JupyterLab Extensions by Examples

Goal
Develop by Examples
1. CodeMirror extension
2. Commands
3. Command Palette
4. Completer
5. Main Widget Content Header
6. Context Menu
7. Custom Log Console
8. Datagrid
9. Collaborative Document
10. Hello World
11. Kernel Messaging
12. Kernel Output
13. Launcher
14. Log Messages
15. Main Menu
16. Metadata Form
17. MIME Renderer
18. Notifications
19. React Widget
20. Server Hello World
21. Settings
22. Signals
23. State
24. Toolbar Item
25. Widgets
Prerequisites
Develop and Use the Examples
Test the Examples
Install a Published Extension
About JupyterLab
Credits
Community Guidelines and Code of Conduct

TL;DR

The goal of this repository is to show how to develop extensions for JupyterLab, presented as short tutorial series.

To get started:

# clone the repository
git clone https://github.com/jupyterlab/extension-examples.git jupyterlab-extension-examples

# go to the extension examples folder
cd jupyterlab-extension-examples

# create a new environment
conda env create

# activate the environment
conda activate jupyterlab-extension-examples

# go to the hello world example
cd hello-world

# Required to deal with Yarn 3 workspace rules
touch yarn.lock

# install the extension in editable mode
python -m pip install -e .

# install your development version of the extension with JupyterLab
jupyter labextension develop . --overwrite

# build the TypeScript source after making changes
jlpm run build

# start JupyterLab
jupyter lab

The examples currently target JupyterLab 4.0 or later.

If you would like to use the examples with JupyterLab 3.x, check out the 3.x branch.

If you would like to use the examples with JupyterLab 2.x, check out the 2.x branch.

If you would like to use the examples with JupyterLab 1.x, check out the 1.x branch.

Note that the 1.x, 2.x and 3.x branches are not updated anymore.

Develop by Examples

You may find it easier to learn how to create extensions by examples, instead of going through the documentation.

Start with the Hello World and then jump to the topic you are interested in.

You can expect from each example:

An explanation of its functionality.
An image or screencast showing its usage.
The list of used JupyterLab API and Extension Points.
Explanations of the internal working, illustrated with code snippets.

We have structured the examples based on the extension points. Browse the previews below or skip them and jump directly to the sections for developers.

You are welcome to open any issue or pull request.

CodeMirror extension

Add a configurable CodeMirror extension.

Completer

Customize tab autocomplete data sources.

Main Widget Content Header

Put widgets at the top of a main JupyterLab area widget.

Context Menu

Add a new button to an existent context menu.

Collaborative Document

Create new documents and make them collaborative.

Hello World

Set up the development environment and print to the console.

Kernel Messaging

Interact with a kernel from an extension.

Kernel Output

Render kernel messages in an OutputArea.

Metadata Form

Add user interface to edit cell or notebook metadata.

MIME Renderer

Add a MIME renderer for mp4 content to the application.

Server Hello World

Create a minimal extension with backend (i.e. server) and frontend parts.

Settings

Create and use new Settings for your extension.

Signals

Use Signals to allow Widgets communicate with each others.

Toolbar Item

Add a new button to the notebook toolbar.

Widgets

Add a new Widget element to the main window.

Prerequisites

Writing an extension requires basic knowledge of JavaScript, Typescript and potentially Python.

Don't be scared of Typescript, even if you never coded in TypeScript before you touch JupyterLab you may find it easier to understand than pure JavaScript if you have a basic understanding of object oriented programming and types.

These examples are developed and tested on top of JupyterLab. You can create a conda environment to get started after cloning this repository.

conda env create && \
  conda activate jupyterlab-extension-examples

The previous command will use the environment.yml file as requirements for the environment.

Develop and Use the Examples

Build and Install all Examples at once

jlpm
jlpm build-ext
jlpm install-py
jlpm install-ext
jupyter lab

To rebuild all the extensions:

jlpm build-ext

To clean the lib folders:

jlpm clean-ext

Build and Install one Example

Go to the example directory you want to install, e.g. cd ./hello-world, and run the following commands:

touch yarn.lock
pip install -e .
jupyter labextension develop . --overwrite

Rebuild the extension:

jlpm run build

You can now start JupyterLab and check if your extension is working fine:

jupyter lab

Change the Sources

If you want to develop and iterate on the code, you will need to open 2 terminals.

In terminal 1, go to the extension folder and run the following:

jlpm watch

Then in terminal 2, start JupyterLab:

jupyter lab

From there, you can change your extension source code, it will be recompiled, and you can refresh your browser to see your changes.

We are using embedme to embed code snippets into the markdown READMEs. If you make changes to the source code, ensure you update the README and run jlpm embedme from the root of the repository to regenerate the READMEs.

Update extension template

Execute from the example root folder:

./scripts/update-template.sh

Then fix the conflicts.

Test the Examples

The examples are automatically tested for:

Homogeneous configuration:
Configuration files are compared to the reference ones of the hello-world example
TypeScript code lint
Installation in JupyterLab:
The installation is checked by listing the installed extension and running JupyterLab with the helper python -m jupyterlab.browser_check
Integration test:
Those tests are emulating user action in JupyterLab to check the extension is behaving as expected.
The tests are defined in the ui-tests subfolder within each example. This is possible thanks to a tool called playwright.

Install a Published Extension

Once your extension is published on pypi.org (outside of this scope), you can install it with the following command:

pip install <published_extension>

About JupyterLab

JupyterLab can be used as a platform to combine existing data-science components into a new powerful application that can be deployed remotely to many users. Some of the higher level components that can be used are text editors, terminals, notebooks, interactive widgets, filebrowser, renderers for different file formats that provide access to an enormous ecosystem of libraries from different languages.

Complementary to these examples, you can rely on the official JupyterLab documentation.

Credits

We would like to thank MMesch for initiating this work, as well as everyone else who contributed!

Community Guidelines and Code of Conduct

This examples repository is a Jupyter project and follows the Jupyter Community Guides and Code of Conduct.

Reviews

Repository Details