Embedding Jupyter Widgets in Other Contexts than the Notebook¶

参考：Embedding Jupyter Widgets in Other Contexts than the Notebook

Jupyter interactive widgets can be serialized and embedded into

static web pages
sphinx documentation
html-converted notebooks on nbviewer

Here, we discuss embedding widgets using the custom widget manager in the @jupyter-widgets/html-manager npm package. Two embedders are provided:

A basic embedder that only embeds standard controls, but can be used on any web page
An embedder that uses RequireJS, and can embed standard and custom widgets

Embedding Widgets in HTML Web Pages¶

The classic notebook interface provides a Widgets menu for generating an HTML snippet that can be embedded into any static web page:

The menu provides three sets of actions

Save Notebook Widget State and Clear Notebook Widget State
Download Widget State
Embed Widgets

Save Notebook Widget State¶

A notebook file may be saved with the current widget state as metadata. This allows the notebook file to be rendered with rendered widgets (see the section about Sphinx below, for example). To save a notebook with the current widget state, use the Save Notebook Widget State menu item.

In order to delete old saved state and save new state to the notebook, do the following in order:

Use the Clear Notebook Widget State menu and save the notebook. This clears the metadata from the notebook file.
Restart the kernel and refresh the page. This clears the old widget state from the widget manager on the page.
Create whatever widgets you'd like, and use Save Notebook Widget State and save the notebook. This saves the new widget state to the notebook file.

Embeddable HTML Snippet¶

The Embed widgets menu item provides a dialog containing an HTML page which embeds the current widgets. In order to support custom widgets, it uses the RequireJS embedder.

This HTML snippet is composed of multiple <script> tags embedded into an HTML document:

The first script tag loads RequireJS from a CDN. If you already have RequireJS on the page, you can delete this script tag.
The second script tag loads the RequireJS widget embedder. This defines appropriate modules and then sets up a function to render all of the widget views included on the page. If you are only embedding standard widgets and do not want to use RequireJS, you can replace these first two script tags with a script tag loading the standard embedder.
The next script tag is a script tag with mime type application/vnd.jupyter.widget-state+json that contains the state of all the widget models currently in use. The JSON schema for the content of this script tag is found in the @jupyter-widgets/schema npm package.
Then there are a number of script tags, each with mime type application/vnd.jupyter.widget-view+json, corresponding to the views which you want to display on the web page. These script tags must be in the body of the page, and are replaced with the rendered widgets. The JSON schema for the content of these script tags is found in the @jupyter-widgets/schema npm package.

The Embed Widgets action currently creates one of these script tags for each view displayed in the notebook. If you'd like to lay out the views, or include only some of them, you can delete or include these script tags as you wish.

In order to clear widget state from the frontend so that it does not show up in the embedding, restart the kernel and then refresh the page, in that order.

Python interface¶

Embeddable code for the widgets can also be produced from Python. The ipywidgets.embed module provides several functions for embedding widgets into HTML documents programmatically.

Use embed_minimal_html to create a simple, stand-alone HTML page:

from ipywidgets import IntSlider
from ipywidgets.embed import embed_minimal_html

slider = IntSlider(value=40)
embed_minimal_html('export.html', views=[slider], title='Widgets export')

This creates the stand-alone file export.html. To view the file, either start an HTTP server, such as the HTTP server in the Python standard library, or just open it in your web browser (by double-clicking on the file, or by writing file:///path/to/file in your browser search bar).

You will sometimes want greater granularity than that afforded by embed_minimal_html. Often, you want to control the structure of the HTML document in which the widgets are embedded. For this, use embed_data to get JSON exports of specific parts of the widget state. You can embed these in an HTML template:

import json

from ipywidgets import IntSlider
from ipywidgets.embed import embed_data

s1 = IntSlider(max=200, value=100)
s2 = IntSlider(value=40)
data = embed_data(views=[s1, s2])

html_template = """
<html>
  <head>

    <title>Widget export</title>

    <!-- Load RequireJS, used by the IPywidgets for dependency management -->
    <script 
      src="https://cdnjs.cloudflare.com/ajax/libs/require.js/2.3.4/require.min.js" 
      integrity="sha256-Ae2Vz/4ePdIu6ZyI/5ZGsYnb+m0JlOmKPjt6XZ9JJkA=" 
      crossorigin="anonymous">
    </script>

