**Course Title:** Mastering Ruby on Rails: Building Scalable Web Applications **Section Title:** Introduction to Ruby on Rails and Development Environment **Topic:** Setting up the Rails development environment (Ruby, Bundler, Rails gem) **Setting Up the Rails Development Environment** Welcome to this topic on setting up the Rails development environment. In the previous topic, we covered an overview of Ruby and Rails, including their history and current trends. In this topic, we will delve into the specifics of setting up the Rails development environment, which includes Ruby, Bundler, and the Rails gem. **Prerequisites** Before proceeding, ensure you have: 1. A computer with a compatible operating system (Windows, macOS, or Linux) 2. A code editor or IDE (Integrated Development Environment) of your choice (e.g., Visual Studio Code, Atom, Sublime Text) 3. Internet access for downloading and installing the required tools **Setting Up Ruby** Ruby is the programming language used for building Rails applications. To set up Ruby on your system, follow these steps: 1. **Check if Ruby is already installed**: Open your terminal or command prompt and type `ruby -v`. If you see a Ruby version number, then Ruby is already installed on your system. 2. **Install Ruby using a package manager or installer**: * **On Windows**: Install Ruby using the RubyInstaller available at [https://rubyinstaller.org/](https://rubyinstaller.org/). * **On macOS** (using Homebrew): Run `brew install ruby` in your terminal. * **On Linux** (using apt-get): Run `sudo apt-get install ruby` in your terminal. **Setting Up Bundler** Bundler is a gem manager for Ruby that helps manage your gem dependencies. To set up Bundler, follow these steps: 1. **Install Bundler**: Run `gem install bundler` in your terminal. 2. **Verify Bundler installation**: Run `bundle -v` to verify that Bundler is correctly installed. **Setting Up Rails** To set up Rails, follow these steps: 1. **Install the Rails gem**: Run `gem install rails` in your terminal. 2. **Verify Rails installation**: Run `rails -v` to verify that Rails is correctly installed. **Creating a New Rails Application** Now that you have Ruby, Bundler, and Rails set up on your system, you can create a new Rails application using the following command: ```bash rails new my_app_name ``` This will create a new Rails application in a directory called `my_app_name`. **Understanding the Rails Project Directory Structure** After creating a new Rails application, navigate to the project directory and explore the directory structure: ```bash cd my_app_name ls -l ``` The Rails project directory structure includes the following directories: * `app/`: This is where you'll write your application code. * `config/`: This is where you'll store your application's configuration files. * `db/`: This is where you'll store your database schema and migrations. * `lib/`: This is where you'll store library code that can be used across your application. * `log/`: This is where you'll store log files for your application. * `public/`: This is where you'll store static assets for your application. * `test/`: This is where you'll write unit tests and integration tests for your application. **Conclusion** In this topic, we covered setting up the Rails development environment, including Ruby, Bundler, and the Rails gem. We also created a new Rails application and explored the project directory structure. **Practical Takeaways** * Set up Ruby on your system using a package manager or installer. * Install Bundler and verify its installation. * Install the Rails gem and verify its installation. * Create a new Rails application using the `rails new` command. * Explore the Rails project directory structure. **What's Next?** In the next topic, we'll cover **Understanding MVC (Model-View-Controller) architecture**. **Do you have any questions or need help with this topic? Feel free to ask in the comments below.**