This article shows you how to use Git and Github to code and submit changes to the Joomla CMS. If you are not familiar with Git, you may with to read the tutorial Git for Testers and Trackers first.
The fist step is to set up the remote and local Git repositories. You do this once. Once it is set up, the normal workflow is:
Each of these steps is explained below. Note that you can use Git from the command line, from and IDE such as Eclipse (with the eGit plugin), or from a stand-alone tool, such as TortoiseGit. Here we will use the command line and, where applicable, show the equivalent command in Eclipse eGit.
Github allows you to create your own copy of any public repository, including the Joomla CMS. This is your personal copy of the repository and is called a "fork". To create a fork of the Joomla CMS:
Note that you can only create one fork of any given repository. However, as we will see, you can create as many branches (versions) of your repository as you like.
At this point, you have your own repository on Github.com. Now you need to create a local repository that is a copy (called a "clone") of the Github repository. To do this:
git clone https://github.com/<your Github user name>/joomla-cms.git .For example, if your Github user name is "joomla-coder", the command would be:
git clone https://github.com/joomla-coder/joomla-cms.git .
You can get the URL for the command above from your repository at Github.com as shown below.
Note that the "." dot just tells Git to put the new repository in the current directory. The system will work for a few minutes while it downloads all of the files. When it is finished, you will have a complete set of Joomla files under version control in the current directory.
Now we have our local repository. This has a remote called "origin" that points to our personal fork of Joomla on Github.
In a project like Joomla, many users are submitting bug fixes and features. These changes are committed to the main Joomla CMS repository frequently. It is up to each coder to keep their personal repositories up to date with these changes. Fortunately, as we will see, this is easy to do.
The last step in the setup is to create a second remote called "upstream" that points to the main Joomla CMS repository. We will use this remote to pull changes that others make to the main Joomla repository so we can keep our personal repositories up to date.
To create a remote called "upstream" that points to the main CMS repository, enter this command:
git remote add upstream https://github.com/joomla-coder/joomla-cms.git
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At this point, you have your personal remote repository (created by "forking" the Joomla CMS project) and your personal local repository (created with CLI or Eclipse). Now you are ready to code patches and features.
Now that we have done our one-time setup, we are ready to start our normal workflow. This is outlined below.
Let's say you are ready to start working on a new bug fix or a new feature. Here are the steps you would normally follow.
Each of these steps is explained in more detail below.
You need to keep your repositories up to date with changes made by others in the main CMS repository. It's easy to do, and here are the steps. These are done more easily with the CLI than with Eclipse.
IMPORTANT NOTE: Make sure you never commit your own code changes to the master branch. If you do, you won't be able to keep it synchronized with the master branch on the main CMS repository.
git checkout master). If you aren't sure, you can use the command
git statusto see what branch you are on.
git pull upstream master. You should get a message showing the changes, similar to this:
$ git pull upstream master From https://github.com/joomla/joomla-cms * branch master -> FETCH_HEAD Updating 76feee8..294c62c Fast-forward installation/CHANGELOG | 3 +++ installation/language/fr-FR/fr-FR.ini | 2 +- 2 files changed, 4 insertions(+), 1 deletion(-) Mark@MARK2009 /c/xampp/htdocs/joomla-coder/joomla-cms (master)
$ git pull upstream master From https://github.com/joomla/joomla-cms * branch master -> FETCH_HEAD Already up-to-date.
git push origin master. You should see a message like this:
$ git push origin master To https://github.com/joomla-coder/joomla-cms.git 76feee8..294c62c master -> master
NOTE: If you haven't stored your user name and password, you will be prompted for them after you enter the push command. See below for how to store your credentials so you don't have to type them each time.
At this point, your master branches on your local and Github repositories are up to date with the main CMS repository. Now, when you create a new branch, it will start at this point and be based on the latest code.
In Git, the best practice is to use a branch for each bug fix or feature. (In fact, experienced Git users will often create more than one branch for an individual project, perhaps trying different approaches to the problem.) It is super easy to create, delete, and even combine branches. Use a naming convention that allows you to keep track. For example, you could incorporate the tracker issue number into the branch name (for example, "php-notice-12345").
When you create a new branch, it starts from the branch you are currently on. For this reason, you will normally want to make sure you are in your master branch when creating a new one.
git create xxx where "xxx" is the new branch name. Note: If you already have a branch you are working on, use the command:
git checkout xxx.
Finally, we are to the fun part! Here we are actually coding and testing our feature or bug fix. The normal workflow is as follows:
Here are the commands to commit your work to your branch. Make sure you are in the right branch before committing! (Use
git status to check.)
git commit -m "My commit message" -a
git reset --hard
git clean -d -f
git commit --amend
In the previous workflow, we created the branch and committed changes to our local repository. If we want others to be able to see the branch or to create a pull request, we need to push the branch to our personal repository on Github.
To push a branch to your personal Github repository:
git push origin xxx (where "xxx" is the name of your branch).
As discussed earlier, the main CMS repository on Github is being changed frequently. It is possible that one or more of these changes could conflict with (or otherwise affect) our work. For this reason, it is very important that we keep our repositories up to date. Otherwise, our patch files and pull requests may not work.