# module ActionView::Helpers::FormHelper

Form helpers are designed to make working with resources much easier compared to using vanilla HTML.

Forms for models are created with `form_for`. That method yields a form builder that knows the model the form is about. The form builder is thus able to generate default values for input fields that correspond to model attributes, and also convenient names, IDs, endpoints, etc.

Conventions in the generated field names allow controllers to receive form data nicely structured in `params` with no effort on your side.

For example, to create a new person you typically set up a new instance of `Person` in the `PeopleController#new` action, `@person`, and pass it to `form_for`:

    <%= form_for @person do |f| %>
      <%= f.label :first_name %>:
      <%= f.text_field :first_name %><br />

      <%= f.label :last_name %>:
      <%= f.text_field :last_name %><br />

      <%= f.submit %>
    <% end %>

The HTML generated for this would be (modulus formatting):

    <form action="/people" class="new_person" id="new_person" method="post">
      <div style="margin:0;padding:0;display:inline">
        <input name="authenticity_token" type="hidden" value="NrOp5bsjoLRuK8IW5+dQEYjKGUJDe7TQoZVvq95Wteg=" />
      </div>
      <label for="person_first_name">First name</label>:
      <input id="person_first_name" name="person[first_name]" size="30" type="text" /><br />

      <label for="person_last_name">Last name</label>:
      <input id="person_last_name" name="person[last_name]" size="30" type="text" /><br />

      <input name="commit" type="submit" value="Create Person" />
    </form>

As you see, the HTML reflects knowledge about the resource in several spots, like the path the form should be submitted to, or the names of the input fields.

In particular, thanks to the conventions followed in the generated field names, the controller gets a nested hash `params[:person]` with the person attributes set in the form. That hash is ready to be passed to `Person.create`:

    if @person = Person.create(params[:person])
      # success
    else
      # error handling
    end

Interestingly, the exact same view code in the previous example can be used to edit a person. If `@person` is an existing record with name “John Smith” and ID 256, the code above as is would yield instead:

    <form action="/people/256" class="edit_person" id="edit_person_256" method="post">
      <div style="margin:0;padding:0;display:inline">
        <input name="_method" type="hidden" value="put" />
        <input name="authenticity_token" type="hidden" value="NrOp5bsjoLRuK8IW5+dQEYjKGUJDe7TQoZVvq95Wteg=" />
      </div>
      <label for="person_first_name">First name</label>:
      <input id="person_first_name" name="person[first_name]" size="30" type="text" value="John" /><br />

      <label for="person_last_name">Last name</label>:
      <input id="person_last_name" name="person[last_name]" size="30" type="text" value="Smith" /><br />

      <input name="commit" type="submit" value="Update Person" />
    </form>

Note that the endpoint, default values, and submit button label are tailored for `@person`. That works that way because the involved helpers know whether the resource is a new record or not, and generate HTML accordingly.

The controller would receive the form data again in `params[:person]`, ready to be passed to `Person#update_attributes`:

    if @person.update_attributes(params[:person])
      # success
    else
      # error handling
    end

That’s how you typically work with resources.

### Public Instance Methods

check_box(object_name, method, options = {}, checked_value = "1", unchecked_value = "0") click to toggle source

Returns a checkbox tag tailored for accessing a specified attribute (identified by `method`) on an object assigned to the template (identified by `object`). This object must be an instance object (@object) and not a local object. It’s intended that `method` returns an integer and if that integer is above zero, then the checkbox is checked. Additional options on the input tag can be passed as a hash with `options`. The `checked_value` defaults to 1 while the default `unchecked_value` is set to 0 which is convenient for boolean values.

#### Gotcha¶ ↑

The HTML specification says unchecked check boxes are not successful, and thus web browsers do not send them. Unfortunately this introduces a gotcha: if an `Invoice` model has a `paid` flag, and in the form that edits a paid invoice the user unchecks its check box, no `paid` parameter is sent. So, any mass-assignment idiom like

    @invoice.update_attributes(params[:invoice])

wouldn’t update the flag.

To prevent this the helper generates an auxiliary hidden field before the very check box. The hidden field has the same name and its attributes mimic an unchecked check box.

