Getting Set Up

The Bokeh project encompasses two major components: the Bokeh package source code, written in Python, and the BokehJS client-side library, written in CoffeeScript. Accordingly, development of Bokeh is slightly complicated by the fact that BokehJS requires an explicit compilation step to render the CoffeeScript source into deployable JavaScript.

For this reason, in order to develop Bokeh from a source checkout, you must first be able to build BokehJS.

Cloning the Repository

The source code for the Bokeh project is hosted on GitHub. To clone the source repository, issue the following command:

git clone https://github.com/bokeh/bokeh.git

This will create a bokeh directory at your location. This bokeh directory is referred to as the “source checkout” for the remainder of this document.

Building BokehJS

The BokehJS build process is handled by Gulp, which in turn depends on Node.js. Gulp is used to compile CoffeeScript and Less (CSS) sources (as well as Eco templates), and to combine these resources into optimized and minified bokeh.js and bokeh.css files.

Install npm and node

First, install Node.js and npm (node package manager). You can download and install these directly, or use conda to install them from the Bokeh channel on anaconda.org:

conda install -c bokeh nodejs

Alternatively, on Ubuntu you can use apt-get:

apt-get install npm node

Install Gulp and necessary plugins

Once you have npm and Node.js installed, you must use them to install the required dependencies before you can build BokehJS. Execute the following commands:

cd bokehjs
npm install

This command will install the necessary packages into the node_modules subdirectory (and list them as devDependencies in package.json).

If bokehjs fails, please check if you are working inside the bokehjs directory.

At this point you can typically use the setup.py script at the top level of the source checkout to manage building and installing BokehJS as part of the complete Bokeh library (see Python Setup).

However, if you want to work on the BokehJS sources or use BokehJS as a standalone library, then you need to use Gulp to build the BokehJS library as shown below.

Building BokehJS with Gulp

Below are the main Gulp commands for development (to be executed from the bokehjs subdirectory). To run these commands, you can either use bokehjs/node_modules/.bin/gulp, install Gulp globally via npm:

npm install -g gulp

or install gulp via conda (recommended):

conda install -c javascript gulp

To generate the compiled and optimized BokehJS libraries with source maps, and deploy them to the build subdirectory:

gulp build

Additionally, gulp build accepts a --build-dir argument to specify where the built resources should be produced:

gulp build --build-dir=/home/bokeh/mybuilddir

For faster development turnaround, you can skip the very slow minification step of the build by issuing:

gulp dev-build

To direct Gulp to automatically watch the source tree for changes and trigger a recompile if any source file changes:

gulp watch

A Gulp build will automatically generate the sources and their associated source maps. With “source mapping” enabled in your browser, you will be able to:

  • debug the original .coffeescript files when using js/bokeh.js
  • debug the compiled non-minified javascript when using js/bokeh.min.js
  • debug the original .less files when using css/bokeh.css or css/bokeh.min.css

in your developer console.

Python Setup

Once you have a working BokehJS build (which you can verify by completing the steps described in Building BokehJS), you can use the setup.py script at the top level of the source checkout to install or develop the full Bokeh library from source.

The setup.py script has two main modes of operation: install and develop.

When python setup.py install is used, Bokeh will be installed in your local site-packages directory. In this mode, any changes to the python source code will not show up until setup.py install is run again.

When python setup.py develop is used, a path file bokeh.pth will be written to your site-packages directory that points to the bokeh subdirectory of your source checkout. Any changes to the python source code will be available immediately without any additional steps.

With either mode, you will be prompted for how to install BokehJS, e.g.:

python setup.py install

Bokeh includes a JavaScript library (BokehJS) that has its own
build process. How would you like to handle BokehJS:

1) build and install fresh BokehJS
2) install last built BokehJS from bokeh/bokehjs/build

Choice?

You may skip this prompt by supplying the appropriate command line option to setup.py:

  • --build_js
  • --install_js

If you have any problems with the steps here, please contact the developers.

Dependencies

In order to build Bokeh from its source, you’ll have to install the project’s python dependencies. If you’re using Conda or pip + virtualenv to setup a development environment, you’ll be able to install these via conda install or pip install for the packages references at Dependencies.

There are additional testing dependencies required to run the unit tests, which include:

  • beautiful-soup
  • colorama
  • pytest
  • pytest-cov
  • pytest-selenium >= 1.0
  • mock
  • websocket-client

Both the build and test dependencies can potentially change between releases and be out of sync with the hosted Bokeh site documentation, so the best way to view the current required packages is the review the meta.yaml file included in the Github repository.


To quickly and easily confirm that your environment contains all of the necessary dependencies to build both the docs and the development version of Bokeh, run the devdeps.py file inside the bokeh/scripts directory.

If any needed packages are missing, you will be given output like this

------------------------------------------------------------------
You are missing the following Dev dependencies:
 *  beautiful-soup

------------------------------------------------------------------
You are missing the following Docs dependencies:
 *  sphinx
 *  pygments

Otherwise, you should see this message

------------------------------------------------------------------
All Dev dependencies installed!  You are good to go!

------------------------------------------------------------------
All Docs dependencies installed!  You are good to go!

Additionally, devdeps.py will check that the bokehjs/node_modules directory exists, which is where npm packages are installed.

If this directory is not found, it will provide instructions on how and where to install npm packages.

Windows Notes

If you build Bokeh on a Windows machine in a Conda environment with either setup.py install or setup.py develop, running bokeh serve will not work correctly. The .exe will not be available within the Conda environment, which means you will use the version available in the base install, if it is available. Instead, you can make sure you use the Python version within the environment by making use of Python’s -m flag, as in the following example:

python -m bokeh serve path\to\<yourapp>.py

Developing Examples

The processes described so far, discussed solely building BokehJS’ components. When using them in the development repository, you must be cautious about which components are picked by Bokeh, especially when working on examples. Failing to do so, may result in you testing wrong version, specifically CDN version of BokehJS.

In the case of statically generated HTML or IPython notebooks, you should set BOKEH_DEV=true in the shell, e.g.:

BOKEH_DEV=true python example.py

This enables the development mode, which uses absolute paths to development (non-minified) BokehJS components, sets logging to debug, makes generated HTML and JSON human-readable, etc. Alternatively you can enable each part of the development mode with a specific shell variable. For example, to configure Bokeh to use relative paths to development resources, issue:

BOKEH_RESOURCES=relative-dev python example.py

For Bokeh server examples, add BOKEH_DEV=true to the server invocation:

BOKEH_DEV=true bokeh serve example-server.py