Create ObjectFactory class

currently only supports created_by_ref

stix2/__init__.py

@@ -4,6 +4,7 @@
 
 from . import exceptions
 from .bundle import Bundle
+from .environment import ObjectFactory
 from .observables import (URL, AlternateDataStream, ArchiveExt, Artifact,
                           AutonomousSystem, Directory, DomainName,
                           EmailAddress, EmailMessage, EmailMIMEComponent, File,

stix2/environment.py

@@ -0,0 +1,14 @@
+
+class ObjectFactory(object):
+
+    def __init__(self, created_by=None):
+        self.created_by = created_by
+
+    def create(self, cls=None, **kwargs):
+        if cls is None:
+            raise ValueError('No STIX object class provided')
+
+        if self.created_by is not None:
+            kwargs['created_by_ref'] = self.created_by
+
+        return cls(**kwargs)

stix2/test/constants.py

@@ -20,6 +20,12 @@ TOOL_ID = "tool--8e2e2d2b-17d4-4cbf-938f-98ee46b3cd3f"
 SIGHTING_ID = "sighting--bfbc19db-ec35-4e45-beed-f8bde2a772fb"
 VULNERABILITY_ID = "vulnerability--0c7b5b88-8ff7-4a4d-aa9d-feb398cd0061"
 
+# Minimum required args for an Identity instance
+IDENTITY_KWARGS = dict(
+    name="John Smith",
+    identity_class="individual",
+)
+
 # Minimum required args for an Indicator instance
 INDICATOR_KWARGS = dict(
     labels=['malicious-activity'],

stix2/test/test_environment.py

@@ -0,0 +1,16 @@
+import stix2
+
+from .constants import IDENTITY_ID, IDENTITY_KWARGS, INDICATOR_KWARGS
+
+
+def test_object_factory_created_by_ref_str():
+    factory = stix2.ObjectFactory(created_by=IDENTITY_ID)
+    ind = factory.create(stix2.Indicator, **INDICATOR_KWARGS)
+    assert ind.created_by_ref == IDENTITY_ID
+
+
+def test_object_factory_created_by_ref_obj():
+    id_obj = stix2.Identity(id=IDENTITY_ID, **IDENTITY_KWARGS)
+    factory = stix2.ObjectFactory(created_by=id_obj)
+    ind = factory.create(stix2.Indicator, **INDICATOR_KWARGS)
+    assert ind.created_by_ref == IDENTITY_ID