Flask-Sieve

A requests validator for Flask inspired by Laravel.

This package provides an approach to validating incoming requests using powerful and composable rules.

Installing

To install and update using pip.

pip install -U flask-sieve

Quickstart

To learn about these powerful validation features, let's look at a complete example of validating a form and displaying the error messages back to the user.

Example App

Suppose you had a simple application with an endpoint to register a user. We are going to create validations for this endpoint.

# app.py

from flask import Flask

app = Flask(__name__)

@app.route('/', methods=('POST',))
def register():
    return 'Registered!'

app.run()

The Validation Logic

To validate incoming requests to this endpoint, we create a class with validation rules of registering a user as follows:

# app_requests.py

from flask_sieve import FormRequest

class RegisterRequest(FormRequest):
    def rules(self):
        return {
            'email': ['required', 'email'],
            'username': ['required', 'string', 'min:6'],
            'password': ['required', 'min:6', 'confirmed']
        }

Now, using this class, we can guard our endpoint using a validate decorator.

# app.py

from flask import Flask
from flask_sieve import Sieve, validate
from .app_requests import RegisterRequest

app = Flask(__name__)
Sieve(app)

@app.route('/', methods=('POST'))
@validate(RegisterRequest)
def register():
    return 'Registered!'

app.run()

If the validation fails, the proper response is automatically generated.

Documentation

Find the documentation here.

License (BSD-2)

A Flask package for validating requests (Inspired by Laravel).

Copyright © 2019 Edward Njoroge

All rights reserved.

Find a copy of the License here.