This way, the client either sends only the hidden field (representing the check box is unchecked), or both fields. Since the HTML specification says key/value pairs have to be sent in the same order they appear in the form, and parameters extraction gets the last occurrence of any repeated key in the query string, that works for ordinary forms.

Unfortunately that workaround does not work when the check box goes within an array-like parameter, as in

    <%= fields_for "project[invoice_attributes][]", invoice, :index => nil do |form| %>
      <%= form.check_box :paid %>
      ...
    <% end %>

because parameter name repetition is precisely what Rails seeks to distinguish the elements of the array. For each item with a checked check box you get an extra ghost item with only that attribute, assigned to “0”.

In that case it is preferable to either use `check_box_tag` or to use hashes instead of arrays.

#### Examples¶ ↑

    # Let's say that @post.validated? is 1:
    check_box("post", "validated")
    # => <input name="post[validated]" type="hidden" value="0" />
    #    <input type="checkbox" id="post_validated" name="post[validated]" value="1" />

    # Let's say that @puppy.gooddog is "no":
    check_box("puppy", "gooddog", {}, "yes", "no")
    # => <input name="puppy[gooddog]" type="hidden" value="no" />
    #    <input type="checkbox" id="puppy_gooddog" name="puppy[gooddog]" value="yes" />

    check_box("eula", "accepted", { :class => 'eula_check' }, "yes", "no")
    # => <input name="eula[accepted]" type="hidden" value="no" />
    #    <input type="checkbox" class="eula_check" id="eula_accepted" name="eula[accepted]" value="yes" />

    # File lib/action_view/helpers/form_helper.rb, line 840
    def check_box(object_name, method, options = {}, checked_value = "1", unchecked_value = "0")
      InstanceTag.new(object_name, method, self, options.delete(:object)).to_check_box_tag(options, checked_value, unchecked_value)
    end

convert_to_model(object) click to toggle source

Converts the given object to an ActiveModel compliant one.

    # File lib/action_view/helpers/form_helper.rb, line 109
    def convert_to_model(object)
      object.respond_to?(:to_model) ? object.to_model : object
    end

email_field(object_name, method, options = {}) click to toggle source

Returns a #text_field of type “email”.

    email_field("user", "address")
    # => <input id="user_address" size="30" name="user[address]" type="email" />

    # File lib/action_view/helpers/form_helper.rb, line 929
    def email_field(object_name, method, options = {})
      InstanceTag.new(object_name, method, self, options.delete(:object)).to_input_field_tag("email", options)
    end

fields_for(record_name, record_object = nil, options = {}, &block) click to toggle source

Creates a scope around a specific model object like #form_for, but doesn’t create the form tags themselves. This makes #fields_for suitable for specifying additional model objects in the same form.

### Generic Examples¶ ↑

    <%= form_for @person do |person_form| %>
      First name: <%= person_form.text_field :first_name %>
      Last name : <%= person_form.text_field :last_name %>

      <%= fields_for @person.permission do |permission_fields| %>
        Admin?  : <%= permission_fields.check_box :admin %>
      <% end %>

      <%= f.submit %>
    <% end %>

…or if you have an object that needs to be represented as a different parameter, like a Client that acts as a Person:

    <%= fields_for :person, @client do |permission_fields| %>
      Admin?: <%= permission_fields.check_box :admin %>
    <% end %>

…or if you don’t have an object, just a name of the parameter:

    <%= fields_for :person do |permission_fields| %>
      Admin?: <%= permission_fields.check_box :admin %>
    <% end %>

Note: This also works for the methods in FormOptionHelper and DateHelper that are designed to work with an object as base, like FormOptionHelper#collection_select and ActionView::Helpers::DateHelper#datetime_select.

### Nested Attributes Examples¶ ↑

When the object belonging to the current scope has a nested attribute writer for a certain attribute, #fields_for will yield a new scope for that attribute. This allows you to create forms that set or change the attributes of a parent object and its associations in one go.

Nested attribute writers are normal setter methods named after an association. The most common way of defining these writers is either with `accepts_nested_attributes_for` in a model definition or by defining a method with the proper name. For example: the attribute writer for the association `:address` is called `address_attributes=`.

