falk 0.7.2

Responsive server components in Python

falk

falk is a Python based web framework for responsive server components. falk components hold their state cryptographically signed on the client side. This makes the server fully stateless and easy to scale.

falk components can contain business logic, HTML markup, external and inline stylesheets and scripts, can communicate with the server over HTTP REST or websockets.

Demo

# pip install uvicorn[websocket] falk
# uvicorn --app-dir=./ demo:app

from falk.components import HTML5Base
from falk.asgi import get_asgi_app


def Counter(initial_render, props, state, add_callback):

    # initialize state object
    if initial_render:
        state.update({
            "count": props.get("initial_value", 0),
        })

    # this callback gets called when the button is clicked
    # (callbacks can be sync or async)
    def increment(args):
        state["count"] += args[0]

    add_callback(increment)

    return """
        <button onclick="{{ falk.run_callback('increment', [1]) }}">
            Count: <strong>{{ state.count }}</strong>
        </button>
    """


def Index(HTML5Base=HTML5Base, Counter=Counter):
    return """
        <link rel="stylesheet" href="https://cdn.jsdelivr.net/npm/@picocss/pico@2/css/pico.min.css">

        <style>
            .container {
                margin: 0 auto;
                margin-top: 2em;
            }

            button {
                padding: 5px 10px;
                margin-bottom: 10px;
            }
        </style>

        <HTML5Base title="falk Hello World">
            <div class="container">
                <h1>falk Hello World</h1>

                {% for i in range(5) %}
                    <Counter initial_value="{{ i }}" />
                    <br/>
                {% endfor %}
            </div>
        </HTML5Base>
    """


def configure_app(set_setting, add_route):
    set_setting("debug", True)

    add_route("/", Index)


app = get_asgi_app(configure_app)