CI-Upgrader will help you to upgrade your CodeIgniter 3 project to CodeIgniter 4.

To do this, CI-Upgrader transfers a lot of CI3 files and code into CI4 Syntax, but takes also usage of the ci3-to-4-upgrader-helper by Kenji Suzuki. Kenjis upgrader-helper provides interfaces for common use cases in CodeIgniter, to make them compatible and executable in CI4.

This tool is most suitable for developers who want to perform a quick upgrade of there CI3 project with as little work as possible. If you want to extend your project after the upgrade, you have the option to use CI3 and CI4 syntax in the most parts of your code.

On the other hand, you have also the opportunity to remove Kenji Suzukis upgrade-helper from selected files or even from the whole project. In this case, you have to transfer the affected code manually into CI4 syntax. For this it is recommended to take a look at the Upgrade Guide of the official documentation, which will be of great help in this regard.

(This tool was created as a part of my bachelor thesis at University of Trier)

These following tasks are carried out automatically by CI-Upgrader:

• Installation
  • Installs a new CI4 project in the same directory as the CI3 project
  • The installation includes also phpunit and kenjis upgrade-helper
• Copy Files
  • Copies all relevant directories and files from the old CI3 to the new CI4 project
• Edit Files
  • Convert CI3 files/settings into CI4 (Config, Languages, Migrations, Routes)
  • Use Kenji Suzukis upgrade-helper to make CI3 code compatible (Controllers, Models, Libraries)
• Create UpgradeLog
  • This created file contains all informations about the upgrade process and all tasks the CI-Upgrader has executed

However CI-Upgrader is not able to transfer all of your code into CodeIgniter 4 without errors. So some manually adjustment has to be done afterwards. Thats because there are a lot of new things in CI4, like different application structure, syntax and namespaces. Also CodeIgniter projects can be very individual, specially with own created Libraries, Classes and Functions.

For more informations about CI-Upgrader and the adjustment that have to be done after the upgrade, check out User Guide.

• Executable CodeIgniter 3 project
• Windows system (Linux and macOs are not supported)
• Composer installed
• JRE 1.6.6 (or later)

Here you can see an example of a simple CodeIgniter 3 project, which was transferred to CodeIgniter 4 with CI-Upgrader.

• CodeIgniter 3: test_ci3
• CodeIgniter 4: test_ci3_upgrade_to_ci4

This repository contains the source code of CI-Upgrader, so fell free to take it. You can work with it, develop your own tool or try to improve CI-Upgrader.

Pull Requests are very welcome.