H2O Flow is a web-based interactive computational environment where you can combine code execution, text, mathematics, plots and rich media to build machine learning workflows.

It is recommended that you clone h2o-3 and h2o-flow under the same parent directory. The following steps will enable you to develop on Flow without having to restart H2O.

1. First, clean up all built files: cd h2o-3 && ./gradlew clean
2. Open up h2o-3 in IDEA, build and launch H2OApp.
3. Run cd h2o-flow && make. You can now access and debug Flow at http://localhost:54321/.
4. After each change to h2o-flow sources, run the same command cd h2o-flow && make to push your changes to the running instance of h2o-3.

The task npm run headless requires installing Phantom JS.

Note: Phantom JS refuses to run on OSX Yosemite, and requires this fix:

brew install upx
upx -d bin/phantomjs