move specs.Assign to operators.

SpiffWorkflow/operators.py

@@ -46,6 +46,48 @@ def deserialize(cls, serializer, s_state):
         """
         return serializer._deserialize_attrib(self, s_state)
 
+class Assign(object):
+    """
+    Assigns a new value to an attribute. The source may be either
+    a static value, or another attribute.
+    """
+
+    def __init__(self,
+                 left_attribute,
+                 right_attribute = None,
+                 right = None,
+                 **kwargs):
+        """
+        Constructor.
+
+        @type  left_attribute: str
+        @param left_attribute: The name of the attribute to which the value
+                               is assigned.
+        @type  right: object
+        @param right: A static value that, when given, is assigned to
+                      left_attribute.
+        @type  right_attribute: str
+        @param right_attribute: When given, the attribute with the given
+                                name is used as the source (instead of the
+                                static value).
+        @type  kwargs: dict
+        @param kwargs: See L{SpiffWorkflow.specs.TaskSpec}.
+        """
+        if not right_attribute and not right:
+            raise ValueError('require argument: right_attribute or right')
+        assert left_attribute is not None
+        self.left_attribute  = left_attribute
+        self.right_attribute = right_attribute
+        self.right           = right
+
+    def assign(self, from_obj, to_obj):
+        # Fetch the value of the right expression.
+        if self.right is not None:
+            right = self.right
+        else:
+            right = from_obj.get_attribute(self.right_attribute)
+        to_obj.set_attribute(**{str(self.left_attribute): right})
+
 def valueof(scope, op):
     if op is None:
         return None

SpiffWorkflow/specs/__init__.py

@@ -12,7 +12,6 @@
 from Simple import Simple
 from StartTask import StartTask
 from SubWorkflow import SubWorkflow
-from Assign import Assign
 from ThreadMerge import ThreadMerge
 from ThreadSplit import ThreadSplit
 from Trigger import Trigger

SpiffWorkflow/storage/XmlSerializer.py

@@ -62,7 +62,7 @@ def _deserialize_assign(self, workflow, start_node):
             kwargs['right'] = value
         else:
             kwargs['right_attribute'] = attrib
-        return specs.Assign(name, **kwargs)
+        return operators.Assign(name, **kwargs)
 
     def _deserialize_property(self, workflow, start_node):
         """