public QuestionBank(XmlResourceParser parser) throws IOException, XmlPullParserException {

        categories = new ArrayList<Category>();

        Category currentCategory = null;

        int eventType = -1;
        while(eventType != XmlResourceParser.END_DOCUMENT){

            if(parser.getEventType() == XmlResourceParser.START_TAG){

                //Log.d("P", " - " + parser.getName());

                switch (parser.getName()){


                    case "category":
                        //Create new category and set as current.
                        currentCategory = new Category();
                        categories.add(currentCategory);

                        //init new category.
                        currentCategory.name = parser.getAttributeValue(null,"name");
                        currentCategory.questions = new ArrayList<Question>();
                        Log.i("Question Bank", "new Category: " + currentCategory.name);

                        break;

                    case "question":
                        Question newQuestion = new Question();

                        newQuestion.questionText = parser.getAttributeValue(null,"text");
                        newQuestion.correctAnswer = Boolean.parseBoolean(parser.getAttributeValue(null,"correct_answer"));

                        currentCategory.questions.add(newQuestion);
                        Log.i("Question Bank", "new Question: " + newQuestion.questionText + " : " + newQuestion.correctAnswer );

                        break;

                    case "question_bank":
                        //do nothing.
                        break;

                    default:
                        Log.e("Question Bank", "Invalid XML tag");
                        break;
                }
            }

            eventType = parser.next();
        }
    }