Flask-Hashids

Hashids integration for Flask applications, it is based on the Hashid package available on PyPi. With this extension you can conveniently use integer ids for your application logic or database tables and hash them before exposing it in URLs or JSON data.

Installation

The latest stable version is available on PyPI. Either add Flask-Hashids to your requirements.txt file or install with pip:

pip install Flask-Hashids

Configuration

Flask-Hashids is configured through the standard Flask config API. These are the available options:

• HASHIDS_ALPHABET: Read more about that in Hashids documentation
• HASHIDS_MIN_LENGTH: Read more about that in Hashids documentation
• HASHIDS_SALT: It is strongly recommended that this is NEVER the same as the SECRET_KEY. Read more about this option in Hashids documentation

Examples

You can find more detailed examples on how to use Flask-Hashids in the examples directory.

from flask import Flask, jsonify, url_for
from flask_hashids import HashidMixin, Hashids
from flask_sqlalchemy import SQLAlchemy


app = Flask(__name__)
app.config['SECRET_KEY'] = 'top_secret_key'
app.config['HASHIDS_SALT'] = 'secret!'
app.config['SQLALCHEMY_DATABASE_URI'] = 'sqlite://'
db = SQLAlchemy(app)
hashids = Hashids(app)


# The HashidMixin class adds the hashid property which will compute a hashid
# based on the existing id attribute of the instance.
# NOTE: The id attribute must be an int
class User(HashidMixin, db.Model):
    __tablename__ = 'users'

    id = db.Column(db.Integer, primary_key=True)
    name = db.Column(db.String(64), nullable=False)

    @property
    def url(self):
        # The HashidConverter encodes the given id to a hashid in the URL
        return url_for('user', user_id=self.id)

    def to_json_serializeable(self):
        return {'id': self.hashid, 'name': self.name, 'url': self.url}


@app.before_first_request
def database_setup():
    db.create_all()
    john = User(name='John')
    db.session.add(john)
    jane = User(name='Jane')
    db.session.add(jane)
    db.session.commit()


@app.route('/users')
def users():
    return [user.to_json_serializeable() for user in User.query.all()], 200


@app.route('/users/<hashid:user_id>')
def user(user_id: int):
    # The HashidConverter decodes the given hashid to an int
    user = User.query.get(user_id)
    if user is None:
        return jsonify('User not found'), 404
    return user.to_json_serializeable(), 200


def main():
    # You can encode and decode hashids manually
    id = 123
    encoded_id = hashids.encode(id)
    decoded_id = hashids.decode(encoded_id)
    app.run()


if __name__ == '__main__':
    main()

Resources

• https://hashids.org/python/