Gigaspoon - A library for handling Flask forms.

This is a super simple library I wrote to help handle validating Flask forms. It's currently very unstable so I wouldn't recommend using it as things can and probably will change over time.

This framework is designed to assist with validating input, while also offering options to help with creating forms. Unlike other frameworks, the priority is towards validation, leaving the creation and design of forms to the developer.

Why?

I like to think WTForms is appropriately named, because every time I hear someone speaking about it, I always hear one thing - "WTF???". It feels like a complicated library for something that should be super simple, and I hope that with Gigaspoon, I'm able to make it as simple as possible for people to validate their forms. In the future, there might also be some helpful utilities set in flask.g to help with autogenerating forms based on values from a select, setting types, etc. that can be used in Jinja2 templates (but will not be required).

Gigaspoon is less "featureful" than other form-creation frameworks, so that the developers can have more power over the forms. Instead of automatically generating tags to be output, the framework urges you to write your own templates, assisted by the framework.

How?

It's actually super simple and relies on decorator functions to handle everything. Here's an example:

import gigaspoon as gs
import flask

app = flask.Flask(__name__)

@app.route("/", methods=["GET", "POST"])
@gs.set_methods("POST")
@gs.validator(gs.v.Regex("new", "hi"))
@gs.validator(gs.v.Regex("asdf", "[A-Za-z]+"))
@gs.base
def index(form):
    if form.is_form_mode():
        # Method is POST and form fields are valid
        print(form["asdf"])
        print(form["new"])
        return "hello!"
    else:
        return "hi!"
        # return flask.render_template("index.html")

@app.errorhandler(gs.e.FormError)
def handle_form_error(exc):
    return str(exc), 400

app.run()

Let's walk through the decorator "chain".

@gs.set_methods("POST") - This method ensures that forms will only be validated on POST requests. This function can take any amount of arguments and will check through all of them every request.

@gs.validator(gs.v.Regex("new", "hi")) - This method is our first validator. It checks for the key new on the inconing Flask form, assuming the current Flask request matches the set_methods() (defaulting to "POST" if the decorator wasn't called), then checks whether the incoming value matches the pattern.

@gs.base - This is a simple decorator provided as a convenience, which ensures that the first value for the called function is the incoming form, which can instead be accessed using flask.g.form.

form.is_form_mode() - Check if the incoming request matches the set methods. If it does, a value True is returned, otherwise False.

Installation

Currently, gigaspoon relies on no external dependencies other than Flask. It can be installed from source using pip install --user .. If you'd like to install a specific version (for example, version 0.1.0), checkout the Git tag and run pip from there:

git checkout v0.1.0
pip install --user .

Notes

Forms will be validated regardless of whether or not you use the values; the only thing that determines whether they're validated is whether or not they match the set_methods() value. This could change in the future by passing a "check" function to gs.validator() which determines whether or not the value will be used.