1 files changed, 14 insertions, 21 deletions
diff --git a/ReckonPrimer.activity/collection.py b/ReckonPrimer.activity/collection.py
index 53ababe..4a45bd1 100644
--- a/ReckonPrimer.activity/collection.py
+++ b/ReckonPrimer.activity/collection.py
@@ -10,12 +10,9 @@ from sugar.graphics import style
 from settings import Settings
 from coach import Coach
 
-from exaddsimp import ExAddSimp
-from exaddsub import ExAddSub
-from expassten import ExPassTen
-from exmult import ExMult
-from extimesdiv import ExTimesDiv
-from extimesadd import ExTimesAdd
+from exercises import *
+from exercises.exercise import Exercise
+
 
 class Collection:
 
@@ -31,24 +28,20 @@ class Collection:
         self._active_exerc = None
 
     def select(self, key):
-        """ Select an exercise by key.
+        """ Select an exercise by key. return instance of an exercise.
         Errors are retrieved for (future) use by Coach. """
         #WN.LV Code ersetzen: key ist dann fuer Listen von Listen !!
         (_sett, _errors) = self._data[key]
-        if _sett['topic'] == 'addsub_simp':
-            return ExAddSimp(self._display, (_sett, _errors))
-        elif _sett['topic'] == 'exaddsub':
-            return ExAddSub(self._display, (_sett, _errors))
-        elif _sett['topic'] == 'passten':
-            return ExPassTen(self._display, (_sett, _errors))
-        elif _sett['topic'] == 'exmult':
-            return ExMult(self._display, (_sett, _errors))
-        elif _sett['topic'] == 'times_div':
-            return ExTimesDiv(self._display, (_sett, _errors))
-        elif _sett['topic'] == 'extimesadd':
-            return ExTimesAdd(self._display, (_sett, _errors))
-        else:
-            raise Exception()
+        exercise_label = _sett['topic']
+
+        if not Exercise.EXERCISES.has_key(exercise_label):
+            raise Exception('Collection#select: Wrong key. To register an exercise see exercises/__init__.py')
+    
+        klass = Exercise.EXERCISES[exercise_label]
+        package = __import__("exercises." + klass)
+        module = getattr(package, klass)
+        return getattr(module, klass)(self._display, (_sett, _errors))    
+
 
     def define_coll_gui(self):
         """ Define gui-elements for presenting the collection.