Principles and code style (draft)

Defining (architectural) principles and code style keeps the code base consistent and manages expectations for contributions.


On the backend, we use the Django framework and follow the project structure of having apps within the project.

  • Django apps contains models, views and API definitions. They group a logical part of the greater project which is loosely coupled to other apps.

    Tests are in the django app package. Split tests in logical modules, and try to avoid complex nesting structures.

  • All apps must go in the src/openzaak directory, which namespaces all the Open Zaak code in the openzaak package. This prevents name conflicts with third party applications.

  • Application names should always be in plural form.

  • Components from the API standard go in openzaak.components.<component>.

  • Settings go in openzaak.conf, which is split according to deploy environment:

    • dev

    • ci (Travis)

    • staging

    • production

    • docker

    Settings must always be defined in the openzaak.conf.includes.base or openzaak.conf.includes.api with sane defaults.

  • Global runtime Open Zaak configuration (database backed) should go in the openzaak.config app.

  • Generic tools that are used by specific apps should be a openzaak sub-package, or possibly go in openzaak.utils.

  • Integration with other, third-party services/interfaces should go in a openzaak.contrib package. This is currently (!) not the case yet.

  • Code style is enforced in CI with black. When Black is not conclusive, stick to PEP 8.

  • Imports are sorted using isort.


  • Javascript goes in the src/openzaak/js directory

  • If possible, stick to Vanilla JS

  • (Highly) dynamic interfaces are built using React. Components should:

    • go in src/openzaak/js/components

    • preferably use functional components with react hooks

    • aim to be prop-driven and keep as little local state as possible

    • be properly prop-type annotated

    • have default values for optional props

  • Code should be linted and quality checked using ESLint, with the AirBnB preset

  • Browser support: latest and latest -1 version of the major browsers