Added provider-consumer example (multiple related packages).

.github/workflows/main.yml

@@ -29,6 +29,7 @@ jobs:
           - launcher
           - kernel-messaging
           - kernel-output
+          - leap_counter_extension
           - log-messages
           - main-menu
           - metadata-form
@@ -38,6 +39,8 @@ jobs:
           - shout-button-message
           - signals
           - state
+          - step_counter
+          - step_counter_extension
           - toolbar-button
           - toparea-text-widget
           - widgets

README.md

@@ -22,11 +22,14 @@
    1. [Kernel Messaging](#kernel-messaging)
    1. [Kernel Output](#kernel-output)
    1. [Launcher](#launcher)
+   1. [Leap Counter (Reusability 1C)](#leap-counter-reusability-1c)
    1. [Log Messages](#log-messages)
    1. [Main Menu](#main-menu)
    1. [Metadata Form](#metadata-form)
    1. [MIME Renderer](#mime-renderer)
    1. [Notifications](#notifications)
+   1. [Step Counter (Reusability 1A)](#step-counter-reusability-1a)
+   1. [Step Counter Extension (Reusability 1B)](#step-counter-extension-reusability-1b)
    1. [React Widget](#react-widget)
    1. _[Server Hello World](#server-hello-world)_
    1. [Settings](#settings)
@@ -114,6 +117,7 @@ Start with the [Hello World](hello-world) and then jump to the topic you are int
 - [Kernel Messaging](kernel-messaging)
 - [Kernel Output](kernel-output)
 - [Launcher](launcher)
+- [Leap Counter](leap_counter_extension)
 - [Log Messages](log-messages)
 - [Main Menu](main-menu)
 - [Metadata Form](metadata-form)
@@ -123,6 +127,8 @@ Start with the [Hello World](hello-world) and then jump to the topic you are int
 - [Server Hello World](server-extension)
 - [Settings](settings)
 - [Signals](signals)
+- [Step Counter (Reusability 1A)](step_counter)
+- [Step Counter Extension (Reusability 1B)](step_counter_extension)
 - [State](state)
 - [Toolbar item](toolbar-button)
 - [Widgets](widgets)
@@ -262,6 +268,17 @@ Start your extension from the Launcher.
 
 [![Launcher](launcher/preview.gif)](launcher)
 
+### [Leap Counter (Reusability 1C)](leap_counter_extension)
+
+Create your own reusable plugin components with Jupyter's "Provider-
+Consumer Pattern". This is one of three related extension examples
+that demonstrate JupyterLab's provider-consumer pattern, where plugins
+can depend on and reuse features from one another. The three packages
+that make up the complete example are "step_counter", "step_counter_extension",
+and "leap_counter_extension".
+
+[![Leap counter extension](step_counter/preview.png)](leap_counter_extension)
+
 ### [Log Messages](log-messages)
 
 Send a log message to the log console.
@@ -316,6 +333,28 @@ Use Signals to allow Widgets communicate with each others.
 
 [![Button with Signal](signals/preview.png)](signals)
 
+### [Step Counter (Reusability 1A)](step_counter)
+
+Create your own reusable plugin components with Jupyter's "Provider-
+Consumer Pattern". This is one of three related extension examples
+that demonstrate JupyterLab's provider-consumer pattern, where plugins
+can depend on and reuse features from one another. The three packages
+that make up the complete example are "step_counter", "step_counter_extension",
+and "leap_counter_extension".
+
+[![Step counter](step_counter/preview.png)](step_counter)
+
+### [Step Counter Extension (Reusability 1B)](step_counter_extension)
+
+Create your own reusable plugin components with Jupyter's "Provider-
+Consumer Pattern". This is one of three related extension examples
+that demonstrate JupyterLab's provider-consumer pattern, where plugins
+can depend on and reuse features from one another. The three packages
+that make up the complete example are "step_counter", "step_counter_extension",
+and "leap_counter_extension".
+
+[![Step counter extension](step_counter/preview.png)](step_counter_extension)
+
 ### [State](state)
 
