Form Helpers | Rails Views | Rubyonrails Tutorial

Introduction

Form helpers in Rails simplify the process of creating forms and managing form data. They provide a convenient way to generate form elements and handle form submissions, ensuring your forms are secure and easy to use. This guide will cover the basics of using form helpers in Rails views.

Key Points:

Form helpers generate form elements and handle form submissions.
They ensure that forms are secure by including authenticity tokens.
This guide covers the most commonly used form helpers in Rails.

Using `form_with`

The form_with helper is the primary way to create forms in Rails. It automatically generates the appropriate form tag and includes an authenticity token for security. Here is a basic example:

<!-- app/views/articles/new.html.erb -->
<%= form_with model: @article do |form| %>
  <div>
    <%= form.label :title %>
    <%= form.text_field :title %>
  </div>
  <div>
    <%= form.label :body %>
    <%= form.text_area :body %>
  </div>
  <div>
    <%= form.submit 'Save' %>
  </div>
<% end %>

In this example, a form is created for the @article model with fields for the title and body, and a submit button.

Common Form Helpers

Rails provides several form helpers to generate different types of form elements. Here are some of the most commonly used form helpers:

text_field: Creates a text input field.
text_area: Creates a text area.
password_field: Creates a password input field.
hidden_field: Creates a hidden input field.
file_field: Creates a file input field.
check_box: Creates a checkbox.
radio_button: Creates a radio button.
select: Creates a dropdown select box.
date_select: Creates a date select dropdown.
submit: Creates a submit button.

Example Form with Common Helpers

Here is an example of a form using various form helpers:

<!-- app/views/users/new.html.erb -->
<%= form_with model: @user do |form| %>
  <div>
    <%= form.label :username %>
    <%= form.text_field :username %>
  </div>
  <div>
    <%= form.label :email %>
    <%= form.text_field :email %>
  </div>
  <div>
    <%= form.label :password %>
    <%= form.password_field :password %>
  </div>
  <div>
    <%= form.label :gender %>
    <%= form.radio_button :gender, 'male' %> Male
    <%= form.radio_button :gender, 'female' %> Female
  </div>
  <div>
    <%= form.label :terms_of_service %>
    <%= form.check_box :terms_of_service %>
  </div>
  <div>
    <%= form.label :country %>
    <%= form.select :country, ['USA', 'Canada', 'UK'] %>
  </div>
  <div>
    <%= form.submit 'Sign Up' %>
  </div>
<% end %>

Handling File Uploads

To handle file uploads, use the file_field helper and ensure your form has the appropriate encoding type. Here is an example:

<!-- app/views/users/edit.html.erb -->
<%= form_with model: @user, local: true, html: { multipart: true } do |form| %>
  <div>
    <%= form.label :avatar %>
    <%= form.file_field :avatar %>
  </div>
  <div>
    <%= form.submit 'Update Profile' %>
  </div>
<% end %>

Using Form Builders

Form builders provide an easy way to generate forms for complex objects. Rails comes with the FormBuilder class that can be customized for specific needs. Here is an example of a custom form builder:

# app/helpers/custom_form_builder.rb
class CustomFormBuilder < ActionView::Helpers::FormBuilder
  def text_field(attribute, options = {})
    label(attribute) + super
  end
end

# app/views/articles/new.html.erb
<%= form_with model: @article, builder: CustomFormBuilder do |form| %>
  <%= form.text_field :title %>
  <%= form.text_area :body %>
  <%= form.submit 'Save' %>
<% end %>

Conclusion

Form helpers in Rails make it easy to create forms and handle form data securely and efficiently. By using the various form helpers provided by Rails, you can build complex forms quickly and ensure they are maintainable and secure.

Ruby on Rails - Form Helpers