    <!-- Load IPywidgets bundle for embedding. -->
    <script
      data-jupyter-widgets-cdn="https://unpkg.com/"
      data-jupyter-widgets-cdn-only
      src="https://cdn.jsdelivr.net/npm/@jupyter-widgets/html-manager@*/dist/embed-amd.js" 
      crossorigin="anonymous">
    </script>

    <!-- The state of all the widget models on the page -->
    <script type="application/vnd.jupyter.widget-state+json">
      {manager_state}
    </script>
  </head>

  <body>

    <h1>Widget export</h1>

    <div id="first-slider-widget">
      <!-- This script tag will be replaced by the view's DOM tree -->
      <script type="application/vnd.jupyter.widget-view+json">
        {widget_views[0]}
      </script>
    </div>

    <hrule />

    <div id="second-slider-widget">
      <!-- This script tag will be replaced by the view's DOM tree -->
      <script type="application/vnd.jupyter.widget-view+json">
        {widget_views[1]}
      </script>
    </div>

  </body>
</html>
"""

manager_state = json.dumps(data['manager_state'])
widget_views = [json.dumps(view) for view in data['view_specs']]
rendered_template = html_template.format(manager_state=manager_state, widget_views=widget_views)
with open('export.html', 'w') as fp:
    fp.write(rendered_template)

The web page needs to load RequireJS and the Jupyter widgets HTML manager. You then need to include the manager state in a <script> tag of type application/vnd.jupyter.widget-state+json, which can go in the head of the document. For each widget view, place a <script> tag of type application/vnd.jupyter.widget-view+json in the DOM element that should contain the view. The widget manager will replace each <script> tag with the DOM tree corresponding to the widget.

In this example, we used a Python string for the template, and used the format method to interpolate the state. For embedding in more complex documents, you may want to use a templating engine like Jinja2.

We also change the CDN from its default of jsdelivr to use unpkg by setting the data-jupyter-widgets-cdn attribute.

What's more, we only load modules from the CDN by setting the data-jupyter-widgets-cdn-only attribute.

In all embedding functions in ipywidgets.embed, the state of all widgets known to the widget manager is included by default. You can alternatively pass a reduced state to use instead. This can be particularly relevant if you have many independent widgets with a large state, but only want to include the relevant ones in your export. To include only the state of specific views and their dependencies, use the function dependency_state:

from ipywidgets.embed import embed_minimal_html, dependency_state

s1 = IntSlider(max=200, value=100)
s2 = IntSlider(value=40)
embed_minimal_html('export.html', views=[s1, s2], state=dependency_state([s1, s2]))

Embedding Widgets in the Sphinx HTML Documentation¶

As of ipywidgets 6.0, Jupyter interactive widgets can be rendered in Sphinx html documentation. Two means of achieving this are provided:

Using the Jupyter Sphinx Extension¶

The jupyter_sphinx extension enables jupyter-specific features in sphinx. It can be installed with pip and conda.

In the conf.py sphinx configuration file, add jupyter_sphinx to the list of enabled extensions.

Then use the jupyter-execute directive to embed the output of code execution in your documentation

.. jupyter-execute::

  from ipywidgets import VBox, jsdlink, IntSlider, Button
  s1, s2 = IntSlider(max=200, value=100), IntSlider(value=40)
  b = Button(icon='legal')
  jsdlink((s1, 'value'), (s2, 'max'))
  VBox([s1, s2, b])

Using the `nbsphinx` Project¶

The nbsphinx Sphinx extension provides a source parser for *.ipynb files. Custom Sphinx directives are used to show Jupyter Notebook code cells (and of course their results) in both HTML and LaTeX output. In the case of the HTML output, Jupyter Interactive Widgets are also supported.

For notebooks that are executed by nbsphinx the widget state is automatically generated. For others, it is a requirement that the notebook was correctly saved with the special "Save Notebook Widget State" action in the widgets menu.

