View source for Development

[[Category:Development]]
= Overview =
GnuCash is written principally in [{{URL:wp}}C_(programming_language) C]. A [{{URL:guile}} 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 [{{URL:swig}} SWIG]; Python wrappers can be created with a configure option. 

The GUI is built with [{{URL:GTK}} GTK+] version {{GTK_Version}}.

We're supporting the [{{URL:cmake}} CMake] build system. Understanding this complex system isn't generally necessary for fixing simple bugs, but more complex work will. Here's a [{{URL:cmake}}getting-started/ Getting Started with CMake] and a [{{URL:cmake-wiki}} wiki].

;Documentation:
:;For Developers: We use [{{URL:wp}}Doxygen Doxygen] to document the sources, including the C API. Details about our use are on the [[Doxygen]] wiki page.
:;For Users: The ''GnuCash Manual'' and ''Tutorial and Concepts Guide'' are formatted using [{{URL:wp}}DocBook DocBook], a semantic markup language which enables us to publish them in several formats. Note that these documents have a separate [{{URL:git}}gnucash-docs repository]. The processing is explained in [[Documentation Improvement]].

== Object Orientation ==
Most of the code is written in an object-oriented style. Some of it uses [{{URL:wp}}GObject 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 [{{URL:C++}} C++]; see our [[C++]] page for details and resources. We have updated the GUI to Gtk+-3 in the 2.7 series.

= What We Need Help On =
* Patches to fix [[Bugzilla|bugs]] are always a appreciated. It's an excellent way to get familiar with the code base and to introduce yourself to the team.
* If you prefer to dive in at the deep end, have a look at the development team's [[Roadmap|long-term plans]].
= 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 [{{URL:git}}blob/stable/HACKING HACKING] and [{{URL:git}}blob/stable/README.git README.git]

Look through the [{{URL:docs:API}} API documentation].

= Getting Sources and Building =
You can follow the git [[Git|instructions]] for cloning the repository and preparing patches.

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

= Coding Guidelines =
* Please try to develop according to [{{URL:wp}}Test-driven_development Test Driven Development] principles, following our [[Testing]] guidelines.
* Please follow our [[CodingStandard| coding style]].
* If your code will contain '''textual output for the user''', have a look at [[Translation#Tips_for_Developers | Translation: Tips for Developers]] and configuration [[Settings Wording]].
* Be sure that <tt>make check</tt> 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.
* [[Documentation Improvement|Update]] the relevant sections in the ''Manual'' and the [[Concept Guide]].

= Submitting Patches =

Once you have your changes written and well tested&mdash;<tt>make check</tt> will run a bunch of tests&mdash;you'll want to submit it so that someone with commit privilege can add it to the official sources. There are two ways we accept code:
 
# [[Git#Pull_Requests|Github pull requests]]: This is the preferred method if the change is non-trivial.
#* If there is already a [[Bugzilla|bug report]] on the matter be sure to include a link to the bug in the pull request and comment on the bug with a link to the pull request.
# Attach a patch to a [[Bugzilla|bug report]]:
:* [[Git#Patches|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!), you'll need to 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 commit your changes so that you can include the bug number in the commit message.

= Tools =

Text editors / IDE:
* Most developers seem to have used [[Emacs]] as IDE.
* Additionally there are some experiences with [[Eclipse]].
* Still to be documented: [[KDevelop]].
* Some are using [{{URL:wp}}QtCreator QtCreator].

For the GTK GUI:
* [{{URL:Gnome|glade}} Glade]

Some may be interested in our experiments with [[CMake]] and [{{URL:wp}}Qt_(software) Qt]: [[Cutecash]].

= See also =

An [{{URL:mail archive|devel}}2004-June/011547.html informative mail] from the archives.

;GnuCash design and developer's reference: [{{URL:docs:API}} current bugfix] and
: —after creation— [{{URL:docs:API|FUTURE}} future features] branch.

[{{URL:guile-manual}}Programming-in-Scheme.html Scheme programming manual]

[[C API]]