Server-driven UI kit for Python with async support


Keywords
async, python, server-driven-ui, ui
License
MIT
Install
pip install schorle==0.0.25

Documentation

logo

Schorle (pronounced as ˈʃɔʁlə) is a server-driven UI kit for Python with async support.


Latest Python Release We use black for formatting codecov


Note: This project is in an early stage of development. It is not ready for production use.

Installation

pip install schorle

Usage

Take a look at the examples directory.

Concepts

We use the following approaches to handle various cases:

  • Rendering HTML elements is done using Python functions.

Elements

In contrast to using templating engines, Schorle uses Python functions to create HTML elements. This approach allows for better type checking and code completion.

from schorle.text import text
from schorle.element import div
from schorle.rendering_context import rendering_context


def my_element():
    with div():
        text("Hey!")


with rendering_context() as ctx:
    my_element()
    print(ctx.to_lxml())

Although this might seem a bit complicated, in actual applications it works nicely when Elements are used inside the Components.

Components

Components are reusable parts of the UI. They are created using Python classes.

from schorle.component import Component
from schorle.element import div
from schorle.text import text


class MyComponent(Component):
    def render(self):
        with div():
            text("Hey!")


print(
    MyComponent().to_string()
)

Note that the render method is used to define the structure of the component.

Since render is a method, you can use all the power of Python to create dynamic components, like this:

from schorle.component import Component
from schorle.element import div, span
from schorle.text import text


class MyComponent(Component):
    def render(self):
        with div():
            for idx in range(10):
                with span():
                    text("Hey!") if idx % 2 == 0 else text("Ho!")

Pretty much any Python code can be used to create the structure of the component.

Running the application

Schorle application is a thin wrapper around FastAPI. To run the application, use uvicorn:

uvicorn examples.static:app --reload

Under the hood, Schorle uses FastAPI, so you can use all the features provided by FastAPI. To access the FastAPI application instance, use the backend attribute:

from schorle.app import Schorle

app = Schorle()

app.backend.add_middleware(...)  # add FastAPI middleware

Dev reload

Schorle supports dev reload out of the box. To enable it, use the --reload flag:

uvicorn examples.todo:app --reload

On any change in the code, the server will restart automatically, and the client will re-fetch the page.

Tech stack

On the backend:

On the frontend:

Optimizing the site performance

Schorle has several features to optimize the site performance:

  • Client-server communications are happening over WebSockets and inside a Worker
  • CSS/JS libraries are served as brotli-compressed files

Roadmap

  • Add dev reload
  • Add server communication channel
  • Add state (global)
  • Add state at component level
  • Add more elements
  • Add support for icons
  • Add convenient attributes API
  • Add more examples
  • Add tests
  • Add CI/CD
  • Add documentation
  • Add support for Plotly-based charts
  • Add support for Vega-based charts
  • Refactor the imports