FlaskSR

FlaskSR provides an easy way to add streaming HTTP Responses for Flask.

Why should you use this?

Most of the websites are trying to minimize "Time to First Paint". This can be done by streaming partial responses to client. FlaskSR enables this functionality in n easy way for Flask Web Framework. With FlaskSR you can start streaming partial HTTP responses depending on layout to client so that client starts seeing some content along the way instead of seeing all of the site's content at once.

Advantages:

Minimizes Time for first paint.
No impact on SEO - as nothing goes via AJAX calls.
Start rendering important part of your page first, so user sees important things first.

Installation

Install the extension with the following command:

$ pip install flasksr

FlaskSR in action

Usage

Once installed, the FlaskSR is easy to use. Let's walk through setting up a basic application. Also please note that this is a very basic guide: we will be taking shortcuts here that you should never take in a real application.

To begin we'll set up a Flask app:

from flask import Flask
from flasksr import BasicSR, Dom

app = Flask(__name__)


def render_menu():
    return """
        <ul style="list-style-type: none; margin: 0; padding: 0;">
            <li><a href="/">Home</a></li>
            <li><a href="#">News</a></li>
            <li><a href="#">Contact</a></li>
            <li><a href="#">About</a></li>
        </ul>
    """


def render_body():
    return """
        <div style="margin-top: 50px;">Hello World!</div>
    """

def render_first():
    return """
        <html>
            <head>
                <title>FlaskSR Example</title>
            </head>
            <body>
    """

def render_last():
    return """
            </body>
        </html>
    """


@app.route('/')
def hello():
    return BasicSR(
        Dom(render_first),
        Dom(render_menu),
        Dom(render_body),
        Dom(render_last)
    ).response


if __name__ == '__main__':
    app.run(host='0.0.0.0')

Above example shows a very basic top down response streaming with BasicSR For advanced usage when you want a particular part of your page to get rendered first you can use LayoutSR

Examples

You can find examples and sample usage here

Quickstart