User Guide

Migrating custom widget libraries

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Migrating custom widget libraries

These are migration guides aimed specifically at developers of third-party widgets.

Migrating from 6.0 to 7.0

For example migrations, see these PRs:

To avoid tying your development cycle to ipywidgets, we recommend starting the migration on a branch and keeping that branch open until ipywidgets 7.0 is released.

We also recommend testing the migration in a completely new notebook, rather than one that contains widgets that you instantiated with ipywidgets 6.0.


Start by updating the dependency in your to the latest release. To find the correct version number, go to the releases page on Github and cycle through the tags until you see the latest 7.0.0 tag.

Updating package.json

Next, we should update the JavaScript dependencies. The most important change for widget developers is that the JavaScript package for jupyter-widgets has been split between @jupyter-widgets/base and @jupyter-widgets/controls:

  • @jupyter-widgets/base contains the base widget classes and the layout classes
  • @jupyter-widgets/controls contains the widget classes for the user-facing widgets.

In your package.json, remove jupyter-js-widgets from your dependencies and add @jupyter-widgets/base. To find the correct version, go to the releases page and cycle through the tags until you see a tag called @jupyter-widgets/base@<version>. Do the same for @jupyter-widgets/controls if you think you have a dependency on it (e.g. if you create widgets that inherit from VBox or HBox or another user-facing widget).

Updating Webpack configuration

If you use Webpack to build the client-side library, your Webpack configuration file (probably at js/webpack.config.json) declares jupyter-js-widgets as an external dependency. You will need to change this in both the bundle for the notebook and the embeddable bundle. If you just need @jupyter-widgets/base, your external dependencies would be:

externals: ['@jupyter-widgets/base']

If you need both @jupyter-widgets/base and @jupyter-widgets/controls, include both packages in the array.

The cookiecutter template provides a sample configuration.

Updating the client-side code

If you now build the client-side code of your library, you will get many errors about missing jupyter-js-widgets dependencies. You need to replace every import of jupyter-js-widgets with an import of @jupyter-widgets/base (or, possibly, an import of @jupyter-widgets/controls).

Your imports should now look like one of the following (depending on how you normally import other modules):

widgets = require('@jupyter-widgets/base')
require(['@jupyter-widgets/base'], function(widgets) {
import * as widgets from '@jupyter-widgets/base'

All your widget models should also declare the attributes _view_module_version and _model_module_version. A minimal model now looks like:

var HelloModel = widgets.DOMWidgetModel.extend({
    defaults: _.extend(widgets.DOMWidgetModel.prototype.defaults(), {
        _model_name : 'HelloModel',
        _view_name : 'HelloView',
        _model_module : 'example_module',
        _view_module : 'example_module',
        _model_module_version : '~1.0.0',
        _view_module_version : '~1.0.0'

For embedding to work correctly, the module version needs to be a semantic version range that matches a release on NPM. The most common pattern is to request a version compatible with the version currently in your package.json by using, ~{{ version number }} for _model_module_version and _view_module_version. See the cookiecutter template for details.

Since you probably want to avoid repeating the module version in every widget, a common pattern is to import the version from package.json and prepend a ~. See ipyvolume for an example. If you do this, make sure that your webpack configuration includes a JSON loader. See the Webpack configuration for ipyvolume for an example.

Updating the notebook extension

Previously, the notebook extension (normally js/src/extension.js) required defining jupyter-js-widgets in the configuration for requirejs. This is no longer needed. See the cookiecutter template for an example of the correct requirejs configuration.

Updating the Python code

All widgets need to declare the following six traitlets:

class ExampleWidget(widgets.Widget):
    _model_name = Unicode('name of model in JS')
    _view_name = Unicode('name of view in JS')
    _model_module = Unicode('name your JS package')
    _view_module = Unicode('name your JS package')
    _model_module_version = Unicode('version of your JS bundle')
    _view_module_version = Unicode('version of your JS bundle')

It is likely that your widgets already declared a _model_name, _view_name, _model_module and _view_module. The _model_module and _view_module should be the name of your package on NPM (the value of the name field in your package.json). The _model_module_version and _view_module_version should be the version of your JavaScript client (the values of the version field in your package.json).

The _model_module_version and _view_module_version are used to find your JavaScript bundle when embedding widgets. The embed manager will look for the bundle at<module-name>@<module-version>/dist/index.js when it finds a widget.

Updating embedded widgets

There are now two options for embedding widgets in an HTML page outside of the notebook.

Embedding the standard widgets

If you are just embedding the standard widgets that come with ipywidgets, then you can simply include the following script tag:

<script src="*/dist/embed.js" crossorigin="anonymous"></script>

If you want to use a specific version of the embedder, you replace the @* with a semver range, such as @^0.9.0

Embedding custom widgets with RequireJS

In order to embed third-party widgets, you can use the RequireJS-based embedding. First, make sure that RequireJS is loaded on the page, for example:

<!-- Load require.js. Delete this if your page already loads require.js -->
<script src="" integrity="sha256-Ae2Vz/4ePdIu6ZyI/5ZGsYnb+m0JlOmKPjt6XZ9JJkA=" crossorigin="anonymous"></script>

Then include the following script, which defines the embedding libraries and runs the function to render widgets:

<script src="*/dist/embed-amd.js" crossorigin="anonymous"></script>

If you want to use a specific version of the embedder, you replace the @* with a semver range, such as @^0.9.0

If you need to embed custom widgets without using RequireJS, you'll need to compile your own embedding javascript that includes the third-party libraries.