Launch in jupyterlite

docs/conf.py

@@ -111,6 +111,7 @@
         "binderhub_url": "https://mybinder.org",
         "colab_url": "https://colab.research.google.com/",
         "deepnote_url": "https://deepnote.com/",
+        "retrolite_url": "/lite/retro/notebooks/",
         "notebook_interface": "jupyterlab",
         "thebe": True,
         # "jupyterhub_url": "https://datahub.berkeley.edu",  # For testing

docs/launch.md

@@ -85,7 +85,56 @@ html_theme_options = {
 This will create a new Deepnote project every time you click the launch button.
 ```
 
+## JupyterLite and RetroLite
 
+```{warning}
+JupyterLite and RetroLite are experimental, and their behavior and configuration
+may change over time!
+Please provide feedback and suggestions.
+```
+
+To add [RetroLite](https://jupyterlite-sphinx.readthedocs.io/en/latest/retrolite.html) links to your page, add the following configuration:
+
+```python
+html_theme_options = {
+    ...
+    "launch_buttons": {
+        "retrolite_url": "/lite/retro/notebooks/"
+    },
+    ...
+}
+```
+[JupyterLite](https://jupyterlite.readthedocs.io/) allows you to run a Jupyter environment entirely in the browser via [WebAssembly](https://webassembly.org/) and [Pyodide](https://pyodide.org/en/stable/).
+To use JupyterLite in your launch buttons, you'll first need to take these steps:
+1. **Install [`jupyterlite-sphinx`](https://jupyterlite-sphinx.readthedocs.io/)**. And configure it to publish a JupyterLab environment as part of your published Jupyter Book environment by [following the installation instructions](https://jupyterlite-sphinx.readthedocs.io/en/latest/installation.html).
+2. **Configure JupyterLite Sphinx to use your site content as a folder**. You can configure JupyterLite Sphinx to look for notebooks in a specified directory. Put the notebooks you wish to expose in that directory, and [follow these configuration instructions](https://jupyterlite-sphinx.readthedocs.io/en/latest/configuration.html#jupyterlite-content).
+```
+There are two different interfaces that you can activate with JupyterLite, each is described below.
+### JupyterLab via JupyterLite
+To add JupyterLab via JupyterLite to your launch buttons, use the following configuration:
+```python
+html_theme_options = {
+    ...
+    "launch_buttons": {
+        "jupyterlite_url": "/lite/lab/notebooks/"
+    },
+    ...
+}
+```
+Where `notebooks/` is a folder with a collection of Jupyter Notebooks you'd like to serve with JupyterLite.
+### RetroLab via JupyterLite
+RetroLab mimics the classic Jupyter Notebook interface, but using JupyterLab components.
+It will be the default Notebook interface in the near future.
+To add RetroLab via JupyterLite to your launch buttons, use the following configuration:
+```python
+html_theme_options = {
+    ...
+    "launch_buttons": {
+        "jupyterlite_url": "/lite/retro/notebooks/"
+    },
+    ...
+}
+```
 ## Live code cells with Thebe
 
 [Thebe](http://thebe.readthedocs.org/) converts your static code blocks into

src/sphinx_book_theme/header_buttons/launch.py

@@ -103,6 +103,9 @@ def add_launch_buttons(
     binderhub_url = launch_buttons.get("binderhub_url", "").strip("/")
     colab_url = launch_buttons.get("colab_url", "").strip("/")
     deepnote_url = launch_buttons.get("deepnote_url", "").strip("/")
+    # retrolite_url could be absolute but without a domain, so we only
+    # strip trailing slashes, not leading ones
+    retrolite_url = launch_buttons.get("retrolite_url", "").rstrip("/")
     if binderhub_url:
         url = (
             f"{binderhub_url}/v2/gh/{org}/{repo}/{branch}?"
@@ -161,6 +164,18 @@ def add_launch_buttons(
             }
         )
 
+    if retrolite_url:
+        url = f"{retrolite_url}?path={path_rel_repo}"
+        launch_buttons_list.append(
+            {
+                "type": "link",
+                "text": "RetroLite",
+                "tooltip": "Launch via RetroLite",
+                "icon": "_static/images/logo_jupyterlite.svg",
+                "url": url,
+            }
+        )
+
     # Add thebe flag in context
     if launch_buttons.get("thebe", False):
         launch_buttons_list.append(

tests/sites/base/conf.py

@@ -27,6 +27,7 @@
         "jupyterhub_url": "https://datahub.berkeley.edu",
         "colab_url": "https://colab.research.google.com",
         "deepnote_url": "https://deepnote.com",
+        "retrolite_url": "/lite/retro/notebooks/",
         "notebook_interface": "jupyterlab",
         "thebe": True,
     },