4. Notes

GUI interaction

When using scripting addition commands that require GUI access (e.g. display_dialog) targeted at the command-line Ruby interpreter, the osax module will automatically convert the non-GUI interpreter process into a full GUI process to allow these commands to operate correctly. If you want to avoid this, target these commands at a faceless GUI application such as System Events instead:

sa = OSAX.osax("StandardAdditions", "System Events")
sa.activate # give focus to System Events
p sa.display_dialog("Ruby says hello!",
                    :buttons=>["Hi!", "Howdy!", "Duuuude!"],
                    :default_button=>3)
# Result: {:button_returned=>"Duuuude!"}

64-bit limitations

The OSAX module currently only supports dynamic retrieval of scripting addition terminology when running in 32-bit processes. To use it in 64-bit processes, use the Terminology module's dump method to export a static terminology 'glue' module for the desired scripting addition (running it in a 32-bit process), then import that module and pass it as the second argument to the ScriptingAddition class's initialiser. For example, to export a glue module for Standard Additions:

require 'appscript'

Terminology.dump('/System/Library/ScriptingAdditions/StandardAdditions.osax', 
        'StandardAdditions', 'standard_additions.rb')

To create a new ScriptingAddition instance using the terminology provided by this glue module:

require 'osax'
require 'standard_additions'

sa = OSAX::ScriptingAddition.new('StandardAdditions', StandardAdditions)

Known problems

When using the OSAX module within RubyCocoa-based applications, avoid creating ScriptingAddition instances before the main event loop is started as this can result in the application behaving strangely (minimised windows don't expand correctly) due to a bug in OS X's OSAGetAppTerminology function.