Whether a one-to-one or one-to-many style form builder will be yielded depends on whether the normal reader method returns a single object or an array of objects.

#### One-to-one¶ ↑

Consider a Person class which returns a single Address from the `address` reader method and responds to the `address_attributes=` writer method:

    class Person
      def address
        @address
      end

      def address_attributes=(attributes)
        # Process the attributes hash
      end
    end

This model can now be used with a nested #fields_for, like so:

    <%= form_for @person do |person_form| %>
      ...
      <%= person_form.fields_for :address do |address_fields| %>
        Street  : <%= address_fields.text_field :street %>
        Zip code: <%= address_fields.text_field :zip_code %>
      <% end %>
      ...
    <% end %>

When address is already an association on a Person you can use `accepts_nested_attributes_for` to define the writer method for you:

    class Person < ActiveRecord::Base
      has_one :address
      accepts_nested_attributes_for :address
    end

If you want to destroy the associated model through the form, you have to enable it first using the `:allow_destroy` option for `accepts_nested_attributes_for`:

    class Person < ActiveRecord::Base
      has_one :address
      accepts_nested_attributes_for :address, :allow_destroy => true
    end

Now, when you use a form element with the `_destroy` parameter, with a value that evaluates to `true`, you will destroy the associated model (eg. 1, ‘1’, true, or ‘true’):

    <%= form_for @person do |person_form| %>
      ...
      <%= person_form.fields_for :address do |address_fields| %>
        ...
        Delete: <%= address_fields.check_box :_destroy %>
      <% end %>
      ...
    <% end %>

#### One-to-many¶ ↑

Consider a Person class which returns an array of Project instances from the `projects` reader method and responds to the `projects_attributes=` writer method:

    class Person
      def projects
        [@project1, @project2]
      end

      def projects_attributes=(attributes)
        # Process the attributes hash
      end
    end

Note that the `projects_attributes=` writer method is in fact required for #fields_for to correctly identify `:projects` as a collection, and the correct indices to be set in the form markup.

When projects is already an association on Person you can use `accepts_nested_attributes_for` to define the writer method for you:

    class Person < ActiveRecord::Base
      has_many :projects
      accepts_nested_attributes_for :projects
    end

This model can now be used with a nested fields_for. The block given to the nested #fields_for call will be repeated for each instance in the collection:

    <%= form_for @person do |person_form| %>
      ...
      <%= person_form.fields_for :projects do |project_fields| %>
        <% if project_fields.object.active? %>
          Name: <%= project_fields.text_field :name %>
        <% end %>
      <% end %>
      ...
    <% end %>

It’s also possible to specify the instance to be used:

    <%= form_for @person do |person_form| %>
      ...
      <% @person.projects.each do |project| %>
        <% if project.active? %>
          <%= person_form.fields_for :projects, project do |project_fields| %>
            Name: <%= project_fields.text_field :name %>
          <% end %>
        <% end %>
      <% end %>
      ...
    <% end %>

Or a collection to be used:

    <%= form_for @person do |person_form| %>
      ...
      <%= person_form.fields_for :projects, @active_projects do |project_fields| %>
        Name: <%= project_fields.text_field :name %>
      <% end %>
      ...
    <% end %>

When projects is already an association on Person you can use `accepts_nested_attributes_for` to define the writer method for you:

    class Person < ActiveRecord::Base
      has_many :projects
      accepts_nested_attributes_for :projects
    end

If you want to destroy any of the associated models through the form, you have to enable it first using the `:allow_destroy` option for `accepts_nested_attributes_for`:

    class Person < ActiveRecord::Base
      has_many :projects
      accepts_nested_attributes_for :projects, :allow_destroy => true
    end

This will allow you to specify which models to destroy in the attributes hash by adding a form element for the `_destroy` parameter with a value that evaluates to `true` (eg. 1, ‘1’, true, or ‘true’):

    <%= form_for @person do |person_form| %>
      ...
      <%= person_form.fields_for :projects do |project_fields| %>
        Delete: <%= project_fields.check_box :_destroy %>
      <% end %>
      ...
    <% end %>

    # File lib/action_view/helpers/form_helper.rb, line 603
    def fields_for(record_name, record_object = nil, options = {}, &block)
      builder = instantiate_builder(record_name, record_object, options, &block)
      output = capture(builder, &block)
      output.concat builder.hidden_field(:id) if output && options[:hidden_field_id] && !builder.emitted_hidden_id?
      output
    end

file_field(object_name, method, options = {}) click to toggle source

Returns a file upload input tag tailored for accessing a specified attribute (identified by `method`) on an object assigned to the template (identified by `object`). Additional options on the input tag can be passed as a hash with `options`. These options will be tagged onto the HTML as an HTML element attribute as in the example shown.