 Use State persistence in an extension.

context-menu/src/index.ts

@@ -17,8 +17,9 @@ const extension: JupyterFrontEndPlugin<void> = {
       caption: "Example context menu button for file browser's items.",
       icon: buildIcon,
       execute: () => {
-        const file = factory.tracker.currentWidget?.selectedItems().next()
-          .value;
+        const file = factory.tracker.currentWidget
+          ?.selectedItems()
+          .next().value;
 
         if (file) {
           showDialog({

documents/src/model.ts

@@ -395,7 +395,7 @@ export class ExampleDoc extends YDocument<ExampleDocChange> {
       ? data
         ? JSON.parse(data)
         : { x: 0, y: 0 }
-      : data ?? '';
+      : (data ?? '');
   }
 
   /**

leap_counter_extension/.copier-answers.yml

@@ -0,0 +1,15 @@
+# Changes here will be overwritten by Copier; NEVER EDIT MANUALLY
+_commit: v4.2.0
+_src_path: https://github.com/jupyterlab/extension-template
+author_email: [email protected]
+author_name: My Name
+has_binder: false
+has_settings: false
+kind: frontend
+labextension_name: leap_counter_extension
+project_short_description: Adds a leap counter/button (1 of 3 related examples). This
+    extension holds the UI/interface.
+python_name: leap_counter_extension
+repository: ''
+test: true
+

leap_counter_extension/.gitignore

@@ -0,0 +1,125 @@
+*.bundle.*
+lib/
+node_modules/
+*.log
+.eslintcache
+.stylelintcache
+*.egg-info/
+.ipynb_checkpoints
+*.tsbuildinfo
+leap_counter_extension/labextension
+# Version file is handled by hatchling
+leap_counter_extension/_version.py
+
+# Integration tests
+ui-tests/test-results/
+ui-tests/playwright-report/
+
+# Created by https://www.gitignore.io/api/python
+# Edit at https://www.gitignore.io/?templates=python
+
+### Python ###
+# Byte-compiled / optimized / DLL files
+__pycache__/
+*.py[cod]
+*$py.class
+
+# C extensions
+*.so
+
+# Distribution / packaging
+.Python
+build/
+develop-eggs/
+dist/
+downloads/
+eggs/
+.eggs/
+lib/
+lib64/
+parts/
+sdist/
+var/
+wheels/
+pip-wheel-metadata/
+share/python-wheels/
+.installed.cfg
+*.egg
+MANIFEST
+
+# PyInstaller
+#  Usually these files are written by a python script from a template
+#  before PyInstaller builds the exe, so as to inject date/other infos into it.
+*.manifest
+*.spec
+
+# Installer logs
+pip-log.txt
+pip-delete-this-directory.txt
+
+# Unit test / coverage reports
+htmlcov/
+.tox/
+.nox/
+.coverage
+.coverage.*
+.cache
+nosetests.xml
+coverage/
+coverage.xml
+*.cover
+.hypothesis/
+.pytest_cache/
+
+# Translations
+*.mo
+*.pot
+
+# Scrapy stuff:
+.scrapy
+
+# Sphinx documentation
+docs/_build/
+
+# PyBuilder
+target/
+
+# pyenv
+.python-version
+
+# celery beat schedule file
+celerybeat-schedule
+
+# SageMath parsed files
+*.sage.py
+
+# Spyder project settings
+.spyderproject
+.spyproject
+
+# Rope project settings
+.ropeproject
+
+# Mr Developer
+.mr.developer.cfg
+.project
+.pydevproject
+
+# mkdocs documentation
+/site
+
+# mypy
+.mypy_cache/
+.dmypy.json
+dmypy.json
+
+# Pyre type checker
+.pyre/
+
+# End of https://www.gitignore.io/api/python
+
+# OSX files
+.DS_Store
+
+# Yarn cache
+.yarn/

