OpenMarkov Exceptions

{Merge and distribute with localization}

OpenMarkov exceptions use a specific frame to display a Swing error message and to access the text that should go into that message.

Imagine that you catch a NullPointerException and you want to tell the user that there is no free lunch:

Modyfing the text for the exception

1. Add the text you want to show the user (title and message) to the xml string database that adresses localization:
   1. In the plugin package that throws the exception
   2. In the gui package otherwise
2. The exception should be formatted as it's here:

       <Reality>
           <NoFreeLunch>
               <title value="No free lunch"/>
               <message value="Nothing is free and lunch above everything"/>
           </NoFreeLunch>
       </Reality>
   

   Note that the token of this exception will be the list of enclosing fields separated by dots: Reality.NoFreeLunch

Creating the exception

1. Now create an OpenMarkovException with the token as argument.
2. Wrap this exception by a LocalizedException with the OpenMarkovException as first argument and the parent GUI component as second (you don't throw the localized exception)
3. The LocalizedException.showException() method will show an error message with the title and the body (message) from the xml.

The complete java code for the example above is:

catch(NullPointerException e)  {
    LocalizedException NoFreeLunchException = new LocalizedException(new OpenMarkovException("Reality.NoFreeLunch"), this);
    NoFreeLunchException.showException();
}

Formatted message

OpenMarkovException formats strings the same way than System.out.printf does: OpenMarkovException("No %s, then no %s, "lunch", "work"). But it only allows string arguments. The placeholder allow different commands:

%-5s

% Beginning of format
- OPTIONAL. Use left-justification on minimal whitespaces. See below.
5 Minimum whitespaces for the print. Right-justifies. Empty means 0.
s Type code (string coerced)