The document discusses various Rails form helpers and gems including form_for, simple_form, nested_form, and building custom form builders. Simple_form adds clean and semantic forms while nested_form handles forms for nested attributes. A custom form builder can be created by inheriting from ActionView::FormBuilder to add custom methods like field_item.

1. Rails View – Chapter 5: Form
• Form Helper
• Simple Form (gem)
• Nested Form (gem)
• Custom Form

2. Form Helper
form_for:
we use it for smart model object.
form_tag:
we use it for non-smart model object. (search
form…)

3. Form Helper
= form_for @creation, html: {multipart: true} do |f|
= f.label :name
= f.text_field :name
= f.label :description
= f.text_area :description, cols: 40, rows: 4
= f.file_field :file
= f.label :file
= f.submit

4. Simple Form
Add it to your Gemfile:
gem 'simple_form'
Run the following command to install it:
bundle install
Run the generator:
rails generate simple_form:install
Run the generator with bootstrap:
rails generate simple_form:install --bootstrap

5. Simple Form
= simple_form_for @user do |f|
= f.input :username
= f.input :password
= f.button :submit

6. Simple Form
simple_form_for @user do |f|
= f.input :username, label: “Your username please”
= f.input :password, hint: “No special characters.”
= f.input :email, placeholder: “user@domain.com”
= f.input :remember_me, inline_label: “Yes,
remember me”
= f.button :submit

7. Simple Form
input_html:
pass any html attribute straight to the input.
label_html:
pass any html attribute straight to the label.
wrapper_html:
pass any html attribute straight to the div wrapper.

8. Simple Form
= simple_form_for @user do |f|
= f.input :username, label_html: { class: “special” }
= f.input :password, input_html: { maxlength: 20 }
= f.input :remember_me, wrapper_html: { id:
“wrapper” }
= f.button :submit

9. Simple Form
= simple_form_for @user, defaults: { input_html:
{ class: 'default_class' } } do |f|
= f.input :name, required: false
= f.input :description, as: :text
= f.input :accepts, as: :radio_buttons

10. Simple Form
= f.input :price, wrapper: :prepend do
= content_tag :span, “USD”, class: “add-on”
= f.input_field :price
## Output
<div class=“input-prepend”>
<span class=“add-on”>USD</span>
<input class=“numeric decimal required” id=“food_price”
name=“food[price]” type=“text”>

11. Simple Form
user belongs_to company, company has_many users
user has_many roles, role belongs_to user
= simple_form_for @user do |f|
= f.input :name
= f.association :company
= f.association :roles
= f.button :submit

12. Simple Form
as: :radio_buttons
as: :check_boxes
collection: Company.active.all
prompt: "Choose a Company“
include_blank: false
label_method: :name
value_method: :uuid

13. Simple Form
= simple_form_for @user do |f|
= f.input :name
= f.simple_field_for :image do |img|
= img.input :photo, as: :file

14. Nested Form
This gem is applied to nested form.
• form_for => nested_form_for
• simple_form_for => simple_nested_form_for

15. Nested Form
= simple_form_for @user do |f|
= f.input :name
= f.simple_field_for :images do |img|
= img.input :photo, as: :file
= img.link_to_remove “remove this image”
%p
f.link_to_add “add image”, :images

16. Custom Form
## artflow/forms/lib/application_form_builder.rb
class ApplicationFormBuilder <
ActionView::Helpers::FormBuilder
End
## artflow/forms/config/application.rb
config.autoload_paths += %W(#{config.root}/lib)

17. Custom Form
= f.field_item :name do
= f.text_field :name
## artflow/forms/lib/application_form_builder.rb
def field_item(attribute, text = nil, &block)
@template.content_tag :li do
@template.concat @template.label(attribute, text)
yield
end
end

18. Custom Form
Hook It Up
= form_for @creation, builder: ApplicationFormBuilder,
html: {multipart: true} do |f|
## artflow/forms/config/initializers/form_builder_initializer.rb
ActionView::Base.default_form_builder = ApplicationFormBuilder

19. Reference
- simple_form: (https://github.com/plataformatec/simple_form)
- nested_form: (https://github.com/ryanb/nested_form)

20. The End