Using this method inside a `form_for` block will set the enclosing form’s encoding to `multipart/form-data`.

#### Examples¶ ↑

    file_field(:user, :avatar)
    # => <input type="file" id="user_avatar" name="user[avatar]" />

    file_field(:post, :attached, :accept => 'text/html')
    # => <input accept="text/html" type="file" id="post_attached" name="post[attached]" />

    file_field(:attachment, :file, :class => 'file_input')
    # => <input type="file" id="attachment_file" name="attachment[file]" class="file_input" />

    # File lib/action_view/helpers/form_helper.rb, line 750
    def file_field(object_name, method, options = {})
      InstanceTag.new(object_name, method, self, options.delete(:object)).to_input_field_tag("file", options.update({:size => nil}))
    end

form_for(record, options = {}, &block) click to toggle source

Creates a form and a scope around a specific model object that is used as a base for questioning about values for the fields.

Rails provides succinct resource-oriented form generation with `form_for` like this:

    <%= form_for @offer do |f| %>
      <%= f.label :version, 'Version' %>:
      <%= f.text_field :version %><br />
      <%= f.label :author, 'Author' %>:
      <%= f.text_field :author %><br />
      <%= f.submit %>
    <% end %>

There, `form_for` is able to generate the rest of RESTful form parameters based on introspection on the record, but to understand what it does we need to dig first into the alternative generic usage it is based upon.

### Generic #form_for¶ ↑

The generic way to call `form_for` yields a form builder around a model:

    <%= form_for :person do |f| %>
      First name: <%= f.text_field :first_name %><br />
      Last name : <%= f.text_field :last_name %><br />
      Biography : <%= f.text_area :biography %><br />
      Admin?    : <%= f.check_box :admin %><br />
      <%= f.submit %>
    <% end %>

There, the argument is a symbol or string with the name of the object the form is about.

The form builder acts as a regular form helper that somehow carries the model. Thus, the idea is that

    <%= f.text_field :first_name %>

gets expanded to

    <%= text_field :person, :first_name %>

The rightmost argument to `form_for` is an optional hash of options:

- `:url` - The URL the form is submitted to. It takes the same fields you pass to `url_for` or `link_to`. In particular you may pass here a named route directly as well. Defaults to the current action.

- `:namespace` - A namespace for your form to ensure uniqueness of id attributes on form elements. The namespace attribute will be prefixed with underscore on the generated HTML id.

- `:html` - Optional HTML attributes for the form tag.

Also note that `form_for` doesn’t create an exclusive scope. It’s still possible to use both the stand-alone FormHelper methods and methods from FormTagHelper. For example:

    <%= form_for @person do |f| %>
      First name: <%= f.text_field :first_name %>
      Last name : <%= f.text_field :last_name %>
      Biography : <%= text_area :person, :biography %>
      Admin?    : <%= check_box_tag "person[admin]", @person.company.admin? %>
      <%= f.submit %>
    <% end %>

This also works for the methods in FormOptionHelper and DateHelper that are designed to work with an object as base, like FormOptionHelper#collection_select and ActionView::Helpers::DateHelper#datetime_select.

### Resource-oriented style¶ ↑

As we said above, in addition to manually configuring the `form_for` call, you can rely on automated resource identification, which will use the conventions and named routes of that approach. This is the preferred way to use `form_for` nowadays.

