@pyscript/sw

^{PyScript Service Worker}

Documentation

This module provides a single, standalone, script able to bootstrap a Service Worker which can drive a whole site via Python code.

Please note the file must be available locally and it must not be loaded as a module, as a Service Worker is not a module.

Example

This is the bare minimal example of an index.html file at the root of the site.

<!doctype html>
<script src="./pyscript.sw.js"
        handler="./handler.py"
        config="./handler_config.toml"
        scope="."></script>

src is where the PyScript Service Worker is located.
handler is where Python code is located. This must provide a handle_request method that will be invoked per each browsing fetch operation. Such method should return a [body, status, headers] tuple where body is the content of the page, status is its HTTP status and headers contain the content-type or any other useful header.
config is an optional attribute that indicates packages to load, files to fetch, and all other usual py-config goodness.
scope (advanced use-case) is an optional attribute that indicates where the Service Worker operates. By default it operates from the same folder, and any subfolder, the pyscript.sw.js is.

How to update `handle_request`

Because the Service Worker, once activated, will persist over any further session, it is pretty hard to change its operating handler.

To do so, there are two options:

unregister the Service Worker, clear all browsing data per that domain and hard-refresh the browser
change and save your handler.py file and, once saved, reach the /pyscript.sw/update_handler via browser, or run the following code in console:

fetch('/pyscript.sw/update_handler')
  .then(b => b.text())
  .then(console.log, console.error);

This operation will be intercepted behind the scene and the new file will be parsed.

The result should be an OK response, with status 200, or an error message with status 500 handled by the console.error or visible within the page once reached.