Rewrote tutorial to use the g based appcontext object

examples/flaskr/flaskr.py

@@ -11,22 +11,31 @@
 """
 
 from sqlite3 import dbapi2 as sqlite3
-from flask import Flask, request, session, redirect, url_for, abort, \
-     render_template, flash, _app_ctx_stack
+from flask import Flask, request, session, g, redirect, url_for, abort, \
+     render_template, flash
 
-# configuration
-DATABASE = '/tmp/flaskr.db'
-DEBUG = True
-SECRET_KEY = 'development key'
-USERNAME = 'admin'
-PASSWORD = 'default'
 
 # create our little application :)
 app = Flask(__name__)
-app.config.from_object(__name__)
+
+# Load default config and override config from an environment variable
+app.config.update(dict(
+    DATABASE='/tmp/flaskr.db',
+    DEBUG=True,
+    SECRET_KEY='development key',
+    USERNAME='admin',
+    PASSWORD='default'
+))
 app.config.from_envvar('FLASKR_SETTINGS', silent=True)
 
 
+def connect_db():
+    """Connects to the specific database."""
+    rv = sqlite3.connect(app.config['DATABASE'])
+    rv.row_factory = sqlite3.Row
+    return rv
+
+
 def init_db():
     """Creates the database tables."""
     with app.app_context():
@@ -40,21 +49,16 @@ def get_db():
     """Opens a new database connection if there is none yet for the
     current application context.
     """
-    top = _app_ctx_stack.top
-    if not hasattr(top, 'sqlite_db'):
-        sqlite_db = sqlite3.connect(app.config['DATABASE'])
-        sqlite_db.row_factory = sqlite3.Row
-        top.sqlite_db = sqlite_db
-
-    return top.sqlite_db
+    if not hasattr(g, 'sqlite_db'):
+        g.sqlite_db = connect_db()
+    return g.sqlite_db
 
 
 @app.teardown_appcontext
-def close_db_connection(exception):
+def close_db(error):
     """Closes the database again at the end of the request."""
-    top = _app_ctx_stack.top
-    if hasattr(top, 'sqlite_db'):
-        top.sqlite_db.close()
+    if hasattr(g, 'sqlite_db'):
+        g.sqlite_db.close()
 
 
 @app.route('/')