (run "server-get-filename" with argument "")
    set msg to message of x
end tell
log msg