For example, if `@post` is an existing record you want to edit

    <%= form_for @post do |f| %>
      ...
    <% end %>

is equivalent to something like:

    <%= form_for @post, :as => :post, :url => post_path(@post), :method => :put, :html => { :class => "edit_post", :id => "edit_post_45" } do |f| %>
      ...
    <% end %>

And for new records

    <%= form_for(Post.new) do |f| %>
      ...
    <% end %>

is equivalent to something like:

    <%= form_for @post, :as => :post, :url => posts_path, :html => { :class => "new_post", :id => "new_post" } do |f| %>
      ...
    <% end %>

You can also overwrite the individual conventions, like this:

    <%= form_for(@post, :url => super_posts_path) do |f| %>
      ...
    <% end %>

You can also set the answer format, like this:

    <%= form_for(@post, :format => :json) do |f| %>
      ...
    <% end %>

If you have an object that needs to be represented as a different parameter, like a Person that acts as a Client:

    <%= form_for(@person, :as => :client) do |f| %>
      ...
    <% end %>

For namespaced routes, like `admin_post_url`:

    <%= form_for([:admin, @post]) do |f| %>
     ...
    <% end %>

If your resource has associations defined, for example, you want to add comments to the document given that the routes are set correctly:

    <%= form_for([@document, @comment]) do |f| %>
     ...
    <% end %>

Where `@document = Document.find(params[:id])` and `@comment = Comment.new`.

### Setting the method¶ ↑

You can force the form to use the full array of HTTP verbs by setting

    :method => (:get|:post|:put|:delete)

in the options hash. If the verb is not GET or POST, which are natively supported by HTML forms, the form will be set to POST and a hidden input called _method will carry the intended verb for the server to interpret.

### Unobtrusive JavaScript¶ ↑

Specifying:

    :remote => true

in the options hash creates a form that will allow the unobtrusive JavaScript drivers to modify its behavior. The expected default behavior is an XMLHttpRequest in the background instead of the regular POST arrangement, but ultimately the behavior is the choice of the JavaScript driver implementor. Even though it’s using JavaScript to serialize the form elements, the form submission will work just like a regular submission as viewed by the receiving side (all elements available in `params`).

Example:

    <%= form_for(@post, :remote => true) do |f| %>
      ...
    <% end %>

The HTML generated for this would be:

    <form action='http://www.example.com' method='post' data-remote='true'>
      <div style='margin:0;padding:0;display:inline'>
        <input name='_method' type='hidden' value='put' />
      </div>
      ...
    </form>

### Removing hidden model id’s¶ ↑

The #form_for method automatically includes the model id as a hidden field in the form. This is used to maintain the correlation between the form data and its associated model. Some ORM systems do not use IDs on nested models so in this case you want to be able to disable the hidden id.

In the following example the Post model has many Comments stored within it in a NoSQL database, thus there is no primary key for comments.

Example:

    <%= form_for(@post) do |f| %>
      <% f.fields_for(:comments, :include_id => false) do |cf| %>
        ...
      <% end %>
    <% end %>

### Customized form builders¶ ↑

You can also build forms using a customized FormBuilder class. Subclass FormBuilder and override or define some more helpers, then use your custom builder. For example, let’s say you made a helper to automatically add labels to form inputs.

    <%= form_for @person, :url => { :action => "create" }, :builder => LabellingFormBuilder do |f| %>
      <%= f.text_field :first_name %>
      <%= f.text_field :last_name %>
      <%= f.text_area :biography %>
      <%= f.check_box :admin %>
      <%= f.submit %>
    <% end %>

In this case, if you use this:

    <%= render f %>

The rendered template is `people/_labelling_form` and the local variable referencing the form builder is called `labelling_form`.

The custom FormBuilder class is automatically merged with the options of a nested #fields_for call, unless it’s explicitly set.

In many cases you will want to wrap the above in another helper, so you could do something like the following:

    def labelled_form_for(record_or_name_or_array, *args, &block)
      options = args.extract_options!
      form_for(record_or_name_or_array, *(args << options.merge(:builder => LabellingFormBuilder)), &block)
    end

If you don’t need to attach a form to a model instance, then check out ActionView::Helpers::FormTagHelper#form_tag.

### Form to external resources¶ ↑

When you build forms to external resources sometimes you need to set an authenticity token or just render a form without it, for example when you submit data to a payment gateway number and types of fields could be limited.

