Merge pull request #2228 from wgwz/improve-flaskr

Add blueprint and the app factory pattern into the flaskr example

examples/flaskr/README

@@ -9,9 +9,11 @@
 
     ~ How do I use it?
 
-      1. edit the configuration in the flaskr.py file or
+      1. edit the configuration in the factory.py file or
          export an FLASKR_SETTINGS environment variable
-         pointing to a configuration file.
+         pointing to a configuration file or pass in a 
+         dictionary with config values using the create_app
+         function.
 
       2. install the app from the root of the project directory
 
@@ -19,7 +21,7 @@
 
       3. Instruct flask to use the right application
 
-         export FLASK_APP=flaskr
+         export FLASK_APP=flaskr._cliapp
 
       4. initialize the database with this command:
 

examples/flaskr/flaskr/__init__.py

@@ -1 +0,0 @@
-from .flaskr import app

examples/flaskr/flaskr/_cliapp.py

@@ -0,0 +1,15 @@
+# -*- coding: utf-8 -*-
+"""
+    Flaskr
+    ~~~~~~
+
+    A microblog example application written as Flask tutorial with
+    Flask and sqlite3.
+
+    :copyright: (c) 2015 by Armin Ronacher.
+    :license: BSD, see LICENSE for more details.
+"""
+
+from flaskr.factory import create_app
+
+app = create_app()

examples/flaskr/flaskr/blueprints/flaskr.py

@@ -10,29 +10,18 @@
     :license: BSD, see LICENSE for more details.
 """
 
-import os
 from sqlite3 import dbapi2 as sqlite3
-from flask import Flask, request, session, g, redirect, url_for, abort, \
-     render_template, flash
+from flask import Blueprint, request, session, g, redirect, url_for, abort, \
+     render_template, flash, current_app
 
 
-# create our little application :)
-app = Flask(__name__)
-
-# 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'
-))
-app.config.from_envvar('FLASKR_SETTINGS', silent=True)
+# create our blueprint :)
+bp = Blueprint('flaskr', __name__)
 
 
 def connect_db():
     """Connects to the specific database."""
-    rv = sqlite3.connect(app.config['DATABASE'])
+    rv = sqlite3.connect(current_app.config['DATABASE'])
     rv.row_factory = sqlite3.Row
     return rv
 
@@ -40,18 +29,11 @@ def connect_db():
 def init_db():
     """Initializes the database."""
     db = get_db()
-    with app.open_resource('schema.sql', mode='r') as f:
+    with current_app.open_resource('schema.sql', mode='r') as f:
         db.cursor().executescript(f.read())
     db.commit()
 
 
-@app.cli.command('initdb')
-def initdb_command():
-    """Creates the database tables."""
-    init_db()
-    print('Initialized the database.')
-
-
 def get_db():
     """Opens a new database connection if there is none yet for the
     current application context.
@@ -61,14 +43,7 @@ def get_db():
     return g.sqlite_db
 
 
-@app.teardown_appcontext
-def close_db(error):
-    """Closes the database again at the end of the request."""
-    if hasattr(g, 'sqlite_db'):
-        g.sqlite_db.close()
-
-
-@app.route('/')
+@bp.route('/')
 def show_entries():
     db = get_db()
     cur = db.execute('select title, text from entries order by id desc')
@@ -76,7 +51,7 @@ def show_entries():
