Merge pull request #2870 from dannon/histories.most_recent_v_default

Create a new trans method for getting the most recently touched history.

lib/galaxy/web/framework/webapp.py

@@ -660,7 +660,7 @@ class GalaxyWebTransaction( base.DefaultWebTransaction,
                     users_last_session.current_history.deleted):
                 history = users_last_session.current_history
             elif not history:
-                history = self.get_history( create=True )
+                history = self.get_history( create=True, most_recent=True )
             if history not in self.galaxy_session.histories:
                 self.galaxy_session.add_history( history )
             if history.user is None:
@@ -708,10 +708,11 @@ class GalaxyWebTransaction( base.DefaultWebTransaction,
         """
         return self.galaxy_session
 
-    def get_history( self, create=False ):
+    def get_history( self, create=False, most_recent=False ):
         """
-        Load the current history, creating a new one only if there is not
-        current history and we're told to create.
+        Load the current history.
+            - If that isn't available, we find the most recently updated history.
+            - If *that* isn't available, we get or create the default history.
         Transactions will not always have an active history (API requests), so
         None is a valid response.
         """
@@ -719,6 +720,8 @@ class GalaxyWebTransaction( base.DefaultWebTransaction,
         if self.galaxy_session:
             if hasattr( self.galaxy_session, 'current_history' ):
                 history = self.galaxy_session.current_history
+        if not history and most_recent:
+            history = self.get_most_recent_history()
         if not history and util.string_as_bool( create ):
             history = self.get_or_create_default_history()
         return history
@@ -764,6 +767,23 @@ class GalaxyWebTransaction( base.DefaultWebTransaction,
 
         return history
 
+    def get_most_recent_history( self ):
+        """
+        Gets the most recently updated history.
+        """
+        # There must be a user to fetch histories, and without a user we have
+        # no recent history.
+        if not self.galaxy_session.user:
+            return None
+        try:
+            recent_history = self.sa_session.query( self.app.model.History ).filter_by(
+                user=self.galaxy_session.user,
+                deleted=False ).order_by(self.app.model.History.update_time.desc()).first()
+        except NoResultFound:
+            return None
+        self.set_history(recent_history)
+        return recent_history
+
     def new_history( self, name=None ):
         """
         Create a new history and associate it with the current session and

lib/galaxy/webapps/galaxy/controllers/history.py

@@ -487,7 +487,7 @@ class HistoryController( BaseUIController, SharableMixin, UsesAnnotations, UsesI
             history = self.history_manager.get_accessible( self.decode_id( id ), trans.user,
                 current_history=trans.history )
         else:
-            history = trans.get_history( create=True )
+            history = trans.get_history( most_recent=True, create=True )
 
         trans.response.set_content_type( 'text/xml' )
         return trans.fill_template_mako(
@@ -1351,7 +1351,7 @@ class HistoryController( BaseUIController, SharableMixin, UsesAnnotations, UsesI
         """Return the current user's current history in a serialized, dictionary form."""
         # Prevent IE11 from caching this
         trans.response.headers[ 'Cache-Control' ] = ["max-age=0", "no-cache", "no-store"]
-        history = trans.get_history( create=True )
+        history = trans.get_history( most_recent=True, create=True )
         return self.history_data( trans, history )
 
     @web.json

lib/galaxy/webapps/galaxy/controllers/visualization.py

@@ -955,7 +955,7 @@ class VisualizationController( BaseUIController, SharableMixin, UsesVisualizatio
         """
         regions = regions or '{}'
         # Need to create history if necessary in order to create tool form.
-        trans.get_history( create=True )
+        trans.get_history( most_recent=True, create=True )
 
         if id:
             # Loading a shared visualization.

templates/webapps/galaxy/workflow/display.mako

@@ -90,7 +90,7 @@
     <%
         # HACK: Rendering workflow steps requires that trans have a history; however, if its user's first visit to Galaxy is here, he won't have a history
         # and an error will occur. To prevent this error, make sure user has a history. 
-        trans.get_history( create=True ) 
+        trans.get_history( most_recent=True, create=True )
     %>
     <table class="annotated-item">
         <tr><th>Step</th><th class="annotation">Annotation</th></tr>