Updated tutorial to the flask script

docs/tutorial/dbinit.rst

@@ -20,28 +20,25 @@ require that we provide the path to the database  which can introduce
 errors.  It's a good idea to add a function that initializes the database
 for you to the application.
 
-To do this we can create a function called `init_db` that initializes the
-database.  Let me show you the code first.  Just add this function below
-the `connect_db` function in `flaskr.py`::
-
-    def init_db():
-        with app.app_context():
-            db = get_db()
-            with app.open_resource('schema.sql', mode='r') as f:
-                db.cursor().executescript(f.read())
-            db.commit()
-
-So what's happening here?  Remember how we learned last chapter that the
-application context is created every time a request comes in?  Here we
-don't have a request yet, so we need to create the application context by
-hand.  Without an application context the :data:`~flask.g` object does not
-know yet to which application it becomes as there could be more than one!
-
-The ``with app.app_context()`` statement establishes the application
-context for us.  In the body of the with statement the :data:`~flask.g`
-object will be associated with ``app``.  At the end of the with statement
-the association is released and all teardown functions are executed.  This
-means that our database connection is disconnected after the commit.
+To do this we can create a function and hook it into the ``flask`` command
+that initializes the database.  Let me show you the code first.  Just add
+this function below the `connect_db` function in `flaskr.py`::
+
+    @app.cli.command()
+    def initdb():
+        """Initializes the database."""
+        db = get_db()
+        with app.open_resource('schema.sql', mode='r') as f:
+            db.cursor().executescript(f.read())
+        db.commit()
+        print 'Initialized the database.'
+
+The ``app.cli.command()`` decorator registers a new command with the
+``flask`` script.  When the command executes Flask will automatically
+create a application context for us bound to the right application.
+Within the function we can then access :attr:`flask.g` and other things as
+we would expect.  When the script ends, the application context tears down
+and the database connection is released.
 
 The :func:`~flask.Flask.open_resource` method of the application object
 is a convenient helper function that will open a resource that the
@@ -54,16 +51,15 @@ On that cursor there is a method to execute a complete script.  Finally we
 only have to commit the changes.  SQLite 3 and other transactional
 databases will not commit unless you explicitly tell it to.
 
-Now it is possible to create a database by starting up a Python shell and
-importing and calling that function::
+Now it is possible to create a database with the ``flask`` script::
 
->>> from flaskr import init_db
->>> init_db()
+    flask --app=flaskr initdb
+    Initialized the database.
 
 .. admonition:: Troubleshooting
 
    If you get an exception later that a table cannot be found check that
-   you did call the `init_db` function and that your table names are
+   you did execute the `initdb` command and that your table names are
    correct (singular vs. plural for example).
 
 Continue with :ref:`tutorial-views`

docs/tutorial/setup.rst

@@ -29,7 +29,6 @@ config from the same file, in `flaskr.py`::
     # Load default config and override config from an environment variable
     app.config.update(dict(
         DATABASE=os.path.join(app.root_path, 'flaskr.db'),
-        DEBUG=True,
         SECRET_KEY='development key',
         USERNAME='admin',
         PASSWORD='default'
@@ -71,10 +70,7 @@ module.  Flask will the initialize the variable from that module.  Note
 that in all cases only variable names that are uppercase are considered.
 
 The ``SECRET_KEY`` is needed to keep the client-side sessions secure.
-Choose that key wisely and as hard to guess and complex as possible.  The
-debug flag enables or disables the interactive debugger.  *Never leave
-debug mode activated in a production system*, because it will allow users to
-execute code on the server!
+Choose that key wisely and as hard to guess and complex as possible.
 
 We will also add a method that allows for  easily connecting to the
 specified database.  This can be used to open a connection on request and
@@ -92,16 +88,14 @@ tuples.
         rv.row_factory = sqlite3.Row
         return rv
 
-Finally we just add a line to the bottom of the file that fires up the
-server if we want to run that file as a standalone application::
-
-    if __name__ == '__main__':
-        app.run()
-
 With that out of the way you should be able to start up the application
 without problems.  Do this with the following command::
 
-   python flaskr.py
+    flask --app=flaskr --debug run
+
+The ``--debug`` flag enables or disables the interactive debugger.  *Never
+leave debug mode activated in a production system*, because it will allow
+users to execute code on the server!
 
 You will see a message telling you that server has started along with
 the address at which you can access it.

examples/flaskr/.gitignore

@@ -0,0 +1 @@
+flaskr.db

examples/flaskr/flaskr.py

@@ -37,13 +37,14 @@ def connect_db():
     return rv
 
 
-def init_db():
+@app.cli.command()
+def initdb():
     """Creates the database tables."""
-    with app.app_context():
-        db = get_db()
-        with app.open_resource('schema.sql', mode='r') as f:
-            db.cursor().executescript(f.read())
-        db.commit()
+    db = get_db()
+    with app.open_resource('schema.sql', mode='r') as f:
+        db.cursor().executescript(f.read())
+    db.commit()
+    print('Initialized the database.')
 
 
 def get_db():
@@ -76,7 +77,7 @@ def add_entry():
         abort(401)
     db = get_db()
     db.execute('insert into entries (title, text) values (?, ?)',
-                 [request.form['title'], request.form['text']])
+               [request.form['title'], request.form['text']])
     db.commit()
     flash('New entry was successfully posted')
     return redirect(url_for('show_entries'))
@@ -102,8 +103,3 @@ def logout():
     session.pop('logged_in', None)
     flash('You were logged out')
     return redirect(url_for('show_entries'))
-
-
-if __name__ == '__main__':
-    init_db()
-    app.run()