     return render_template('show_entries.html', entries=entries)
 
 
-@app.route('/add', methods=['POST'])
+@bp.route('/add', methods=['POST'])
 def add_entry():
     if not session.get('logged_in'):
         abort(401)
@@ -85,26 +60,26 @@ def add_entry():
                [request.form['title'], request.form['text']])
     db.commit()
     flash('New entry was successfully posted')
-    return redirect(url_for('show_entries'))
+    return redirect(url_for('flaskr.show_entries'))
 
 
-@app.route('/login', methods=['GET', 'POST'])
+@bp.route('/login', methods=['GET', 'POST'])
 def login():
     error = None
     if request.method == 'POST':
-        if request.form['username'] != app.config['USERNAME']:
+        if request.form['username'] != current_app.config['USERNAME']:
             error = 'Invalid username'
-        elif request.form['password'] != app.config['PASSWORD']:
+        elif request.form['password'] != current_app.config['PASSWORD']:
             error = 'Invalid password'
         else:
             session['logged_in'] = True
             flash('You were logged in')
-            return redirect(url_for('show_entries'))
+            return redirect(url_for('flaskr.show_entries'))
     return render_template('login.html', error=error)
 
 
-@app.route('/logout')
+@bp.route('/logout')
 def logout():
     session.pop('logged_in', None)
     flash('You were logged out')
-    return redirect(url_for('show_entries'))
+    return redirect(url_for('flaskr.show_entries'))

examples/flaskr/flaskr/factory.py

@@ -0,0 +1,64 @@
+# -*- coding: utf-8 -*-
+"""
+    Flaskr
+    ~~~~~~
+
+    A microblog example application written as Flask tutorial with
+    Flask and sqlite3.
+
+    :copyright: (c) 2015 by Armin Ronacher.
+    :license: BSD, see LICENSE for more details.
+"""
+
+import os
+from flask import Flask, g
+from werkzeug.utils import find_modules, import_string
+from flaskr.blueprints.flaskr import init_db
+
+
+def create_app(config=None):
+    app = Flask(__name__)
+
+    app.config.update(dict(
+        DATABASE=os.path.join(app.root_path, 'flaskr.db'),
+        DEBUG=True,
+        SECRET_KEY='development key',
+        USERNAME='admin',
+        PASSWORD='default'
+    ))
+    app.config.update(config or {})
+    app.config.from_envvar('FLASKR_SETTINGS', silent=True)
+
+    register_blueprints(app)
+    register_cli(app)
+    register_teardowns(app)
+
+    return app
+
+
+def register_blueprints(app):
+    """Register all blueprint modules
+
+    Reference: Armin Ronacher, "Flask for Fun and for Profit" PyBay 2016.
+    """
+    for name in find_modules('flaskr.blueprints'):
+        mod = import_string(name)
+        if hasattr(mod, 'bp'):
+            app.register_blueprint(mod.bp)
+    return None
+
+
+def register_cli(app):
+    @app.cli.command('initdb')
+    def initdb_command():
+        """Creates the database tables."""
+        init_db()
+        print('Initialized the database.')
+
+
+def register_teardowns(app):
+    @app.teardown_appcontext
+    def close_db(error):
+        """Closes the database again at the end of the request."""
+        if hasattr(g, 'sqlite_db'):
+            g.sqlite_db.close()

