This PR addresses the issues #950 #951

aiida/backends/tests/workflows.py

@@ -144,13 +144,52 @@ def test_workflow_info(self):
                 get_workflow_info(w)
 
     def test_wf_get_state(self):
+        """
+        Simple test that checks the state of the workflows. We create two
+        workflows since the test order in the SQLA was influencing the value
+        of aiida.backends.sqlalchemy.models.workflow.DbWorkflow.state which
+        should be a Choice object, according to the SQLA doc. Sometimes it
+        was automatically converted to unicode.
+
+        Since we are interested to get a unicode from
+        aiida.orm.implementation.general.workflow.AbstractWorkflow#get_state
+        we enforce this conversion at
+        aiida.orm.implementation.sqlalchemy.workflow.Workflow#get_state
+
+        For more info, check issue #951
+        """
+        # Creating two simple workflows & storing them
+        wf1 = WFTestEmpty()
+        wf1.store()
+
+        wf2 = WFTestEmpty()
+        wf2.store()
+
+        # Checking that the get_state doesn't throw exceptions and that
+        # it is a valid state
+        self.assertIn(wf1.get_state(), wf_states)
+        self.assertIn(wf2.get_state(), wf_states)
+
+    def test_wf_ctime(self):
+        import datetime
+        import pytz
+
+        # Get the current datetime (before the creation of the workflow)
+        dt_before = datetime.datetime.now(pytz.utc)
+
         # Creating a simple workflow & storing it
         wf = WFTestEmpty()
         wf.store()
 
-        # Checking that the get_state doesn't throw exceptions and that
-        # it is a valid state
-        self.assertIn(wf.get_state(), wf_states)
+        # Get the current datetime (after the creation of the workflow)
+        dt_after = datetime.datetime.now(pytz.utc)
+
+        self.assertLessEqual(dt_before, wf.ctime, "The workflow doesn't have"
+                                                  "a valid creation time")
+
+        self.assertGreaterEqual(dt_after, wf.ctime, "The workflow doesn't "
+                                                    "have a valid creation "
+                                                    "time")
 
     def test_failing_calc_in_wf(self):
         """

aiida/orm/implementation/django/workflow.py

@@ -157,6 +157,10 @@ def label(self):
     def label(self, label):
         self._update_db_label_field(label)
 
+    @property
+    def ctime(self):
+        return self.dbworkflowinstance.ctime
+
     def _update_db_label_field(self, field_value):
         """
         Safety method to store the label of the workflow

aiida/orm/implementation/general/workflow.py

@@ -137,6 +137,13 @@ def label(self, label):
         """
         pass
 
+    @abstractproperty
+    def ctime(self):
+        """
+        Get the creation time of the workflow
+        """
+        pass
+
     @abstractmethod
     def _update_db_label_field(self, field_value):
         """

aiida/orm/implementation/sqlalchemy/workflow.py

@@ -156,6 +156,10 @@ def label(self):
     def label(self, label):
         self._update_db_label_field(label)
 
+    @property
+    def ctime(self):
+        return self.dbworkflowinstance.ctime
+
     def _update_db_label_field(self, field_value):
         """
         Safety method to store the label of the workflow
@@ -403,7 +407,7 @@ def get_state(self):
         Get the Workflow's state
         :return: a state from wf_states in aiida.common.datastructures
         """
-        return self.dbworkflowinstance.state
+        return unicode(self.dbworkflowinstance.state)
 
     def set_state(self, state):
         """