First part of the tutorial. Many explanations missing but it's a start.

examples/flaskr/flaskr.py

@@ -43,11 +43,8 @@ def init_db():
 
 @app.request_init
 def before_request():
-    """Make sure we are connected to the database each request.  Also
-    set `g.logged_in` to `True` if we are logged in.
-    """
+    """Make sure we are connected to the database each request."""
     g.db = connect_db()
-    g.logged_in = session.get('logged_in', False)
 
 
 @app.request_shutdown
@@ -66,7 +63,7 @@ def show_entries():
 
 @app.route('/add', methods=['POST'])
 def add_entry():
-    if not g.logged_in:
+    if not session.get('logged_in'):
         abort(401)
     g.db.execute('insert into entries (title, text) values (?, ?)',
                  [request.form['title'], request.form['text']])

examples/flaskr/static/style.css

@@ -3,14 +3,15 @@ a, h1, h2 { color: #377BA8; }
 h1, h2 { font-family: 'Georgia', serif; margin: 0; }
 h1 { border-bottom: 2px solid #eee; }
 h2 { font-size: 1.2em; }
-div.metanav { text-align: right; font-size: 0.8em; background: #fafafa;
-              padding: 0.3em; margin-bottom: 1em; }
+
+div.page { margin: 2em auto; width: 35em; border: 5px solid #ccc;
+           padding: 0.8em; background: white; }
 ul.entries { list-style: none; margin: 0; padding: 0; }
 ul.entries li { margin: 0.8em 1.2em; }
 ul.entries li h2 { margin-left: -1em; }
-div.page { margin: 2em auto; width: 35em; border: 5px solid #ccc;
-           padding: 0.8em; background: white; }
 form.add-entry { font-size: 0.9em; border-bottom: 1px solid #ccc; }
 form.add-entry dl { font-weight: bold; }
+div.metanav { text-align: right; font-size: 0.8em; background: #fafafa;
+              padding: 0.3em; margin-bottom: 1em; }
 div.flash { background: #CEE5F5; padding: 0.5em; border: 1px solid #AACBE2; }
 p.error { background: #F0D6D6; padding: 0.5em; }

examples/flaskr/templates/layout.html

@@ -4,7 +4,7 @@
 <div class=page>
   <h1>Flaskr</h1>
   <div class=metanav>
-  {% if not g.logged_in %}
+  {% if not session.logged_in %}
     <a href="{{ url_for('login') }}">log in</a>
   {% else %}
     <a href="{{ url_for('logout') }}">log out</a>

examples/flaskr/templates/login.html

@@ -7,7 +7,7 @@
       <dt>Username:
       <dd><input type=text name=username>
       <dt>Password:
-      <dd><input type=passowrd name=password>
+      <dd><input type=password name=password>
       <dd><input type=submit value=Login>
     </dl>
   </form>