The necessary JavaScript code is automatically embedded in the generated HTML files. A custom URL or a local JavaScript file can be specified with the nbsphinx_widgets_path configuration option. For more configuration options, have a look at the documentation.

Rendering Interactive Widgets on nbviewer ¶

If your notebook was saved with the special "Save Notebook Widget State" action in the Widgets menu, interactive widgets displayed in your notebook should also be rendered on nbviewer.

See e.g. the Widget List example from the documentation.

The Case of Custom Widget Libraries¶

Custom widgets can also be rendered on nbviewer, static HTML and RTD documentation. An illustration of this is the http://jupyter.org/widgets gallery.

The widget embedder attempts to fetch the model and view implementation of the custom widget from the npm CDN https://cdn.jsdelivr.net/npm by default. The URL that is requested for, e.g. the bqplot module name, with the semver range ^2.0.0 is

https://cdn.jsdelivr.net/npm/bqplot@^2.0.0/dist/index.js

which holds the webpack bundle for the bqplot library.

While the default CDN is using https://cdn.jsdelivr.net/npm it can be configured by setting the optional data-jupyter-widgets-cdn attribute for script tag which loads embed-amd.js, as shown in the example above.

While the default strategy is loading modules from the same site, and then falling back to CDN. This can be configured by setting the optional data-jupyter-widgets-cdn-only attribute for script tag which loads embed-amd.js as shown in the example above too.

The widget-cookiecutter template project contains a template project for a custom widget library following the best practices for authoring widgets, which ensure that your custom widget library can render on nbviewer.

Using `jupyter-widgets-controls` in web contexts¶

The core jupyter-widgets-controls library, the JavaScript package of ipywidgets, is agnostic to the context in which it is used (Notebook, JupyterLab, static web page). For each context, we specialize the base widget manager implemented in @jupyter-widgets/base to provide the logic for

where widgets should be displayed,
how to retrieve information about their state.

Specifically:

The widgetsnbextension Python package provides the implementation of a specialized widget manager for the classic Jupyter notebook, and the packaging logic as a notebook extension.
The @jupyter-widgets/jupyterlab-manager npm package provides the implementation of a specialized widget manager for the context of JupyterLab, and the packaging logic as a lab extension.
The embed manager implemented in the @jupyter-widgets/html-manager npm package is a specialization of the base widget manager used for the static embedding of widgets used by the Sphinx extension, nbviewer, and the "Embed Widgets" command discussed above.

We provide additional examples of specializations of the base widget manager implementing other usages of Jupyter widgets in web contexts.

The web1 example is a simplistic example showcasing the use of Jupyter widgets in a web context.
The web2 example is a simple example making use of the application/vnd.jupyter.widget-state+json mime type.
The web3 example showcases how communication with a Jupyter kernel can happen in a web context outside of the notebook or jupyterlab contexts.
The web-tmpnb example makes use of the tmpnb service to spawn a Jupyter server, request a kernel from this server and implement the same feature as the web3 example.

品味人生

Embedding Jupyter Widgets in Other Contexts than the Notebook¶

Embedding Widgets in HTML Web Pages¶

Save Notebook Widget State¶

Embeddable HTML Snippet¶

Widget State JSON¶

Python interface¶

Embedding Widgets in the Sphinx HTML Documentation¶

Using the Jupyter Sphinx Extension¶

Using the `nbsphinx` Project¶

Rendering Interactive Widgets on nbviewer ¶

The Case of Custom Widget Libraries¶

Using `jupyter-widgets-controls` in web contexts¶

品味人生

Embedding Jupyter Widgets in Other Contexts than the Notebook¶

Embedding Widgets in HTML Web Pages¶

Save Notebook Widget State¶

Embeddable HTML Snippet¶

Widget State JSON¶

Python interface¶

Embedding Widgets in the Sphinx HTML Documentation¶

Using the Jupyter Sphinx Extension¶

Using the nbsphinx Project¶

Rendering Interactive Widgets on nbviewer¶

The Case of Custom Widget Libraries¶

Using jupyter-widgets-controls in web contexts¶

Using the `nbsphinx` Project¶

Rendering Interactive Widgets on nbviewer ¶

Using `jupyter-widgets-controls` in web contexts¶