Submitting patches

We’re always grateful for patches to Django’s code. Indeed, bug reports with associated patches will get fixed far more quickly than those without patches.

“Claiming” tickets

In an open-source project with hundreds of contributors around the world, it’s important to manage communication efficiently so that work doesn’t get duplicated and contributors can be as effective as possible. Hence, our policy is for contributors to “claim” tickets in order to let other developers know that a particular bug or feature is being worked on.

If you have identified a contribution you want to make and you’re capable of fixing it (as measured by your coding ability, knowledge of Django internals and time availability), claim it by following these steps:

  • Create an account to use in our ticket system. If you have an account but have forgotten your password, you can reset it using the password reset page.
  • If a ticket for this issue doesn’t exist yet, create one in our ticket tracker.
  • If a ticket for this issue already exists, make sure nobody else has claimed it. To do this, look at the “Assigned to” section of the ticket. If it’s assigned to “nobody,” then it’s available to be claimed. Otherwise, somebody else is working on this ticket, and you either find another bug/feature to work on, or contact the developer working on the ticket to offer your help.
  • Log into your account, if you haven’t already, by clicking “Login” in the upper right of the ticket page.
  • Claim the ticket:
    1. click the “accept” radio button under “Action” near the bottom of the page,
    2. then click “Submit changes.”

Ticket claimers’ responsibility

Once you’ve claimed a ticket, you have a responsibility to work on that ticket in a reasonably timely fashion. If you don’t have time to work on it, either unclaim it or don’t claim it in the first place!

If there’s no sign of progress on a particular claimed ticket for a week or two, another developer may ask you to relinquish the ticket claim so that it’s no longer monopolized and somebody else can claim it.

If you’ve claimed a ticket and it’s taking a long time (days or weeks) to code, keep everybody updated by posting comments on the ticket. If you don’t provide regular updates, and you don’t respond to a request for a progress report, your claim on the ticket may be revoked. As always, more communication is better than less communication!

Which tickets should be claimed?

Of course, going through the steps of claiming tickets is overkill in some cases. In the case of small changes, such as typos in the documentation or small bugs that will only take a few minutes to fix, you don’t need to jump through the hoops of claiming tickets. Just submit your patch and be done with it.

Patch style

  • Make sure your code matches our Coding style.

  • Submit patches in the format returned by the svn diff command. An exception is for code changes that are described more clearly in plain English than in code. Indentation is the most common example; it’s hard to read patches when the only difference in code is that it’s indented.

    Patches in git diff format are also acceptable.

  • When creating patches, always run svn diff from the top-level trunk directory – i.e. the one that contains django, docs, tests, AUTHORS, etc. This makes it easy for other people to apply your patches.

  • Attach patches to a ticket in the ticket tracker, using the “attach file” button. Please don’t put the patch in the ticket description or comment unless it’s a single line patch.

  • Name the patch file with a .diff extension; this will let the ticket tracker apply correct syntax highlighting, which is quite helpful.

  • Check the “Has patch” box on the ticket details. This will make it obvious that the ticket includes a patch, and it will add the ticket to the list of tickets with patches.

  • The code required to fix a problem or add a feature is an essential part of a patch, but it is not the only part. A good patch should also include a regression test to validate the behavior that has been fixed and to prevent the problem from arising again. Also, if some tickets are relevant to the code that you’ve written, mention the ticket numbers in some comments in the test so that one can easily trace back the relevant discussions after your patch gets committed and the tickets get closed.

  • If the code associated with a patch adds a new feature, or modifies behavior of an existing feature, the patch should also contain documentation.

Non-trivial patches

A “non-trivial” patch is one that is more than a simple bug fix. It’s a patch that introduces Django functionality and makes some sort of design decision.

If you provide a non-trivial patch, include evidence that alternatives have been discussed on django-developers. If you’re not sure whether your patch should be considered non-trivial, just ask.

Javascript patches

Django’s admin system leverages the jQuery framework to increase the capabilities of the admin interface. In conjunction, there is an emphasis on admin javascript performance and minimizing overall admin media file size. Serving compressed or “minified” versions of javascript files is considered best practice in this regard.

To that end, patches for javascript files should include both the original code for future development (e.g. foo.js), and a compressed version for production use (e.g. foo.min.js). Any links to the file in the codebase should point to the compressed version.

To simplify the process of providing optimized javascript code, Django includes a handy script which should be used to create a “minified” version. This script is located at django/contrib/admin/static/js/compress.py.

Behind the scenes, compress.py is a front-end for Google’s Closure Compiler which is written in Java. However, the Closure Compiler library is not bundled with Django directly, so those wishing to contribute complete javascript patches will need to download and install the library independently.

The Closure Compiler library requires Java version 6 or higher (Java 1.6 or higher on Mac OS X). Note that Mac OS X 10.5 and earlier did not ship with Java 1.6 by default, so it may be necessary to upgrade your Java installation before the tool will be functional. Also note that even after upgrading Java, the default /usr/bin/java command may remain linked to the previous Java binary, so relinking that command may be necessary as well.

Please don’t forget to run compress.py and include the diff of the minified scripts when submitting patches for Django’s javascript.