Composer Installation

Composer can be used in two ways to install CodeIgniter4 on your system.

Important

CodeIgniter4 requires Composer 2.0.14 or later.

Note

If you are not familiar with Composer, we recommend you read Basic usage first.

The first technique describes creating a skeleton project (app starter) using CodeIgniter4, that you would then use as the base for a new webapp. The second technique described below lets you add CodeIgniter4 to an existing webapp,

Note

If you are using a Git repository to store your code, or for collaboration with others, then the vendor folder would normally be “git ignored”. In such a case, you will need to do a composer install (or composer update if you want to update all Composer dependencies) when you clone the repository to a new system.

App Starter 

The CodeIgniter 4 app starter repository holds a skeleton application, with a composer dependency on the latest released version of the framework.

This installation technique would suit a developer who wishes to start a new CodeIgniter4 based project.

Installation 

In the folder above your project root:

composer create-project codeigniter4/appstarter project-root

The command above will create a project-root folder.

If you omit the “project-root” argument, the command will create an “appstarter” folder, which can be renamed as appropriate.

Note

Before v4.4.0, CodeIgniter autoloader did not allow special characters that are illegal in filenames on certain operating systems. The symbols that can be used are /, _, ., :, \ and space. So if you installed CodeIgniter under the folder that contains the special characters like (, ), etc., CodeIgniter didn’t work. Since v4.4.0, this restriction has been removed.

Important

When you deploy to your production server, don’t forget to run the following command:

composer install --no-dev

The above command will remove the Composer packages only for development that are not needed in the production environment. This will greatly reduce the vendor folder size.

Installing Previous Versions

For example, you may want to install v4.4.8 after v4.5.0 has been released.

In that case, specify the version in the command:

composer create-project codeigniter4/appstarter:4.4.8 project-root

Then, open composer.json in your project root folder, and specify the framework version:

"require": {
    ...
    "codeigniter4/framework": "4.4.8"
},

Then, run the composer update command.

Note

When you use a fixed version number like "codeigniter4/framework": "4.4.8" in your composer.json, composer update command will not update the framework to the latest version. See Writing Version Constraints for how to specify the version.

Initial Configuration 

After installation, a few initial configurations are required. See Initial Configuration for the details.

Upgrading 

Whenever there is a new release, then from the command line in your project root:

composer update

Read the upgrade instructions and change log, and check Breaking Changes and Enhancements.

Upgrading to a Specified Version

For example, you may want to upgrade from v4.4.7 to v4.4.8 after v4.5.0 has been released.

In that case, open composer.json in your project root folder, and specify the framework version:

"require": {
    ...
    "codeigniter4/framework": "4.4.8"
},

Then, run the composer update command.

Note

When you use a fixed version number like "codeigniter4/framework": "4.4.8" in your composer.json, composer update command will not update the framework to the latest version. See Writing Version Constraints for how to specify the version.

Pros 

Simple installation; easy to update.

Cons 

You still need to check for file changes in the project space (root, app, public, writable) and merge them after updating.

Note

There are some third-party CodeIgniter modules available to assist with merging changes to the project space: Explore on Packagist.

Structure 

Folders in your project after set up:

app, public, tests, writable
vendor/codeigniter4/framework/system

Latest Dev 

The App Starter repo comes with a builds scripts to switch Composer sources between the current stable release and the latest development branch of the framework. Use this script for a developer who is willing to live with the latest unreleased changes, which may be unstable.

The development user guide is accessible online. Note that this differs from the released user guide, and will pertain to the develop branch explicitly.

Update for Latest Dev

In your project root:

php builds development

The command above will update composer.json to point to the develop branch of the working repository, and update the corresponding paths in config and XML files.

After using the builds command be sure to run composer update to sync your vendor folder with the latest target build. Then, check the Upgrading From a Previous Version and update project files if necessary.

Next Minor Version

If you want to use the next minor version branch, after using the builds command edit composer.json manually.

If you try the 4.6 branch, change the version to 4.6.x-dev:

"require": {
    "php": "^8.1",
    "codeigniter4/codeigniter4": "4.6.x-dev"
},

And run composer update to sync your vendor folder with the latest target build. Then, check the Upgrading Guide (user_guide_src/source/installation/upgrade_{version}.rst) and update project files if necessary.

Revert to Stable Release

To revert the changes run:

php builds release

Adding CodeIgniter4 to an Existing Project 

The same CodeIgniter 4 framework repository described in “Manual Installation” can also be added to an existing project using Composer.

Installation 

Develop your app inside the app folder, and the public folder will be your document root.

In your project root:

composer require codeigniter4/framework

Important

When you deploy to your production server, don’t forget to run the following command:

composer install --no-dev

The above command will remove the Composer packages only for development that are not needed in the production environment. This will greatly reduce the vendor folder size.

Setting Up 

Copy the app, public, tests and writable folders from vendor/codeigniter4/framework to your project root

Copy the env, phpunit.xml.dist and spark files, from vendor/codeigniter4/framework to your project root

You will have to adjust the $systemDirectory property in app/Config/Paths.php to refer to the vendor one, e.g., __DIR__ . '/../../vendor/codeigniter4/framework/system'.

Initial Configuration 

A few initial configurations are required. See Initial Configuration for the details.

Upgrading 

Whenever there is a new release, then from the command line in your project root:

composer update

Read the upgrade instructions and change log, and check Breaking Changes and Enhancements.

Upgrading to a Specified Version

For example, you may want to upgrade from v4.4.7 to v4.4.8 after v4.5.0 has been released.

In that case, open composer.json in your project root folder, and specify the framework version:

"require": {
    ...
    "codeigniter4/framework": "4.4.8"
},

Then, run the composer update command.

Pros 

Relatively simple installation; easy to update.

Cons 

You still need to check for file changes in the project space (root, app, public, writable) after updating.

Note

There are some third-party CodeIgniter modules available to assist with merging changes to the project space: Explore on Packagist.

Structure 

Folders in your project after set up:

app, public, tests, writable
vendor/codeigniter4/framework/system

Translations Installation 

If you want to take advantage of the system message translations, they can be added to your project in a similar fashion.

From the command line inside your project root:

composer require codeigniter4/translations

These will be updated along with the framework whenever you do a composer update.