Rework ListProperty, fix merging issues

stix2/common.py

@@ -12,7 +12,7 @@ COMMON_PROPERTIES = {
     'external_references': Property(),
     'revoked': BooleanProperty(),
     'created_by_ref': ReferenceProperty(type="identity"),
-    'object_marking_refs': ListProperty(ReferenceProperty, element_type="marking-definition"),
+    'object_marking_refs': ListProperty(ReferenceProperty(type="marking-definition")),
     'granular_markings': ListProperty(Property)
 }
 

stix2/markings.py

@@ -5,14 +5,21 @@ from .properties import IDProperty, TypeProperty, ListProperty, ReferencePropert
 from .utils import NOW
 
 
+class GranularMarking(_STIXBase):
+    _properties = {
+        'marking_ref': ReferenceProperty(required=True, type="marking-definition"),
+        'selectors': ListProperty(SelectorProperty, required=True),
+    }
+
+
 class MarkingDefinition(_STIXBase):
     _type = 'marking-definition'
     _properties = {
         'created': Property(default=lambda: NOW),
         'external_references': Property(),
         'created_by_ref': ReferenceProperty(type="identity"),
-        'object_marking_refs': ListProperty(ReferenceProperty, element_type="marking-definition"),
-        'granular_marking': ListProperty(Property, element_type="granular-marking"),
+        'object_marking_refs': ListProperty(ReferenceProperty(type="marking-definition")),
+        'granular_marking': ListProperty(GranularMarking),
         'type': TypeProperty(_type),
         'id': IDProperty(_type),
         'definition_type': Property(),
@@ -20,13 +27,6 @@ class MarkingDefinition(_STIXBase):
     }
 
 
-class GranularMarking(_STIXBase):
-    _properties = {
-        'marking_ref': ReferenceProperty(required=True, type="marking-definition"),
-        'selectors': ListProperty(SelectorProperty, required=True),
-    }
-
-
 class TLPMarking(_STIXBase):
     # TODO: don't allow the creation of any other TLPMarkings than the ones below
     _properties = {

stix2/properties.py

@@ -4,6 +4,7 @@ from six import PY2
 import datetime as dt
 import pytz
 from dateutil import parser
+import inspect
 from .base import _STIXBase
 
 
@@ -77,45 +78,31 @@ class Property(object):
             pass
         return value
 
+    def __call__(self, value=None):
+        if value is not None:
+            return value
+
 
 class ListProperty(Property):
 
-    def __init__(self, contained, element_type=None, **kwargs):
+    def __init__(self, contained, **kwargs):
         """
-        contained should be a type whose constructor creates an object from the value
+        Contained should be a function which returns an object from the value.
         """
         if contained == StringProperty:
             self.contained = StringProperty().string_type
         elif contained == BooleanProperty:
             self.contained = bool
+        elif inspect.isclass(contained) and issubclass(contained, Property):
+            # If it's a class and not an instance, instantiate it so that
+            # validate() can be called on it, and ListProperty.validate() will
+            # use __call__ when it appends the item.
+            self.contained = contained()
         else:
             self.contained = contained
-        self.element_type = element_type
         super(ListProperty, self).__init__(**kwargs)
 
     def validate(self, value):
-        try:
-            list_ = self.clean(value)
-        except ValueError:
-            raise
-
-        # STIX spec forbids empty lists
-        if len(list_) < 1:
-            raise ValueError("must not be empty.")
-
-        try:
-            for item in list_:
-                self.contained.validate(item)
-        except ValueError:
-            raise
-        except AttributeError:
-            # type of list has no validate() function (eg. built in Python types)
-            # TODO Should we raise an error here?
-            pass
-
-        return list_
-
-    def clean(self, value):
         try:
             iter(value)
         except TypeError:
@@ -124,14 +111,23 @@ class ListProperty(Property):
         result = []
         for item in value:
             try:
-                if type(item) is dict:
-                    result.append(self.contained(**item))
-                elif isinstance(item, ReferenceProperty):
-                    result.append(self.contained(type=self.element_type))
-                else:
-                    result.append(self.contained(item))
-            except TypeError:
-                raise ValueError("the type of objects in the list must have a constructor that creates an object from the value.")
+                valid = self.contained.validate(item)
+            except ValueError:
+                raise
+            except AttributeError:
+                # type of list has no validate() function (eg. built in Python types)
+                # TODO Should we raise an error here?
+                valid = item
+
+            if type(valid) is dict:
+                result.append(self.contained(**valid))
+            else:
+                result.append(self.contained(valid))
+
+        # STIX spec forbids empty lists
+        if len(result) < 1:
+            raise ValueError("must not be empty.")
+
         return result
 
 

stix2/sro.py

@@ -45,8 +45,8 @@ class Sighting(_STIXBase):
         'last_seen': Property(),
         'count': Property(),
         'sighting_of_ref': ReferenceProperty(required=True),
-        'observed_data_refs': ListProperty(ReferenceProperty, element_type="observed-data"),
-        'where_sighted_refs': ListProperty(ReferenceProperty, element_type="identity"),
+        'observed_data_refs': ListProperty(ReferenceProperty(type="observed-data")),
+        'where_sighted_refs': ListProperty(ReferenceProperty(type="identity")),
         'summary': Property(),
     })