We welcome contributions to CfdOF. In order to make contributions cohesive with the existing code, as well as administration of the project manageable, when contributing please follow the following contribution guidelines. We have also included some suggestions to make contributing easier, such as development environment setup etc.
Please note the overarching goal of CfdOF is to build simplified and steamlined access to the OpenFOAM® CFD library, as opposed to simply exposing every available function in a GUI environment. So, although contributions are welcomed, we favour usability improvements over rapid expansion of the feature set.
This does not mean that advanced features will not be included - however, some thought and potentially discussion should be applied to your contributions to ensure that ease of use is not compromised, and they may only be accepted once they have been well honed.
It is asked that developers only add functionality or code that is working and can be tested. Dead code, even portions included for possible future functionality, reduces function clarity and increases the maintenance overhead. Our philosophy is 'Do the basics well' and therefore robust operation takes precedence over extended functionality.
The easiest way to develop for CfdOF is to work directly in the FreeCAD module installation directory for CfdOF
($HOME/.FreeCAD/Mod/CfdOF or $HOME/.local/share/FreeCAD/Mod/CfdOF on Linux and %APPDATA%\FreeCAD\Mod\CfdOF on
Windows) as the workbench will be loaded from this location. After installing the workbench via the
Addon Manager, you should be able to use Git for source code management directly from this directory.
A symlink can be used in Linux if you wish to work in a more convenient location.
To contribute code, we suggest forking the CfdOF repository via the Gitlab GUI, and issuing a Merge Request with your bug fix and/or new feature. The repository workflow we use is based on the Github-flow philosophy. Essentially, we ask all developers to submit merge requests for self-contained, tested and working features. Although the process can be frustrating at times, the long-term health of the project depends on being strict on the quality and completeness of code coming in, as well as harmonising it with the existing design philosophy. Please remember that all developers are volunteers with their own interests, and allowing code that is not entirely fit for purpose would place an unfair obligation on others to bring it up to scratch.
That said, there is generally no objection to submission of an incomplete feature in order to expand on it later, as long as it is functional, tested and of good quality as it stands, even if its capabilities are limited.
If you wish to get a first impression or some guidance on a feature you are developing, please feel free to submit a 'Draft' merge request which can be updated later. Alternatively, open an issue for a proposed change to initiate a discussion.
The version number loosely follows Semantic versioning approach in the form MAJOR.MINOR.PATCH.
The major version number is incremented when there is a change which breaks backward compatibility with the file format
(FCStd files). This is avoided wherever possible, and phased conversion periods where an old format is accepted and the
new format written out, are preferred. The minor version number is incremented when there is a new feature in a release,
or a significant enhancement to existing functionality. The patch version is updated when a release contains only
a minor bug fix or fixes. Please increment the version number in package.xml and metadata.txt when
submitting a merge request.
For consistency please follow PEP8
- Use 4 spaces per indentation level (spaces are preferred over tabs).
- An exception is the .ui files describing the GUI templates. For convenience these are indented with 1 space in order to follow the behaviour of the QtDesigner software (see below).
- OpenFOAM template files in the 'Templates' directories should be indented with 4 spaces, and not tabs.
- Limit all lines to a maximum of 120 characters.
- Break lines before binary operators.
- Blank lines
- Surround top-level function and class definitions with two lines.
- Definitions inside a class are surrounded by a single line.
- Imports should usually be on separate lines.
- Comments
- Docstrings always use """ triple double-quotes """
- Block comment starts with a # and a single space and are indented to the same level as that code
- Use inline comments sparingly. They are on the same line as a statement and should be separated by at least two spaces from the statement.
- Avoid trailing whitespaces
- Naming convention
- ClassNames (Camel)
- variable_names_without_capitals (Underscore)
- CONSTANTS_USE_CAPITALS (Uppercase)
- functionsWithCapitals (Although not following PEP8, Camel-case instead of underscore is preferred as it is widely used within FreeCAD)
- __class_attribute (Double leading underscore)
- Python allows both single quotes ('...') and double quotes ("...") for strings. As a convention, please use single quotes for internal string onstants and double quotes for user-facing communication. The rule of thumb is that if a string should be translated, use double quotes. However, this is not a hard-and-fast rule and can be broken for convenience e.g. when quotes are contained in a string.
Unit and regression testing is supported. Where possible, it is asked that new functionality be included in the unit test framework.
In order to run the tests, the following command can be used from the terminal:
FreeCAD -t TestCfdOFAlternatively, from FreeCAD, select the 'Testing framework' workbench, choose the 'Self-test' button, select the 'TestCfdOF' test name and click 'Start'.
At present, there is not much documentation available for CfdOF users. As such, for those contributors who would prefer to help in non-code based ways, we would welcome contributions in terms of video and/or written user guides or tutorials.
For a list of suggested tasks that need attention, please see the Roadmap.
These are simply some suggestions which might help you set up an easy-to-use development environment.
We suggest you use Qt Designer and not Qt Creator - this is a cut down version of Qt Creator, which is the full Qt IDE intended primarily for C++ development. Qt Designer on the other hand is a lightweight GUI design tool, which will write the required XML only which can then be integrated with the Python PySide (PyQT) library used by FreeCAD
- Please ensure that your indent spacing for your GUI template (XML) editing software is set to x1 spaces and not \tab or other indenting, to be consistent with the indenting produced by Qt designer.
- Please note that in some places in the CfdOF GUI, we use a custom input field, GUI::InputField which will need to be included in your set up as a custom widget.
- You should be able to get a prebuilt version of Qt Designer here for Mac and Windows otherwise you can also download a copy using PIP (Package name: pyqt5-tools)
We have found VS Code and PyCharm quick and easy to set up as Python IDEs.
- Whatever IDE you use, the most important consideration is to ensure that your Python interpreter includes the FreeCAD bin and lib paths so that you will have access to the bundled Python libraries distributed (and required) by FreeCAD workbenches
- Please note that at this stage, 3rd party code (i.e. libraries) which can be used by FreeCAD workbenches, are restricted to those distributed with the main FreeCAD installation itself - we cannot at this stage include additional Python libraries with Workbenches.