General information about views in Ruby on Rails 

Views are the part of a web application that is responsible for how information is displayed to users on a page. It defines how the data will look and how it will be structured. In Ruby on Rails, views are created using templates that help design the page.  

The purpose of the article 

The purpose of this article is to explain and demonstrate key concepts related to views in Ruby on Rails . We'll look at how to create views, how they interact with other components of a web application, and how they help developers create stylish and intuitive web pages. For better understanding, we'll also provide code examples and illustrations to show how it all works in practice. So, let's move on and learn more about how Ruby on Rails helps us manage views, create structured pages, and give them a user-friendly look. 

Visualization of information: Views in Ruby on Rails 

The basic concept of views

The main purpose of views in Ruby on Rails is to separate the logic of the application and the appearance of the pages. Views are responsible for how data is interpreted and displayed on a web page. They take the form of HTML templates in which you can embed dynamic data. It helps to create very dynamic and interactive pages. 

The role of Slim and other patterns in Ruby on Rails 

Ruby on Rails supports several different templating languages, and one popular one is Slim . Slim is a minimalist template language that allows you to write HTML code more compactly and clearly. It is ideal for working with views in Rails , as it allows you to quickly create structured and understandable templates. 

In addition to Slim , Ruby on Rails supports other patterns such as ERB (Embedded Ruby), Haml , and many others. Choosing a template is a matter of the developer's taste, and everyone can choose the one they like best and suit their needs. I personally use Slim on my projects.

Directory structure and view files 

In Rails , the view directory structure is pretty standard. It is usually located in the folder. Each controller has its own folder with a name that corresponds to the name of the controller. For example, if you have a controller named ArticlesController , then the corresponding views are stored in the folder app/views/articles.

Each view folder can have different templates for different controller actions. For example, for the show action , the template will have the name show.html.slim . For index action - index.html.slim and so on. This framework helps Rails automatically determine which view to use for each controller action. 

This way, you can create structured and organized views for your Ruby on Rails application . In the following parts of the article, we will take a closer look at how to create these views and how they interact with other components of the application. 

Using render and render partial methods 

Ruby on Rails uses the render and render partial methods to display information on a page . 

The render method is used to display the entire view . It tells Rails which view to use for a particular controller action. For example, you have a show action in the Articles controller , and you want to display information about a specific article. For this you use: 

def show
  @article = Article.find(params[:id])
  render :show
end

The render method tells Rails to use a view show.html.slim to render the page. 

render partial , on the other hand, is used to display a portion of a view that can be embedded in other pages. For example, if you have a block with a list of articles and you want to display it on several different pages, then you use render partial : 

# Displays the list of articles on the 'index' page 
def  index
   @articles  = Article . all
 end

# app/views/articles/index.html.slim
h1 Articles
= render partial: 'article', collection: @articles

# app/views/articles/_article.html.slim
.article
  h2 = article.title
  p = article.content

In this example, the render partial uses a template for each article in the @articles collection, inserting them into the page _article.html.slim. 

Passing variables and data to the view 

To pass variables and data to a view in Ruby on Rails , you can use controller instance variables. For example, in the show controller action we discussed earlier, we pass the @article variable to the view: 

def show
  @article = Article.find(params[:id])
  render :show
end

 In the view , you can access this variable: show.html.slim 

h1 =  @article . title 
p =  @article . content

This allows you to display information from the database on the page.