Module: Formtastic::Helpers::InputHelper

Included in:
Defined in:


#input is used to render all content (labels, form widgets, error messages, hints, etc) for a single form input (or field), usually representing a single method or attribute on the form's object or model.

The content is wrapped in an <li> tag, so it's usually called inside an inputs block (which renders an <ol> inside a <fieldset>), which should be inside a semantic_form_for block:

<%= semantic_form_for @post do |f| %>
  <%= f.inputs do %>
    <%= f.input :title %>
    <%= f.input :body %>
  <% end %>
<% end %>

The HTML output will be something like:

<form class="formtastic" method="post" action="...">
      <li class="string required" id="post_title_input">
      <li class="text required" id="post_body_input">

Constant Summary

Instance Method Summary collapse

Instance Method Details

#input(method, options = {}) ⇒ Object


document the "guessing" of input style


Can we deprecate & kill :label, :hint & :prompt? All strings could be shifted to i18n!


Many many more examples. Some of the detail probably needs to be pushed out to the relevant methods too.


More i18n examples.

Returns a chunk of HTML markup for a given method on the form object, wrapped in an <li> wrapper tag with appropriate class and id attribute hooks for CSS and JS. In many cases, the contents of the wrapper will be as simple as a <label> and an <input>:

<%= f.input :title, :as => :string, :required => true %>

<li class="string required" id="post_title_input">
  <label for="post_title">Title<abbr title="Required">*</abbr></label>
  <input type="text" name="post[title]" value="" id="post_title" required="required">

In other cases (like a series of checkboxes for a has_many relationship), the wrapper may include more complex markup, like a nested <fieldset> with a <legend> and an <ol> of checkbox/label pairs for each choice:

<%= f.input :categories, :as => :check_boxes, :collection => %>

<li class="check_boxes" id="post_categories_input">
        <label><input type="checkbox" name="post[categories][1]" value="1"> Ruby</label>
        <label><input type="checkbox" name="post[categories][2]" value="2"> Rails</label>
        <label><input type="checkbox" name="post[categories][2]" value="2"> Awesome</label>

Sensible defaults for all options are guessed by looking at the method name, database column information, association information, validation information, etc. For example, a :string database column will map to a :string input, but if the method name contains 'email', will map to an :email input instead. belongs_to associations will have a :select input, etc.

Formtastic supports many different styles of inputs, and you can/should override the default with the :as option. Internally, the symbol is used to map to a protected method responsible for the details. For example, :as => :string will map to string_input, defined in a module of the same name. Detailed documentation for each input style and it's supported options is available on the *_input method in each module (links provided below).

Available input styles:

Calling :as => :string (for example) will call #to_html on a new instance of Formtastic::Inputs::StringInput. Before this, Formtastic will try to instantiate a top-level namespace StringInput, meaning you can subclass and modify Formtastic::Inputs::StringInput in app/inputs/. This also means you can create your own new input types in app/inputs/.


Accept all default options

<%= f.input :title %>

Change the input type

<%= f.input :title, :as => :string %>

Changing the label with a String

<%= f.input :title, :label => "Post title" %>

Disabling the label with false, even if an i18n translation exists

<%= f.input :title, :label => false  %>

Changing the hint with a String

<%= f.input :title, :hint => "Every post needs a title!" %>

Disabling the hint with false, even if an i18n translation exists

<%= f.input :title, :hint => false  %>

Marking a field as required or not (even if validations do not enforce it)

<%= f.input :title, :required => true  %>
<%= f.input :title, :required => false  %>

Changing or adding to HTML attributes in the main <input> or <select> tag

<%= f.input :title, :input_html => { :onchange => "somethingAwesome();", :class => 'awesome' } %>

Changing or adding to HTML attributes in the wrapper <li> tag

<%= f.input :title, :wrapper_html => { :class => "important-input" } %>

Changing the association choices with :collection

<%= f.input :author,     :collection => %>
<%= f.input :categories, :collection => Category.where(...).order(...) %>
<%= f.input :status,     :collection => ["Draft", "Published"] %>
<%= f.input :status,     :collection => [:draft, :published] %>
<%= f.input :status,     :collection => {"Draft" => 0, "Published" => 1} %>
<%= f.input :status,     :collection =>"Draft" => 0, "Published" => 1) %>
<%= f.input :status,     :collection => [["Draft", 0], ["Published", 1]] %>
<%= f.input :status,     :collection => grouped_options_for_select(...) %>
<%= f.input :status,     :collection => options_for_select(...) %>

Specifying if a :select should allow multiple selections:

<%= f.input :cateogies, :as => :select, :multiple => true %>
<%= f.input :cateogies, :as => :select, :multiple => false %>

Specifying if a :select should have a 'blank' first option to prompt selection:

<%= f.input :author, :as => :select, :include_blank => true %>
<%= f.input :author, :as => :select, :include_blank => false %>

Specifying the text for a :select input's 'blank' first option to prompt selection:

<%= f.input :author, :as => :select, :prompt => "Select an Author" %>

Modifying an input to suit your needs in app/inputs:

class StringInput < Formtastic::Inputs::StringInput
  def to_html
    puts "this is my custom version of StringInput"

Creating your own input to suit your needs in app/inputs:

class DatePickerInput
  include Formtastic::Inputs::Base
  def to_html
    # ...

Providing HTML5 placeholder text through i18n:

       email: ""
       first_name: "Joe"
       last_name: "Smith"


  • method (Symbol)

    The database column or method name on the form object that this input represents

  • options (Hash) (defaults to: {})

    a customizable set of options

Options Hash (options):

  • :as (Symbol)

    Override the style of input should be rendered

  • :label (String, Symbol, false)

    Override the label text

  • :hint (String, Symbol, false)

    Override hint text

  • :required (Boolean)

    Override to mark the input as required (or not) — adds a required/optional class to the wrapper, and a HTML5 required attribute to the <input>

  • :input_html (Hash)

    Override or add to the HTML attributes to be passed down to the <input> tag

  • :wrapper_html (Hash)

    Override or add to the HTML attributes to be passed down to the wrapping <li> tag

  • :collection (Array<ActiveModel, String, Symbol>, Hash{String => String, Boolean}, OrderedHash{String => String, Boolean})

    Override collection of objects in the association (:select, :radio & :check_boxes inputs only)

  • :multiple (Boolean)

    Specify if the :select input should allow multiple selections or not (defaults to belongs_to associations, and true for has_many and has_and_belongs_to_many associations)

  • :include_blank (Boolean)

    Specify if a :select input should include a blank option or not (defaults to include_blank_for_select_by_default configuration)

  • :prompt (String)

    Specify the text in the first ('blank') :select input <option> to prompt a user to make a selection (implicitly sets :include_blank to true)

See Also:

  • #namespaced_input_class

# File 'lib/formtastic/helpers/input_helper.rb', line 234

def input(method, options = {})
  method = method.to_sym
  options = options.dup # Allow options to be shared without being tainted by Formtastic
  options[:as] ||= default_input_type(method, options)

  klass = input_class(options[:as]), template, @object, @object_name, method, options).to_html