**Course Title:** Ruby Programming: From Basics to Advanced Techniques **Section Title:** Advanced Rails: Routing and Views **Topic:** Creating and using views with ERB and HAML ### Overview of Views in Rails In Rails, a view is responsible for rendering the user interface of your application. It's the part of the MVC architecture that deals with displaying data to the end-user. Rails supports multiple templating engines for creating views, with ERb (Embedded RuBy) and HAML being two of the most popular ones. In this topic, we'll explore how to create and use views with ERb and HAML. ### ERb (Embedded RuBy) ERb is a templating engine that allows you to embed Ruby code into your HTML views. It's the default templating engine in Rails and is very flexible. **Syntax:** In ERb, you can use the following syntax to embed Ruby code: * `<% %>`, which executes the code but doesn't print the result * `<%= %>`, which executes the code and prints the result * `<%# %>`, which is used for comments **Example:** Let's create a simple view that displays the list of users: ```html <!-- users/index.html.erb --> <h1>Users</h1> <ul> <% @users.each do |user| %> <li><%= user.name %> (<%= user.email %>)</li> <% end %> </ul> ``` In this example, we're using the `<% %>``` and `<%= %>`` syntax to execute and print Ruby code. The `@users` variable is an instance variable that's available in the view. ### HAML HAML (HTML Abstraction Markup Language) is another popular templating engine for Rails. It's known for its simplicity and readability. **Syntax:** In HAML, you can use the following syntax to embed Ruby code: * `-` is used to execute Ruby code * `=` is used to print the result of Ruby code * `#` is used for comments **Example:** Let's create the same view using HAML: ```haml <!-- users/index.html.haml --> %h1 Users %ul - @users.each do |user| %li = user.name (#{user.email}) ``` In this example, we're using the `-` syntax to execute Ruby code and the `=` syntax to print the result. ### Using Helpers Rails provides a number of helpers that can be used in views to perform common tasks. For example, you can use the `link_to` helper to create links, or the `image_tag` helper to display images. **Example:** ```html <!-- users/index.html.erb --> <h1>Users</h1> <ul> <% @users.each do |user| %> <li> <%= link_to user.name, user_path(user) %> (<%= image_tag(user.avatar_url) %>) </li> <% end %> </ul> ``` In this example, we're using the `link_to` and `image_tag` helpers to create links and display images. ### Best Practices Here are some best practices to keep in mind when creating views in Rails: * Use partials to break up large views into smaller, reusable pieces * Use helpers to perform common tasks * Avoid using instance variables in views; instead, pass data from the controller * Use ERb or HAML consistently throughout your application ### Conclusion In this topic, we've covered how to create and use views with ERb and HAML in Rails. We've also discussed how to use helpers and best practices for creating views. For more information, refer to the [Rails documentation on views](https://guides.rubyonrails.org/layouts_and_rendering.html). **Practical Exercise:** Create a new Rails application and create a view that displays a list of users using ERb or HAML. Use helpers to create links and display images. **Leave a comment or ask for help:** Have you completed the practical exercise? Do you have any questions or need help with creating views in Rails? Leave a comment below and we'll be happy to help. **Next Topic:** In the next topic, we'll cover layouts and partials for better code organization.