leap_counter_extension/.prettierignore

@@ -0,0 +1,6 @@
+node_modules
+**/node_modules
+**/lib
+**/package.json
+!/package.json
+leap_counter_extension

leap_counter_extension/.yarnrc.yml

@@ -0,0 +1 @@
+nodeLinker: node-modules

leap_counter_extension/README.md

@@ -0,0 +1,32 @@
+# Leap Counter (Reusability 1C) (leap_counter_extension)
+
+This multi-part example comes from the [Jupyter Plugin System guide](https://jupyterlab.readthedocs.io/en/latest/extension/plugin_system.html),
+and demonstrates Jupyter's provider/consumer pattern. You can find
+details about this example on that page.
+
+This is one of three related extension examples that demonstrate
+JupyterLab's provider-consumer pattern, where plugins can depend
+on and reuse features from one another. The three packages that
+make up the complete example are:
+
+1. The step_counter package. This package holds a token, a
+   class + an interface that make up a stock implementation of
+   the "step_counter" service, and a provider plugin that
+   makes an instance of the Counter available to JupyterLab
+   as a service object.
+
+2. The step_counter_extension package, that holds a
+   UI/interface in JupyterLab for users to count their steps that
+   connects with/consumes the step_counter service object via a
+   consumer plugin.
+
+3. (\*) The leap_counter_extension package (this one), that holds an alternate
+   way for users to count steps (a leap is 5 steps). Like the step_counter_extension
+   package, this holds a UI/interface in JupyterLab, and a consumer
+   plugin that also requests/consumes the step_counter service
+   object. The leap_counter_extension package demonstrates how
+   an unrelated plugin can depend on and reuse features from
+   an existing plugin. Users can install either the
+   step_counter_extension, the leap_counter_extension or both
+   to get whichever features they prefer (with both reusing
+   the step_counter service object).

leap_counter_extension/babel.config.js

@@ -0,0 +1 @@
+module.exports = require('@jupyterlab/testutils/lib/babel.config');

leap_counter_extension/install.json

@@ -0,0 +1,5 @@
+{
+  "packageManager": "python",
+  "packageName": "leap_counter_extension",
+  "uninstallInstructions": "Use your Python package manager (pip, conda, etc.) to uninstall the package leap_counter_extension"
+}

leap_counter_extension/jest.config.js

@@ -0,0 +1,28 @@
+const jestJupyterLab = require('@jupyterlab/testutils/lib/jest-config');
+
+const esModules = [
+  '@codemirror',
+  '@jupyter/ydoc',
+  '@jupyterlab/',
+  'lib0',
+  'nanoid',
+  'vscode-ws-jsonrpc',
+  'y-protocols',
+  'y-websocket',
+  'yjs'
+].join('|');
+
+const baseConfig = jestJupyterLab(__dirname);
+
+module.exports = {
+  ...baseConfig,
+  automock: false,
+  collectCoverageFrom: [
+    'src/**/*.{ts,tsx}',
+    '!src/**/*.d.ts',
+    '!src/**/.ipynb_checkpoints/*'
+  ],
+  coverageReporters: ['lcov', 'text'],
+  testRegex: 'src/.*/.*.spec.ts[x]?$',
+  transformIgnorePatterns: [`/node_modules/(?!${esModules}).+`]
+};

leap_counter_extension/leap_counter_extension/__init__.py

@@ -0,0 +1,16 @@
+try:
+    from ._version import __version__
+except ImportError:
+    # Fallback when using the package in dev mode without installing
+    # in editable mode with pip. It is highly recommended to install
+    # the package from a stable release or in editable mode: https://pip.pypa.io/en/stable/topics/local-project-installs/#editable-installs
+    import warnings
+    warnings.warn("Importing 'leap_counter_extension' outside a proper installation.")
+    __version__ = "dev"
+
+
+def _jupyter_labextension_paths():
+    return [{
+        "src": "labextension",
+        "dest": "leap_counter_extension"
+    }]