# Hacking

Want to fix a bug in Pootle? Want to change the behaviour of an existing feature or add new ones? This section is all about hacking on Pootle, so if you are interested on the topic, keep reading.

## Before doing anything

Before starting any actual work on the source code, make sure that:

- There is nobody working on the bug you are trying to fix. See the existing bug reports and the existing pull requests. In the situation where somebody else is working on a fix, you can always offer your help.
- If you plan to develop a new feature and want to include it upstream, please first discuss it with the developers on IRC or in the translate-pootle mailing list so that it doesn’t interfere in current development plans. Also note that adding new features is relatively easy, but keeping them updated is harder.

## Setting up the development environment

The minimum software packages you need for setting up a development environment include git and a Python interpreter along with the pip installer. Consult the specifics for your operating system in order to get each package installed successfully.

Once you have the minimums in place, you will need to install Pootle’s dependencies, which come in shape of Python packages. Instead of installing them system-wide, we recommend using virtualenv (and virtualenvwrapper for easing the management of multiple virtualenvs). This way you can install all the dependencies at specific versions without interfering with system-wide packages. You can test on different Python/Django versions in parallel as well.

For the impatients:

    $ sudo pip install virtualenvwrapper
    $ mkvirtualenv <env-name>
    (env-name) $ git clone https://github.com/translate/pootle.git
    (env-name) $ cd pootle
    (env-name) $ pip install -r requirements/dev.txt
    (env-name) $ python manage.py runserver

That will leave you with a Pootle development server up and running ready to start hacking!

Note

If you have a GitHub account, fork the main translate/pootle repository and replace the repository URL by your own fork.

### Detailed setup

These are essentially the same steps as above but with further details and explanations.

For installing the dependencies in an isolated environment, we will use virtualenv — more specifically virtualenvwrapper, which eases the process of managing and switching between multiple virtual environments. Installing virtualenwrapper will pull in virtualenv as a dependency.

    $ sudo pip install virtualenvwrapper

virtualenvwrapper will need to be configured in order to specify where to store the created environments.

    $ export WORKON_HOME=~/envs
    $ mkdir -p $WORKON_HOME
    $ source /usr/local/bin/virtualenvwrapper.sh

Note

You may want to add the above-mentioned commands in your `.bashrc` file (or whatever file your shell uses for initializing user customizations).

Now the commands provided virtualenv and virtualenvwrapper are available, so we can start creating our virtual environment.

    $ mkvirtualenv <env-name>

Replace `<env-name>` with a meaningful name that describes the environment you are creating. `mkvirtualenv` accepts any options `virtualenv` accepts. We could for example specify to use the Python 2.6 interpreter by passing the `-p python2.6` option.

After running `mkvirtualenv`, the newly created environment is activated. To activate and deactivate virtual environments simply run `workon <env-name>` and `deactivate`.

Time to clone Pootle’s source code repository. The main repository lives under translate/pootle in GitHub. If you have a GitHub account, the best idea is to fork the main repository and to clone your own fork for hacking. Once you know which way you want to continue forward, just move to a directory where you want to keep the development files and run `git clone` by passing the repository’s URL.

    (env-name) $ git clone https://github.com/translate/pootle.git

This will create a directory named pootle where you will find all the files that constitute Pootle’s source code.

Before running the development server, it’s necessary to install the software dependencies/requirements by using pip. For this matter there are some pip requirements files within the requirements directory. We will install the requirements defined in requirements/dev.txt, which apart from the minimum will pull in some extras that will ease the development process.

    (env-name) $ cd pootle
    (env-name) $ pip install -r requirements/dev.txt

Note

Some dependencies might need to build or compile source code in languages other than Python. You may need to install extra packages on your system in order to complete the build process and the installation of the required packages.

With all the dependencies installed within the virtual environment, Pootle is almost ready to run. In development environments you will want to use settings that vastly differ from those used in production environments.

For that purpose there is a sample configuration file with settings adapted for development scenarios, pootle/settings/90-dev-local.conf.sample. Copy this file and rename it by removing the .sample extension and you’re good to go.

Note

To learn more about how settings work in Pootle head over the Settings section in the documentation.

Finally, just run the development server.

    (env-name) $ python manage.py runserver

Now you can reach the development server in your browser. On your first visit, Pootle will create the database schema and will calculate stats, which might take a while on the first time. Alternatively, you can choose to run `python manage.py initdb` which will do the same but in a shell environment.

Once all is done, you can start the development server anytime by enabling the virtual environment and running the `manage.py runserver` command.

Happy hacking!!

## Workflow

Any time you want to fix a bug or work on a new feature, create a new local branch:

    $ git checkout -b <my_new_branch>

Then safely work there, create the needed commits and once the work is ready for being incorporated upstream, either:

- Push the changes to your own GitHub fork and send us a pull request, or
- Create a patch against the `HEAD` of the `master` branch using `git diff` or `git format-patch` and attach it to the affecting bug.

## Commits

When creating commits take into account the following:

What to commit
  As far as possible, try to commit individual changes in individual commits. Where different changes depend on each other, but are related to different parts of a problem / solution, try to commit then in quick succession.
Commit messages

  Begin the commit message with a single short (less than 50 character) line summarizing the change, followed by a blank line and then a more thorough description.

  If your change fixes a bug in Bugzilla, mention the bug number, and mention the commit sha1 in the bug. If you are reverting a previous commit, mention the sha1 revision that is being reverted.