J4.x:Setting Up Your Local Environment

From Joomla! Documentation

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How to Setup a Local Environment for Joomla 4

With Joomla 4 we have changed the development process. It is no longer possible to clone the repository and have a usable Joomla installation. We follow best practices and implement a build process for the CMS.

Quick Start Guide

The steps to setup your development environment depend on your operating system. We can not write documentation for any OS so you should use your favorite search engine to find a HowTo.

Tools You Need

  1. PHP - basically the same as you need for running a Joomla site, but you need the PHP CLI (command line interface) version. (See the Configuring a LAMPP server for PHP development page.)
  2. Composer - for managing Joomla's PHP dependencies. For help installing Composer, read the documentation at https://getcomposer.org/doc/00-intro.md.
  3. Node.js - for compiling Joomla's JavaScript and SASS files. For help installing Node.js, please follow the instructions available on https://nodejs.org/en/.
  4. Git - for version management.

Steps to Setup the Local Environment

  1. Clone the repository.
  2. Run composer install from the root of the git repo. (You can add --ignore-platform-reqs if you don't have the PHP-LDAP locally installed and you don't need it.)
  3. Run npm ci from the root of the git repo. (Note you need npm 5.7 or higher for this. Run npm install -g npm@lts to upgrade your version of npm to the lts version.)

Linux and OSX users can set up the following bash alias by placing the following inside the ~/.bashrc file:

alias jinstall="rm -rf administrator/templates/atum/css; rm -rf templates/cassiopeia/css; rm -rf media/; rm -rf node_modules/; rm -rf libraries/vendor/; composer install; npm ci; git checkout -- libraries/vendor/.htaccess"

This will delete all the compiled files in your system and run a fresh install as one command by calling jinstall inside your Joomla install.

A Bit Longer Start Guide

Joomla is similar to many other web tools these days. It has a large PHP part and it has more and more JavaScript code. While PHP coding doesn't need so much preparation, JavaScript needs a lot tooling around. The main reason is that nobody writes code in a way that every browser understands, so the code needs transpiling from e.g. ES6 to a compatible version of JavaScript. The same is true for CSS. For Joomla we are using SASS and this will be converted to native CSS so that any browser understands it. On the downside, setting up a development environment is a bit more complicated but the tooling makes coding more convenient. Thanks to watchers and browser auto reload, you can see your changes in real time.


It should be enough to run composer install as this will install PHP dependencies saved in the composer.lock file. You can do this as many times as you like. It will only install new packages when the composer.lock file is changed. Don't run composer update as this will update all packages to newer versions and update the composer.lock file.

Note: You may need to run composer install with the --ignore-platform-reqs option to ignore platform requirements specified in Composer. That is, if you do not have PHP's LDAP extension installed.

Node/npm Scripts

Node.js comes with a package manager called NPM (in some ways the same as Composer). NPM has a run command and we have prepared some scripts to make your life easier. You have to run the commands for the root of the repository

npm run build:css

It will compile SASS files to CSS and also create the minified files.

npm run build:js

It will compile and transpile the JavaScript files to the correct format and create minified files.

npm run watch:css

This is the same as the build:css command but will watch for changes and automatically build updated files.

npm run watch:js

This is the same as the build:js command but will watch for changes and automatically build updated files.

npm run lint:js

This will perform a syntax check on JavaScript files.

npm run test

This will run a JavaScript testing suite.

Possible Issues

If you receive a login error such as shown below, delete the \library\autoload_psr4.php file as shown in the second image. Login After Install Error autoload_psr4.php