[TASK] Make PersonMapper instance a module based singleton.

frontend/models.py

@@ -23,9 +23,8 @@ class PersonGlobalIdentity(models.Model):
     # TODO: Extend this for further stuff - maybe vivo external  url or something?
 
     def __unicode__(self):
-        from service.Mapper import PersonMapper
-        pm = PersonMapper()
-        return u"<PersonGlobalIdentity repr='" + pm.get_representation_for_global_identity(self) + u"', ID=" + unicode(self.id) + u", type=" + unicode(self.type) + u">"
+        from service.Mapper import person_mapper
+        return u"<PersonGlobalIdentity repr='" + person_mapper.get_representation_for_global_identity(self) + u"', ID=" + unicode(self.id) + u", type=" + unicode(self.type) + u">"
 
 
 class CitaviProjectIdentity(models.Model):

frontend/views.py

@@ -19,6 +19,9 @@ from frontend.models import Project
 
 FRONTEND_PAGE_NAME = u'Citavi Mapper'
 
+from service.Mapper import person_mapper
+
+
 # Login wrapper functions
 def login_wrap(*args, **kwargs):
     """ Wrapper function for login page. """
@@ -187,11 +190,8 @@ class ProjectPersonView(ProtectedFormView, SingleObjectMixin):
     def get_context_data(self, **kwargs):
         project = self.object
 
-        from service import Mapper
-        pm = Mapper.PersonMapper()
-        kwargs[u'unmapped_persons'] = pm.get_unmapped_identities(project)
-        kwargs[u'mapped_persons'] = pm.get_mapped_identities_with_representation(project)
-        kwargs[u'mapped_persons'] = pm.get_mapped_identities_with_representation(project)
+        kwargs[u'unmapped_persons'] = person_mapper.get_unmapped_identities(project)
+        kwargs[u'mapped_persons'] = person_mapper.get_mapped_identities_with_representation(project)
         return super(ProjectPersonView, self).get_context_data(**kwargs)
 
     def get(self, request, *args, **kwargs):
@@ -218,9 +218,7 @@ class ProjectMapPersonView(ProtectedFormView, SingleObjectMixin):
     def get_context_data(self, **kwargs):
         project = self.object
 
-        from service import Mapper
-        pm = Mapper.PersonMapper()
-        kwargs[u'person'] = pm.get_person_by_uuid(project, self.person_uuid)
+        kwargs[u'person'] = person_mapper.get_person_by_uuid(project, self.person_uuid)
         return super(ProjectMapPersonView, self).get_context_data(**kwargs)
 
     def get(self, request, *args, **kwargs):
@@ -237,9 +235,7 @@ class ProjectMapPersonView(ProtectedFormView, SingleObjectMixin):
         return super(ProjectMapPersonView, self).post(request, *args, **kwargs)
 
     def form_valid(self, form, *args, **kwargs):
-        from service import Mapper
-        pm = Mapper.PersonMapper()
-        person = pm.get_person_by_uuid(self.object, self.person_uuid)
+        person = person_mapper.get_person_by_uuid(self.object, self.person_uuid)
 
         if form.data.get(u'skip', False):
             """ Nothing to do here, just go on ... """
@@ -247,10 +243,10 @@ class ProjectMapPersonView(ProtectedFormView, SingleObjectMixin):
         elif form.data.get(u'save-continue', False):
             # TODO: do mapping according to parameters, override success_url to point to next person!
             if form.cleaned_data[u'action'] == u'new':
-                pm.create_new_identity(self.object, person)
+                person_mapper.create_new_identity(self.object, person)
             elif form.cleaned_data[u'action'] == u'existing':
                 # TODO preferred = FALSE is not desired.
                 print form.cleaned_data
-                pm.map_identity_to_existing(form.cleaned_data[u'global_identity'], self.object, person.ID, form.cleaned_data[u'preferred_identity'])
+                person_mapper.map_identity_to_existing(form.cleaned_data[u'global_identity'], self.object, person.ID, form.cleaned_data[u'preferred_identity'])
         return super(ProjectMapPersonView, self).form_valid(form)
 

service/Citavi.py

@@ -2,7 +2,7 @@
 
 from sqlalchemy import create_engine, MetaData
 from sqlalchemy.ext.automap import automap_base
-from sqlalchemy.orm import Session
+from sqlalchemy.orm import Session, scoped_session, sessionmaker
 
 
 class Project():
@@ -28,7 +28,8 @@ class Project():
             person_class = self._sa_sqlite_autobase.classes.Person
             citavi_persons = self._sa_sqlite_session.query(person_class).all()
             return citavi_persons
-        except:
+        except Exception, e:
+            print e
             self._is_error = True
             # TODO: better error handling!
             print str(u"An error occured within a get_persons call!")
@@ -40,7 +41,8 @@ class Project():
             person_class = self._sa_sqlite_autobase.classes.Person
             citavi_person = self._sa_sqlite_session.query(person_class).filter(u'ID=\'' + unicode(uuid) + u'\'').all()
             return citavi_person[0]
-        except:
+        except Exception, e:
+            print e
             self._is_error = True
             # TODO: better error handling!
             print str(u"An error occured within a get_person_by_uuid call!")
@@ -60,7 +62,7 @@ class Project():
         """ Internal method to open a citavi project file. """
         try:
             self._sa_sqlite_engine = create_engine(u'sqlite+pysqlite:///' + self.sqlite_file)
-            self._sa_sqlite_session = Session(self._sa_sqlite_engine)
+            self._sa_sqlite_session = scoped_session(sessionmaker(bind=self._sa_sqlite_engine))  # Caution: SQLAlchemy Sessions are per thread!
             self._sa_sqlite_meta = MetaData(bind=self._sa_sqlite_engine)
             self._sa_sqlite_meta.reflect()
             self._sa_sqlite_autobase = automap_base()

service/Mapper.py

@@ -79,3 +79,4 @@ class PersonMapper():
         return unicode(citavi_person.ID) + u" " + unicode(citavi_person.FirstName) + u" " + unicode(citavi_person.LastName)
 
 
+person_mapper = PersonMapper()