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.
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.
The BokehJS build process is handled by Grunt, which in turn depends on
Node.js. Grunt 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.
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 Binstar:
$ conda install -c bokeh nodejs
Alternatively, on Ubuntu you can use apt-get
:
$ apt-get install npm node
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 command in the bokehjs
subdirectory:
$ npm install
This command will install the necessary packages into the node_modules
subdirectory (and list them as devDependencies
in package.json
).
At this point you can typically use the setup.py
script at the top level
of the source chekcout to manage building and installing BokehJS as part of
the complete Bokeh library (see Python Setup).
However, if you are using BokehJS as a standalone JavaScript library, then the instructions below describe the process to iteratively build BokehJS with Grunt for development purposes.
If you want to be able to run the commands below, you can either use
bokehjs/node_modules/.bin/grunt
or globally install
the grunt command line interface:
$ npm install -g grunt-cli
There are three main Grunt commands for development (to be executed from the
bokehjs
subdirectory):
$ grunt deploy
This will generate the compiled and optimized BokehJS libraries, and deploy
them to the build
subdirectory.
$ grunt build
This will build the BokehJS sources without concatenating and optimizing into standalone libraries. At this point BokehJS can be be as an AMD module.
$ grunt watch
This directs Grunt to automatically watch the source tree for changes and
trigger a recompile of individual files as they change. This is especially
useful together with the --splitjs
mode of the Bokeh server to afford a
more rapid development cycle.
Warning
The sbt
build system is experimental and not integrated with
setup.py
, so it should be used with caution.
As an alternative to Grunt, you can use SBT to build BokehJS. To start, run the command:
$ ./sbt
in the top level directory. This will download sbt
(and its dependencies)
itself, and configure the build system.
There are two main commands available: build
and deploy
. The build
command compiles CoffeeScript, Less and Eco sources, and copies other resources
to the build directory. The deploy
command does the same and additionally
generates optimized and minified bokeh.js
and bokeh.css
outputs.
You may also run specific subtasks, e.g. compile
to compile CoffeeScript,
Less and Eco sources, but not copy resources. You can also prefix any command
with ~
, which enables incremental compilation. For example, issuing ~less
will watch *.less
sources and compile only the subset of files that changed.
To stop watching sources, press ENTER. Pressing Ctrl+C will terminate sbt
.
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 (see Contact).
If you are working within a Conda environment, you will need to make sure you
have the python requirements installed. You can install these via conda
install
or pip install
for the packages referenced at
Dependencies.
Testing dependencies include the following additional libraries:
If you build Bokeh on a Windows machine in a Conda environment with either
setup.py install
or setup.py develop
, running bokeh-server
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 version
within the environment by explicitly running the bokeh-server python script
in the root of the bokeh repository, similar to the following example:
python bokeh-server --script path\to\<yourapp>.py
The processes described about result in building and using a full bokeh.js
library. This could be considered “production” mode. It is also possible to
run Bokeh code in a mode that utilizes require.js
to serve up individual
JavaScript modules separately. If this is done, then changes to BokehJS
can be incrementally compiled (e.g. by running grunt watch
in the
bokehjs
directory), and the development iteration cycle shortened
considerably.
For static examples, you can use the BOKEH_RESOURCES
environement variable
to indicate that BokehJS should be loaded from individual sources:
$ BOKEH_RESOURCES=relative-dev python example.py
For Bokeh server examples, simply add the --dev
command line flag to the
server invocation:
$ bokeh-server --dev
$ python example-server.py