function handle_attachments() {
    // make sure we have new args before firing
    // prevents handling of the same file every time the app opens, resumes, etc
    args = Ti.App.getArguments();
    var file = args.url;
    var source = args.source;

    // make sure we have something to work with
    if(!file) {
        return false;
    }

    //opening text file
    if( file.indexOf('.txt') != -1 ) {
        curr_note_args = Ti.App.Properties.getString('curr_note_args');
        if(curr_note_args == args.url) {
            return false;
        }
        // DO SOMETHING HERE

        Ti.App.Properties.setString('curr_note_args', args.url);
    }

    // opening wave file
    if( file.indexOf('.wav') != -1 ) {
        curr_audio_args = Ti.App.Properties.getString('curr_audio_args');
        if(curr_audio_args == args.url) {
            return false;
        }
        // DO SOMETHING HERE

        Ti.App.Properties.setString('curr_audio_args', args.url);
    }
}

// Ti doesn't have an 'open' listener for the app so we listen on the main window
b.addEventListener('open', function(e) {
    handle_attachments();
});
Ti.App.addEventListener('resume', function(e) {
    handle_attachments();
});
Ti.App.addEventListener('resumed', function(e) {
    handle_attachments();
});
Ti.App.addEventListener('pause', function(e) {
    handle_attachments();
});