From eb239b6dac8983af9b4169332b6312aeba2c5f7b Mon Sep 17 00:00:00 2001
From: "W. Trevor King" <wking@tremily.us>
Date: Tue, 5 Feb 2013 10:58:40 -0500
Subject: [PATCH] Add question class storage (lookups in QUESTION_CLASS)

This allows us to specify questions with alternate processing classes.
As a simple example, I've added NormalizedStringQuestion, which
softens the string comparison used in the basic Question.  The next
step is to add a command-line question ;).
---
 quiz.json           |  3 ++-
 quizzer/question.py | 27 +++++++++++++++++++++++++++
 quizzer/quiz.py     | 10 ++++++++--
 3 files changed, 37 insertions(+), 3 deletions(-)

diff --git a/quiz.json b/quiz.json
index 1789fd6..9677dba 100644
--- a/quiz.json
+++ b/quiz.json
@@ -15,8 +15,9 @@
 				]
 		},
 		{
+			"class": "NormalizedStringQuestion",
 			"prompt": "What is your favourite color?",
-			"answer": "Blue",
+			"answer": "blue",
 			"hint": "Channel Sir Lancelot",
 			"dependencies": [
 				"What is your quest?"
diff --git a/quizzer/question.py b/quizzer/question.py
index e423adf..10ae4fd 100644
--- a/quizzer/question.py
+++ b/quizzer/question.py
@@ -1,3 +1,10 @@
+QUESTION_CLASS = {}
+
+
+def register_question(question_class):
+    QUESTION_CLASS[question_class.__name__] = question_class
+
+
 class Question (object):
     def __init__(self, id=None, prompt=None, answer=None, help=None,
                  dependencies=None):
@@ -36,3 +43,23 @@ class Question (object):
 
     def check(self, answer):
         return answer == self.answer
+
+
+class NormalizedStringQuestion (Question):
+    def normalize(self, string):
+        return string.strip().lower()
+
+    def check(self, answer):
+        return self.normalize(answer) == self.normalize(self.answer)
+
+
+for name,obj in list(locals().items()):
+    if name.startswith('_'):
+        continue
+    try:
+        subclass = issubclass(obj, Question)
+    except TypeError:  # obj is not a class
+        continue
+    if subclass:
+        register_question(obj)
+del name, obj
diff --git a/quizzer/quiz.py b/quizzer/quiz.py
index c3fa5a5..7c49e94 100644
--- a/quizzer/quiz.py
+++ b/quizzer/quiz.py
@@ -28,14 +28,20 @@ class Quiz (list):
             raise NotImplementedError('upgrade from {} to {}'.format(
                     version, __version__))
         for state in data['questions']:
-            q = _question.Question()
+            question_class_name = state.pop('class', 'Question')
+            question_class = _question.QUESTION_CLASS[question_class_name]
+            q = question_class()
             q.__setstate__(state)
             self.append(q)
 
     def save(self, **kwargs):
+        questions = []
+        for question in self:
+            state = question.__getstate__()
+            state['class'] = type(question).__name__
         data = {
             'version': __version__,
-            'questions': [question.__getstate__() for question in self],
+            'questions': questions,
             }
         with self._open(mode='w', **kwargs) as f:
             _json.dump(
-- 
2.26.2