examples/flaskr/flaskr/templates/layout.html

@@ -5,9 +5,9 @@
   <h1>Flaskr</h1>
   <div class="metanav">
   {% if not session.logged_in %}
-    <a href="{{ url_for('login') }}">log in</a>
+    <a href="{{ url_for('flaskr.login') }}">log in</a>
   {% else %}
-    <a href="{{ url_for('logout') }}">log out</a>
+    <a href="{{ url_for('flaskr.logout') }}">log out</a>
   {% endif %}
   </div>
   {% for message in get_flashed_messages() %}

examples/flaskr/flaskr/templates/login.html

@@ -2,7 +2,7 @@
 {% block body %}
   <h2>Login</h2>
   {% if error %}<p class="error"><strong>Error:</strong> {{ error }}{% endif %}
-  <form action="{{ url_for('login') }}" method="post">
+  <form action="{{ url_for('flaskr.login') }}" method="post">
     <dl>
       <dt>Username:
       <dd><input type="text" name="username">

examples/flaskr/flaskr/templates/show_entries.html

@@ -1,7 +1,7 @@
 {% extends "layout.html" %}
 {% block body %}
   {% if session.logged_in %}
-    <form action="{{ url_for('add_entry') }}" method="post" class="add-entry">
+    <form action="{{ url_for('flaskr.add_entry') }}" method="post" class="add-entry">
       <dl>
         <dt>Title:
         <dd><input type="text" size="30" name="title">

examples/flaskr/setup.cfg

@@ -1,2 +1,2 @@
-[tool:pytest]
-test=pytest
+[aliases]
+test=pytest

examples/flaskr/setup.py

@@ -1,8 +1,19 @@
-from setuptools import setup
+# -*- coding: utf-8 -*-
+"""
+    Flaskr Tests
+    ~~~~~~~~~~~~
+
+    Tests the Flaskr application.
+
+    :copyright: (c) 2015 by Armin Ronacher.
+    :license: BSD, see LICENSE for more details.
+"""
+
+from setuptools import setup, find_packages
 
 setup(
     name='flaskr',
-    packages=['flaskr'],
+    packages=find_packages(),
     include_package_data=True,
     install_requires=[
         'flask',

examples/flaskr/tests/test_flaskr.py

@@ -12,19 +12,38 @@
 import os
 import tempfile
 import pytest
-from flaskr import flaskr
+from flaskr.factory import create_app
+from flaskr.blueprints.flaskr import init_db
 
 
 @pytest.fixture
-def client():
-    db_fd, flaskr.app.config['DATABASE'] = tempfile.mkstemp()
-    flaskr.app.config['TESTING'] = True
-    client = flaskr.app.test_client()
-    with flaskr.app.app_context():
-        flaskr.init_db()
-    yield client
-    os.close(db_fd)
-    os.unlink(flaskr.app.config['DATABASE'])
+def app(request):
+
+    db_fd, temp_db_location = tempfile.mkstemp()
+    config = {
+        'DATABASE': temp_db_location,
+        'TESTING': True,
+        'DB_FD': db_fd
+    }
+
+    app = create_app(config=config)
+
+    with app.app_context():
+        init_db()
+        yield app
+
+
+@pytest.fixture
+def client(request, app):
+
+    client = app.test_client()
+
+    def teardown():
+        os.close(app.config['DB_FD'])
+        os.unlink(app.config['DATABASE'])
+    request.addfinalizer(teardown)
+
+    return client
 
 
 def login(client, username, password):
@@ -44,25 +63,25 @@ def test_empty_db(client):
     assert b'No entries here so far' in rv.data
 
 
-def test_login_logout(client):
+def test_login_logout(client, app):
     """Make sure login and logout works"""
-    rv = login(client, flaskr.app.config['USERNAME'],
-               flaskr.app.config['PASSWORD'])
+    rv = login(client, app.config['USERNAME'],
+               app.config['PASSWORD'])
     assert b'You were logged in' in rv.data
     rv = logout(client)
     assert b'You were logged out' in rv.data
-    rv = login(client, flaskr.app.config['USERNAME'] + 'x',
-               flaskr.app.config['PASSWORD'])
+    rv = login(client,app.config['USERNAME'] + 'x',
+               app.config['PASSWORD'])
     assert b'Invalid username' in rv.data
-    rv = login(client, flaskr.app.config['USERNAME'],
-               flaskr.app.config['PASSWORD'] + 'x')
+    rv = login(client, app.config['USERNAME'],
+               app.config['PASSWORD'] + 'x')
     assert b'Invalid password' in rv.data
 
 
-def test_messages(client):
+def test_messages(client, app):
     """Test that messages work"""
-    login(client, flaskr.app.config['USERNAME'],
-          flaskr.app.config['PASSWORD'])
+    login(client, app.config['USERNAME'],
+          app.config['PASSWORD'])
     rv = client.post('/add', data=dict(
         title='<Hello>',
         text='<strong>HTML</strong> allowed here'