Hi Community

In this article, I will introduce my application IRIS-FlaskBlog.

IRIS-FlaskBlog Application is a real-world application that leverages the functionality of Flask web framework, SQLALchemy ORM, and InterSystems IRIS. The application contains user registration and authentication with the help of Flask-Login python library, a responsive user interface to create and edit posts.

Application Features

User registration and authentication
Creation of a data structure with SQLALcemy model classes
Responsive user interface to create, edit, and delete posts
Like and add comments to the post
Search based on the user and based on the tags

Used Technologies

Flask: A micro web framework for Python that allows you to build web applications quickly and efficiently.Conduit
SQLAlchemy: An Object-Relational Mapping (ORM) library that provides a high-level, Pythonic interface for interacting with databases.
InterSystems IRIS: A high-performance, data platform that combines a powerful database with integration, analytics, and AI capabilities.

Installation

Clone/git pull the repo into any local directory

git clone https://github.com/mwaseem75/IRIS-FlaskBlog.git

Open a Docker terminal in this directory and run:

docker-compose build

Run the IRIS container:

docker-compose up -d

Application Flow

In the docker, ENTRYPOINT [ "python", "app.py" ] is defined which will initiate the application (The ENTRYPOINT instruction is used to configure the executables that will always run after the container is initiated)

# app.py
# import create_app from website package
from website import create_app
# import configuration parameters
from website.myconfig import *

if __name__ == "__main__":
    # Get db parameters and creating to create_app in order to create DB
    database_uri = f'iris://{DB_USER}:{DB_PASS}@{DB_URL}:{DB_PORT}/{DB_NAMESPACE}'
    app = create_app(database_uri)
    app.run('0.0.0.0', port="4040", debug=False)

The above code invokes create_app() function and then runs the application on port 4040

create_app() function is defined in \__init__.py file

from flask import Flask
from flask_sqlalchemy import SQLAlchemy
from flask_login import LoginManager
from .myconfig import *

db = SQLAlchemy()

def create_app(database_uri):
    #Import flask application
    app = Flask(__name__)
    app.config['SECRET_KEY'] = "iris-FlaskBlogKey"
    # assigning db parameters
    app.config['SQLALCHEMY_DATABASE_URI'] = database_uri
    #create and push an application context onto the application context stack
    app.app_context().push()

    from .views import views
    from .auth import auth
    from .models import User
    app.register_blueprint(views, url_prefix="/")
    app.register_blueprint(auth, url_prefix="/")

    db.init_app(app)

    with app.app_context():
        #Create database
        db.create_all()

    # Assign Login View
    login_manager = LoginManager()
    login_manager.login_view = "auth.login"
    login_manager.init_app(app)
    
    @login_manager.user_loader
    def load_user(id):
        return User.query.get(int(id))

    return app

The above code creates the database by invoking SQLAlchemy create_all() function which will create the database structure defined in the models.py file

from . import db
from flask_login import UserMixin
from sqlalchemy.sql import func

#creates tags_accosication table
tags_table = db.Table(
    'tags_association',
    db.Column('post_id', db.ForeignKey('post.id'), primary_key=True),
    db.Column('tag_id', db.ForeignKey('tag.id'), primary_key=True),
)

#Users table
class User(db.Model, UserMixin):
    id = db.Column(db.Integer, primary_key=True)
    email = db.Column(db.String(150), unique=True)
    username = db.Column(db.String(150), unique=True)
    password = db.Column(db.String(150))
    date_created = db.Column(db.DateTime(timezone=True), default=func.now())
    posts = db.relationship('Post', backref='user', passive_deletes=True)
    comments = db.relationship('Comment', backref='user', passive_deletes=True)
    likes = db.relationship('Like', backref='user', passive_deletes=True)

def __repr__(self):
        return f'{self.username}'
#Posts Table
class Post(db.Model):
    id = db.Column(db.Integer, primary_key=True)
    title = db.Column(db.String(250))
    content = db.Column(db.Text)
    date_created = db.Column(db.DateTime(timezone=True), default=func.now())
    author = db.Column(db.Integer, db.ForeignKey(
        'user.id', ondelete="CASCADE"), nullable=False)
    comments = db.relationship('Comment', backref='post', passive_deletes=True)
    likes = db.relationship('Like', backref='post', passive_deletes=True)
    tags = db.relationship('Tag', secondary=tags_table,
                           backref=db.backref('posts', lazy='dynamic'))


    def __repr__(self):
        user = User.query.filter_by(id=self.author).first()
        return f'{user.username}'
#Tags table
class Tag(db.Model):
    id = db.Column(db.Integer, primary_key=True)
    name = db.Column(db.String(150))

    def __repr__(self):
        return f'{self.name}'
#Comments table
class Comment(db.Model)&:
    id = db.Column(db.Integer, primary_key=True)
    text = db.Column(db.String(500), nullable=False)
    date_created = db.Column(db.DateTime(timezone=True), default=func.now())
    author = db.Column(db.Integer, db.ForeignKey(
        'user.id'&, ondelete=&"CASCADE"), nullable=False)
    post_id = db.Column(db.Integer, db.ForeignKey(
        'post.id', ondelete="CASCADE"), nullable=False)

#Like table
class Like(db.Model):
    id = db.Column(db.Integer, primary_key=True&)
    date_created = db.Column(db.DateTime(timezone=True), default=func.now())
    author = db.Column(db.Integer, db.ForeignKey(
        'user.id', ondelete="CASCADE"), nullable=False&)
    post_id = db.Column(db.Integer, db.ForeignKey(
        'post.id', ondelete="CASCADE"), nullable=False)

Application Database

SQLALchemy will create below tables:

user: To store User information
post: To store Posts related data
tags: To store Tags against the post
tags_association: To store links between Posts and Tags
comments: To save post comments by users
like: To store likes details by users

To view table details, navigate to http://localhost:52775/csp/sys/exp/%25CSP.UI.Portal.SQL.Home.zen?$NAMESPACE=USER#

For more details please visit IRIS-FlaskBlog application page

Thanks

InterSystems IRIS Flask Blog application

Application Features

Application Database