Installation

CodeIgniter4 can be installed in a number of different ways: manually, using Composer, or even using Git. This section addresses how to use each technique, and explains some of the pros and cons of them.

Once installed, read the next section, running your app.

Note

Before using CodeIgniter 4, make sure that your server meets the requirements.

Manual Installation

Install the framework by downloading the latest version, and extract it to become your project root. Your document root will be the public folder inside here.

Pros:

  • download and run; this is the installation technique closest to that described for CodeIgniter 3.

Cons:

  • upgrading the framework is done by downloading a new copy of the framework, and then following the upgrade directions to merge that with your project (typically replace the system folder and inspect designated application/Config folders for affected changes).

Resulting folder structure:

  • application
  • public
  • system
  • writable

Composer Installation

Install the latest version of the framework with:

> composer create-project codeigniter4/framework PROJECT_ROOT

Pros:

  • simple installation

Cons:

  • upgrading the framework is done by:

    > composer update
    

    You would then need to resolve merge conflicts for any framework changes to application files that you modified for your app.

Resulting folder structure:

  • application
  • public
  • system
  • writable

Codebase Installation

Install the latest version of the codebase by

  • forking the codebase to your github account
  • cloning your forked repository locally

Pros:

  • you get the latest version of the codebase
  • you can propose contributions by creating a feature branch, and then submitting a pull request to the main repository once you have pushed your feature branch to your repository
  • a pre-commit hook is installed for this repo that binds it to the coding-standard repo, and then automatically runs PHP Code Sniffer and fixes any fixable issues whenever you commit.

Cons:

  • you need to add a git remote alias to your project, so you can pull codebase changes:

    > git remote add upstream https://github.com/codeigniter4/CodeIgniter4.git
    
  • upgrading the framework is done by:

    > git checkout develop
    > git pull upstream develop
    > git push origin develop
    

    You would then need to resolve merge conflicts for any framework changes that conflict with modifications you have made.

Resulting folder structure:

  • application
  • public
  • system
  • tests
  • user_guide_src
  • writable

App Starter Installation

Install the latest version of the framework’s app starter with:

> composer create-project codeigniter4/appstarter PROJECT_ROOT

Pros:

  • simple installation

Cons:

  • upgrading the framework is done by:

    > composer update
    

    You would then need to resolve merge conflicts for any framework changes to application files that you modified for your app.

Resulting folder structure:

  • application

  • public

  • writable

  • vendor/codeigniter4/framework

    • application
    • public
    • system

Translations Installation

Install the available localizations to an existing CodeIgniter 4 project with:

> composer require codeigniter4/translations

Update the translations at any time with:

> composer update

When the translations are installed, they are added to the appropriate namespace. See the localization page for guidance.

Resulting folder structure:

...

  • vendor

    • codeigniter4

      • translations

Coding Standards Installation

This is bound and installed automatically as part of the codebase installation.