**Course Title:** Mastering Symfony: Building Enterprise-Level PHP Applications **Section Title:** Introduction to Symfony and Development Setup **Topic:** Setting up a Symfony development environment (Composer, Symfony CLI) In the previous topic, we provided an overview of the Symfony framework and its components. Now, we'll dive into setting up a Symfony development environment using Composer and Symfony CLI. This topic is crucial in laying the foundation for a successful project. ### What is Composer? Composer is a dependency manager for PHP. It allows you to declare the dependencies required for your project and manages them for you. With Composer, you can easily install, update, and manage dependencies in your project. [Composer Documentation](https://getcomposer.org/doc/). ### Installing Composer To install Composer, follow these steps: 1. Open a terminal and run the following command to download the Composer installer: ```bash curl -sS https://getcomposer.org/installer -o composer-setup.php ``` 2. Run the following command to verify the installer: ```bash HASH="67cea...46a4" # you can find the hash on the Composer download page php -r "if (hash_file('SHA384', 'composer-setup.php') === '$HASH') { echo 'Installer verified'; } else { echo 'Installer corrupt'; unlink('composer-setup.php'); } echo PHP_EOL;" ``` 3. Run the following command to install Composer: ```bash php composer-setup.php --install-dir=/usr/local/bin --filename=composer ``` or ```bash sudo mv composer-setup.php /usr/local/bin/composer ``` or ```bash php composer-setup.php ``` 4. Run the following command to verify Composer installation: ```bash composer ``` ### What is Symfony CLI? Symfony CLI is a command-line tool that provides a set of useful commands for Symfony developers. It allows you to create, manage, and test Symfony projects, among other things. [Symfony CLI Documentation](https://symfony.com/doc/current/setup.html#symfony-cli). ### Installing Symfony CLI To install Symfony CLI, follow these steps: 1. Open a terminal and run the following command to download the Symfony CLI installer: ```bash curl -sS https://clr.fyi | php ``` or ```bash curl -sS https://get.symfony.com/cli/installer -o symfony ``` or ```bash curl -sS https://get.symfony.com/cli/setup.exe -o symfony ``` 2. Run the following command to verify Symfony CLI installation: ```bash symfony ``` ### Creating a New Symfony Project Now that you have Composer and Symfony CLI installed, you can create a new Symfony project using the following command: ```bash composer create-project symfony/skeleton ``` or ```bash symfony new my_project_name ``` This will create a new Symfony project in a directory named `my_project_name`. ### Key Concepts * Composer is a dependency manager for PHP. * Symfony CLI is a command-line tool for Symfony developers. * Composer and Symfony CLI are essential tools for setting up a Symfony development environment. ### Practical Takeaways * Use Composer to manage dependencies in your project. * Use Symfony CLI to create, manage, and test Symfony projects. * Always verify the integrity of the Composer and Symfony CLI installers before installing. ### What's Next? In the next topic, we'll cover 'Introduction to Symfony's directory structure and MVC architecture.' This will give you a deeper understanding of how Symfony projects are organized and how the Model-View-Controller (MVC) pattern is implemented in Symfony. Do you have any questions or need help with setting up your Symfony development environment? Leave a comment below.