librelist archives

Proper usage of flask blueprints with flask-SQLAlchemy

From:

VDziubak

Date:

2012-01-27 @ 08:39

Hello!
I am new to flask, but i liked it and i have encountered the next problem:
I liked the concept of blueprints and also want to use flask-SQLAlchemy 
to add some database-functionality to the site. But what is the best way 
to do that?
For now have written something like this (and, surprisingly, it works! =) )

my folder structure:

     templates/
     static/
     static_page/
         __init__.py
         models.py
         views.py

     config.py
     runserver.py
     test.db

files:

/*#config.py*
/from os import path
DATABASE = 'flaskr.db'
DEBUG = True
SECRET_KEY = 'key'
SQLALCHEMY_DATABASE_URI = 'sqlite:///%s/test.db' % 
path.dirname(path.abspath(__file__))

*/#runserver.py/*
from flask import Flask
from flaskext.sqlalchemy import SQLAlchemy

app = Flask(__name__)
app.config.from_pyfile('config.py')
db = SQLAlchemy(app)

/# import blueprints/
from static_page.views import page

app.register_blueprint(page)

@app.template_filter('datetimeformat')
def datetimeformat(value, format='%H:%M / %d-%m-%Y'):
   return value.strftime(format)

if __name__ == '__main__':
   app.run()


*/#static_page/views.py/*
from flask import Blueprint, render_template

page = Blueprint('page', __name__)

from static_page.models import Article

@page.route('/', defaults={'alias':'index'})
@page.route('/<alias>/')
def show_page(alias):
   article = Article.query.filter_by(alias = alias).first_or_404()
   return render_template("page.html", article=article)

*/#static_page/models.py
/*from datetime import datetime
from runserver import db

class Article(db.Model):
   __tablename__ = 'articles'
   id = db.Column(db.Integer, primary_key = True)
   title = db.Column(db.String(20), unique = True)
   text = db.Column(db.Text)
   mod_date = db.Column(db.DateTime)
   alias = db.Column(db.String(20), unique = True)

   def __init__(self, title, text, alias):
     self.mod_date = datetime.utcnow()
     self.title = title
     self.text = text;
     self.alias = alias;

   def __repr__(self):
     return "<%s at %s>" % (self.title, self.alias)

*static_page/__init__.py*   is empt/y
/
But i think that there must be something better than this. In one of the 
topics I have seen next:

It's better to also couple that with blueprints, then you don't have to
create the views in a function:

     db = SQLAlchemy()
     frontend = Blueprint('frontend', __name__)

     @frontend.route('/')
     def index():
         ...

     def create_app(config):
         app = Flask(__name__)
         app.config.update(config)
         app.register_blueprint(frontend)
         db.init_app(app)
         return app

Could somebody, please, explain me where should i put this last 
create_app function and how (and where) should I use it?

Sorry for grammar (and, perhaps, spelling) errors,
best regards,
V.Dzyubak