Contribution Workflow

Much of the workflow for contributing to CodeIgniter (or any project) involves understanding how Git is used to manage a shared repository and contributions to it. Examples below use the Git bash shell, to be as platform neutral as possible. Your IDE may make some of these easier.

Some conventions used below, which you will need to provide appropriate values for when you try these:

ALL_PROJECTS    // folder location with all your projects in subfolders, eg /lampp/htdocs
YOUR_PROJECT    // folder containing the project you are working on, inside ALL_PROJECTS
ORIGIN_URL      // the cloning URL for your repository fork
UPSTREAM_URL    // the cloning URL for the CodeIgniter4 repository


CodeIgniter uses the Git-Flow branching model, which requires all pull requests to be sent to the "develop" branch. This is where the next planned version will be developed. The "master" branch will always contain the latest stable version and is kept clean so a "hotfix" (e.g: an emergency security patch) can be applied to master to create a new version, without worrying about other features holding it up. For this reason all commits need to be made to "develop" and any sent to "master" will be closed automatically. If you have multiple changes to submit, please place each change into their own branch on your fork.

One thing at a time: a pull request should only contain one change. That does not mean only one commit, but one change - however many commits it took. The reason for this is that if you change X and Y but send a pull request for both at the same time, we might really want X but disagree with Y, meaning we cannot merge the request. Using the Git-Flow branching model you can create new branches for both of these features and send two requests.


You work with a fork of the CodeIgniter4 repository. This is a copy of our repository, in your github account. You can make changes to your forked repository, while you cannot do the same with the shared one - you have to submit pull requests to it instead.

Creating a fork is done through the Github website. Navigate to our repository, click the Fork button in the top-right of the page, and choose which account or organization of yours should contain that fork.


You could work on your repository using Github's web interface, but that is awkward. Most developers will clone their repository to their local system, and work with it there.

On Github, navigate to your forked repository, click Clone or download, and copy the cloning URL shown. We will refer to this as ORIGIN_URL.

Clone your repository, leaving a local folder for you to work with:

git clone ORIGIN_URL


Within your local repository, Git will have created an alias, origin, for the Github repository it is bound to. You want to create an alias for the shared repository, so that you can "synch" the two, making sure that your repository includes any other contributions that have been merged by us into the shared repo:

git remote add upstream UPSTREAM_URL

Then synchronizing is done by pulling from us and pushing to you. This is normally done locally, so that you can resolve any merge conflicts. For instance, to synchronize develop branches:

git checkout develop
git pull upstream develop
git push origin develop

You might get merge conflicts when you pull from upstream. It is your responsibility to resolve those locally, so that you can continue collaborating with the shared repository. Basically, the shared repository is updated in the order that contributions are merged into it, not in the order that they might have been submitted. If two PRs update the same piece of code, then the first one to be merged will take precedence, even if it causes problems for other contributions.

It is a good idea to synchronize repositories when the shared one changes.

Branching Revisited

The top of this page talked about the master and develop branches. The best practice for your work is to create a feature branch locally, to hold a group of related changes (source, unit testing, documentation, change log, etc). This local branch should be named appropriately, for instance "fix/problem123" or "new/mind-reader".

For instance, make sure you are in the develop branch, and create a new feature branch, based on develop, for a new feature you are creating:

git checkout develop
git checkout -b new/mind-reader

Saving changes only updates your local working area.


Your local changes need to be committed to save them in your local repository. This is where contribution signing comes in.

You can have as many commits in a branch as you need to "get it right". For instance, to commit your work from a debugging session:

git add .
git commit -S -m "Find and fix the broken reference problem"

Just make sure that your commits in a feature branch are all related.

If you are working on two features at a time, then you will want to switch between them to keep the contributions separate. For instance:

git checkout new/mind-reader
// work away
git add .
git commit -S -m "Added adapter for abc"
git checkout fix/issue-123
// work away
git add .
git commit -S -m "Fixed problem in DEF\Something"
git checkout develop

The last checkout makes sure that you end up in your develop branch as a starting point for your next session working with your repository. This is a good practice, as it is not always obvious which branch you are working in.

Pushing Your Branch

At some point, you will decide that your feature branch is complete, or that it could benefit from a review by fellow developers.


Remember to synch your local repo with the shared one before pushing! It is a lot easier to resolve conflicts at this stage.

Synchronize your repository:

git checkout develop
git pull upstream develop
git push origin develop

Bring your feature branch up to date:

git checkout new/mind-reader
git merge develop

And finally push your local branch to your github repository:

git push origin new/mind-reader

Pull Requests

On Github, you propose your changes one feature branch at a time, by switching to the branch you wish to contribute, and then clicking on "New pull request".

Make sure the pull request is for the shared develop branch, or it may be rejected.

Make sure that the PR title is helpful for the maintainers and other developers. Add any comments appropriate, for instance asking for review.


If you do not provide a title for your PR, the odds of it being summarily rejected rise astronomically.

When your PR is submitted, a continuous integration task will be triggered, running all the unit tests as well as any other checking we have configured for it. If the unit tests fail, or if there are merge conflicts, your PR will not be mergeable until fixed.

Fix such changes locally, commit them properly, and then push your branch again. That will update the PR automatically, and re-run the CI tests. You don't need to raise a new PR.

If your PR does not follow our contribution guidelines, or is incomplete, the codebase maintainers will comment on it, pointing out what needs fixing.


If your PR is accepted and merged into the shared repository, you can delete that branch in your github repository as well as locally.