Switch to flask-sqlalchemy to dispose of connections properly

pybossa/core.py

@@ -18,6 +18,7 @@
 from flask import Flask
 from flaskext.login import LoginManager, current_user
 from flaskext.gravatar import Gravatar
+from flask.ext.sqlalchemy import SQLAlchemy
 
 from pybossa import default_settings as settings
 
@@ -71,4 +72,5 @@ def setup_logging(app):
 login_manager.login_view = "/account/signin"
 login_manager.login_message = u"Please sign in to access this page."
 app = create_app()
+db = SQLAlchemy(app)
 

pybossa/model.py

@@ -23,39 +23,31 @@
 
 from werkzeug import generate_password_hash, check_password_hash
 import flaskext.login
-from sqlalchemy import create_engine
 from sqlalchemy import BigInteger, Integer, Boolean, Unicode,\
         Float, UnicodeText, Text, String
 from sqlalchemy.schema import Table, MetaData, Column, ForeignKey
 from sqlalchemy.orm import relationship, backref, class_mapper
-from sqlalchemy.ext.declarative import declarative_base
-from sqlalchemy.orm import scoped_session, sessionmaker
 from sqlalchemy.types import MutableType, TypeDecorator
 from sqlalchemy import event
 
+from pybossa.core import db
 from pybossa.util import pretty_date
 
 log = logging.getLogger(__name__)
 
-Session = scoped_session(sessionmaker())
-
-
-def set_engine(engine):
-    Base.metadata.bind = engine
-
+Session = db.session
 
 def make_timestamp():
     now = datetime.datetime.now()
     return now.isoformat()
 
-
 def make_uuid():
     return str(uuid.uuid4())
 
 
 def rebuild_db():
-    Base.metadata.drop_all()
-    Base.metadata.create_all()
+    db.drop_all()
+    db.create_all()
 
 # =========================================
 # Basics
@@ -98,6 +90,7 @@ class StateEnum:
 
 
 class DomainObject(object):
+
     def dictize(self):
         out = {}
         for col in self.__table__.c:
@@ -124,13 +117,10 @@ def __unicode__(self):
         return repr
 
 
-Base = declarative_base(cls=DomainObject)
-
-
 # =========================================
 # Domain Objects
 
-class App(Base):
+class App(db.Model, DomainObject):
     '''A microtasking Application to which Tasks are associated.
     '''
     __tablename__ = 'app'
@@ -201,7 +191,7 @@ def last_activity(self):
             return "None"
 
 
-class Featured(Base):
+class Featured(db.Model, DomainObject):
     '''A Table with Featured Apps.
     '''
     __tablename__ = 'featured'
@@ -213,7 +203,7 @@ class Featured(Base):
     app_id = Column(Integer, ForeignKey('app.id'))
 
 
-class Task(Base):
+class Task(db.Model, DomainObject):
     '''An individual Task which can be performed by a user. A Task is
     associated to an App.
     '''
@@ -263,7 +253,7 @@ def pct_status(self):
             return float(0)
 
 
-class TaskRun(Base):
+class TaskRun(db.Model, DomainObject):
     '''A run of a given task by a specific user.
     '''
     __tablename__ = 'task_run'
@@ -296,7 +286,7 @@ class TaskRun(Base):
     '''
 
 
-class User(Base, flaskext.login.UserMixin):
+class User(db.Model, DomainObject, flaskext.login.UserMixin):
     __tablename__ = 'user'
     id = Column(Integer, primary_key=True)
     #: created timestamp (automatically set)
@@ -350,3 +340,4 @@ def make_admin(mapper, conn, target):
     if users == 0:
         target.admin = True
         #print "User %s is the first one, so we make it an admin" % target.name
+

pybossa/web.py

@@ -68,19 +68,6 @@ def url_for_other_page(page):
     return url_for(request.endpoint, **args)
 app.jinja_env.globals['url_for_other_page'] = url_for_other_page
 
-@app.before_request
-def bind_db_engine():
-    dburi = app.config.get('SQLALCHEMY_DATABASE_URI', '')
-    if dburi:
-        engine = model.create_engine(dburi)
-        model.set_engine(engine)
-    else:
-        flash('You have not yet configured the database', 'error')
-
-@app.teardown_request
-def teardown_request(exception):
-    model.Session.close()
-
 #@app.errorhandler(401)
 #@app.errorhandler(403)
 #@app.errorhandler(404)
@@ -116,11 +103,6 @@ def global_template_context():
 
 @login_manager.user_loader
 def load_user(username):
-    # HACK: this repetition is painful but seems that before_request not yet called
-    # TODO: maybe time to use Flask-SQLAlchemy
-    dburi = app.config.get('SQLALCHEMY_DATABASE_URI', '')
-    engine = model.create_engine(dburi)
-    model.set_engine(engine)
     return model.Session.query(model.User).filter_by(name=username).first()
 
 @app.before_request
@@ -131,9 +113,6 @@ def api_authentication():
     if 'Authorization' in request.headers:
         apikey = request.headers.get('Authorization')
     if apikey:
-        dburi = app.config.get('SQLALCHEMY_DATABASE_URI', '')
-        engine = model.create_engine(dburi)
-        model.set_engine(engine)
         user = model.Session.query(model.User).filter_by(api_key=apikey).first()
         ## HACK: 
         # login_user sets a session cookie which we really don't want.

requirements.txt

@@ -4,6 +4,7 @@ Flask-Login==0.1
 Flask-WTF==0.6
 Flask-Gravatar
 Flask-OAuth
+Flask-SQLAlchemy
 dateutils
 alembic
 psycopg2

test/base.py

@@ -7,8 +7,8 @@
 _here = os.path.dirname(__file__)
 web.app.config['TESTING'] = True
 web.app.config['SQLALCHEMY_DATABASE_URI'] = web.app.config['SQLALCHEMY_DATABASE_TEST_URI']
-engine = model.create_engine(web.app.config['SQLALCHEMY_DATABASE_URI'])
-model.set_engine(engine)
+#engine = model.create_engine(web.app.config['SQLALCHEMY_DATABASE_URI'])
+#model.set_engine(engine)
 
 class Fixtures:
     fullname = u'T Tester'