Development

Overview

GnuCash is written principally in C. A Guile interpreter is built in and parts of Gnucash--principally reports, but also parts of the user configuration, file import, and other small parts--are in Scheme. The C API is wrapped for Guile access with SWIG; Python wrappers can be created with a configure option.

The GUI is built with GTK+ version 2.24.

The build system is GNU autotools. Understanding this complex system isn't generally necessary for fixing simple bugs, but more complex work will. Here's an excellent tutorial.

We use DOxygen to document the sources, including the C API. Details about our use are on the Doxygen wiki page. The Help Manual and Concepts Guide are formatted using DocBook, an SGML markup language which enables us to generate them in several formats. Note that these documents have a separate repository.

The development team's plans for future work are outlined in the Roadmap, and some other suggested enhancements may be found in the WishList as well as the many enhancements requested in Bugzilla.

Object Orientation

Most of the code is written in an object-oriented style. Some of it uses GObject, some uses a home-grown GObject-like system called QofObject, and some just does what GObject does in straight C. Understanding how to use that is an important skill to developing for GnuCash. The next development cycle will include migrating those parts of Gnucash other than the GUI to C++; see our C++ page for details and resources. We are deferring updating the GUI either to Gtk+-3 or some other framework for at least another development cycle.

Preliminaries

Please subscribe to the Mailing Lists and introduce yourself to the development team. Some of the team also hang out on IRC so you can interact more directly.

Read the two files HACKING and README.svn

Look through the API documentation.

Getting Sources and Building

We are in the last stage of converting source code version control from Subversion to Git, which we intend to complete shortly after releasing GnuCash version 2.6 at the end of 2013. New contributors should follow the git instructions for cloning the repository and preparing patches. Any current developers still using subversion should switch to git for most of their work as soon as possible in order to be ready for the final conversion.

Build instructions for various platforms are described or linked at Building.

Coding Guidelines

• Please try to develop according to Test Driven Development principles, following our Testing guidelines.
• The coding style was last discussed on the gnucash-devel ML.
• If your code will contain textual output for the user, have a look at Translation: Tips for Developers.
• Be sure that make check passes before preparing your patch or pushing your commit.

Documentation

If your code adds or changes some functionality, do not forget the documentation.

• Make sure that global (i.e. not static) functions are documented with Doxygen-formatted comments.
• Try to keep the README files and that in src/doc up to date.
• Update the relevant sections in Help Manual and the Concept Guide.

Submitting Patches

Once you have your changes written and well tested—make check will run a bunch of tests—you'll want to submit it so that someone with commit privilege can add it to the official sources. First, make a patch.

If there's already a bug about it in Bugzilla, just attach the patch to the bug. Be sure to check the "patch" checkbox on the attachment form. If there isn't a bug already (be sure to search!), it really works best if you create a new one to attach your patch to.

• Describe the problem or improvement that your patch addresses in the initial comment.
• Open the bug before you make your patch so that you can include the bug number in the commit message.

If there isn't a bug already and the patch is trivial, you can send it to the gnucash-devel mailing list (though we really do prefer patches to go to Bugzilla). Please attach the patch to the email, don't inline it in the message, even if you used git format-patch and it made a pretty email for you.

Tools

Text editors / IDE:

• Most developers seem to have used Emacs as IDE.
• Additionally there are some experiences with Eclipse.
• Some are using QtCreator.

Some may be interested in our experiments with CMake and Qt, Cutecash.