From 94579ab8e28b96de9df2cacab960623034038d76 Mon Sep 17 00:00:00 2001
From: Martin Baeuml <baeuml@kit.edu>
Date: Fri, 13 May 2011 11:07:44 +0200
Subject: [PATCH] import callables where path is given as string

---
 items/factory.py | 32 +++++++++++++++++++++++++++++---
 items/items.py   |  2 +-
 2 files changed, 30 insertions(+), 4 deletions(-)

diff --git a/items/factory.py b/items/factory.py
index 082cf03..58f16e8 100644
--- a/items/factory.py
+++ b/items/factory.py
@@ -1,3 +1,6 @@
+import exceptions
+import importlib
+
 class Factory:
     """
     A generic factory for both items and inserters.
@@ -19,14 +22,35 @@ class Factory:
             for _type, item in items.iteritems():
                 self.register(_type, item, replace=True)
 
+    def import_callable(self, module_path_name):
+        """
+        Import the callable given by ``module_path_name``.
+        """
+        try:
+            module_path, name = module_path_name.rsplit('.', 1)
+        except ValueError:
+            raise exceptions.ImproperlyConfigured('%s is not a valid module path' % module_path_name)
+        try:
+            mod = importlib.import_module(module_path)
+        except ImportError, e:
+            raise exceptions.ImproperlyConfigured('Error importing module %s: "%s"' % (module_path, e))
+        try:
+            item_callable = getattr(mod, name)
+        except AttributeError:
+            raise exceptions.ImproperlyConfigured('Module "%s" does not define a "%s" callable' % (module_path, name))
+
+        return item_callable
+
     def register(self, _type, item, replace=False):
         """
         Register a new type-item mapping.
 
         Parameters
         ==========
-
-
+        _type: string
+            Type of the item.
+        item: python callable or string
+            Reference to the callable which creates the new object.
         """
         _type = _type.lower()
 
@@ -34,6 +58,8 @@ class Factory:
             raise Exception("Type %s already has an item: %s" % \
                              (_type, str(self.items_[_type])))
         else:
+            if type(item) == str:
+                item = self.import_callable(item)
             self.items_[_type] = item
 
     def clear(self, _type=None):
@@ -55,7 +81,7 @@ class Factory:
 
     def create(self, _type, *args, **kwargs):
         """
-        Create a new objectt.
+        Create a new object.
 
         Parameters
         ==========
diff --git a/items/items.py b/items/items.py
index 6104757..3e3888b 100644
--- a/items/items.py
+++ b/items/items.py
@@ -1,6 +1,6 @@
 from PyQt4.QtGui import *
 from PyQt4.Qt import *
-from annotationmodel import DataRole
+from annotations.model import DataRole
 
 class ControlItem(QGraphicsItem):
     def __init__(self, parent=None):