Why views present data in Ruby on Rails - Challenge Your Understanding

Challenge - 5 Problems

🧠 Conceptual

intermediate

Why do views in Rails present data?

In a Rails application, what is the main reason views are responsible for presenting data?

A To separate the user interface from the business logic, making the app easier to maintain.

B To handle database queries and data storage directly.

C To process user input and perform calculations.

D To manage server configuration and routing.

💡 Hint

Think about the role of views in showing information to users.

Views in Rails are designed to display data to users. They keep the user interface separate from the logic and data handling, which happens in controllers and models.

❓ component_behavior

intermediate

What does a Rails view render?

Given a Rails controller passes @user = User.find(1) to the view, what will the view typically render?

Ruby on Rails

<%= @user.name %>

A Nothing, because views cannot access instance variables.

B The name attribute of the user with ID 1.

C An error because @user is not defined in the view.

D The entire user object as a string.

💡 Hint

Instance variables set in controllers are accessible in views.

The controller sets @user, which the view can use to show the user's name. This is how data is passed to views for display.

❓ state_output

advanced

Output of a view rendering a collection

What will this Rails view code output if @products = [Product.new(name: 'Pen'), Product.new(name: 'Book')]?

Ruby on Rails

<ul>
  <% @products.each do |product| %>
    <li><%= product.name %></li>
  <% end %>
</ul>

A <ul></ul>

B <ul><li>@products</li></ul>

C An error because product.name is undefined.

D <ul><li>Pen</li><li>Book</li></ul>

💡 Hint

Each product's name is shown inside list items.

The view loops over each product and displays its name inside <li> tags, resulting in a list of product names.

📝 Syntax

advanced

Identify the correct ERB syntax for outputting data

Which option correctly outputs the variable @message in a Rails view using ERB?

A <%== @message %>

B <% @message %>

C <%= @message %>

D <%: @message %>

💡 Hint

ERB tags with '=' output content to the view.

The <%= %> tag outputs the value of @message. The others either do not output or are invalid syntax.

🔧 Debug

expert

Why does this view raise an error?

Given the controller sets @user = User.find(params[:id]), why does this view code raise an error?

<%= @user.email_address %>

A The User model does not have an attribute named email_address.

B Instance variables are not accessible in views.

C The controller did not pass @user to the view.

D The syntax <code><%= %></code> is incorrect for outputting variables.

💡 Hint

Check the attribute names defined in the User model.

If the User model uses email instead of email_address, accessing @user.email_address causes a NoMethodError.