To set an authenticity token you need to pass an `:authenticity_token` parameter

    <%= form_for @invoice, :url => external_url, :authenticity_token => 'external_token' do |f|
      ...
    <% end %>

If you don’t want to an authenticity token field be rendered at all just pass `false`:

    <%= form_for @invoice, :url => external_url, :authenticity_token => false do |f|
      ...
    <% end %>

    # File lib/action_view/helpers/form_helper.rb, line 358
    def form_for(record, options = {}, &block)
      raise ArgumentError, "Missing block" unless block_given?

      options[:html] ||= {}

      case record
      when String, Symbol
        object_name = record
        object      = nil
      else
        object      = record.is_a?(Array) ? record.last : record
        object_name = options[:as] || ActiveModel::Naming.param_key(object)
        apply_form_for_options!(record, options)
      end

      options[:html][:remote] = options.delete(:remote) if options.has_key?(:remote)
      options[:html][:method] = options.delete(:method) if options.has_key?(:method)
      options[:html][:authenticity_token] = options.delete(:authenticity_token)

      builder = options[:parent_builder] = instantiate_builder(object_name, object, options, &block)
      output  = capture(builder, &block)
      default_options = builder.multipart? ? { :multipart => true } : {}
      form_tag(options.delete(:url) || {}, default_options.merge!(options.delete(:html))) { output }
    end

hidden_field(object_name, method, options = {}) click to toggle source

Returns a hidden input tag tailored for accessing a specified attribute (identified by `method`) on an object assigned to the template (identified by `object`). Additional options on the input tag can be passed as a hash with `options`. These options will be tagged onto the HTML as an HTML element attribute as in the example shown.

#### Examples¶ ↑

    hidden_field(:signup, :pass_confirm)
    # => <input type="hidden" id="signup_pass_confirm" name="signup[pass_confirm]" value="#{@signup.pass_confirm}" />

    hidden_field(:post, :tag_list)
    # => <input type="hidden" id="post_tag_list" name="post[tag_list]" value="#{@post.tag_list}" />

    hidden_field(:user, :token)
    # => <input type="hidden" id="user_token" name="user[token]" value="#{@user.token}" />

    # File lib/action_view/helpers/form_helper.rb, line 729
    def hidden_field(object_name, method, options = {})
      InstanceTag.new(object_name, method, self, options.delete(:object)).to_input_field_tag("hidden", options)
    end

label(object_name, method, content_or_options = nil, options = nil, &block) click to toggle source

Returns a label tag tailored for labelling an input field for a specified attribute (identified by `method`) on an object assigned to the template (identified by `object`). The text of label will default to the attribute name unless a translation is found in the current I18n locale (through helpers.label.<modelname>.<attribute>) or you specify it explicitly. Additional options on the label tag can be passed as a hash with `options`. These options will be tagged onto the HTML as an HTML element attribute as in the example shown, except for the `:value` option, which is designed to target labels for #radio_button tags (where the value is used in the ID of the input tag).

#### Examples¶ ↑

    label(:post, :title)
    # => <label for="post_title">Title</label>

    You can localize your labels based on model and attribute names.
    For example you can define the following in your locale (e.g. en.yml)

    helpers:
      label:
        post:
          body: "Write your entire text here"

    Which then will result in

    label(:post, :body)
    # => <label for="post_body">Write your entire text here</label>

Localization can also be based purely on the translation of the attribute-name (if you are using ActiveRecord):

    activerecord:
      attributes:
        post:
          cost: "Total cost"

    label(:post, :cost)
    # => <label for="post_cost">Total cost</label>

    label(:post, :title, "A short title")
    # => <label for="post_title">A short title</label>

    label(:post, :title, "A short title", :class => "title_label")
    # => <label for="post_title" class="title_label">A short title</label>

    label(:post, :privacy, "Public Post", :value => "public")
    # => <label for="post_privacy_public">Public Post</label>

    label(:post, :terms) do
      'Accept <a href="/terms">Terms</a>.'.html_safe
    end

    # File lib/action_view/helpers/form_helper.rb, line 657
    def label(object_name, method, content_or_options = nil, options = nil, &block)
      options ||= {}

      content_is_options = content_or_options.is_a?(Hash)
      if content_is_options || block_given?
        options.merge!(content_or_options) if content_is_options
        text = nil
      else
        text = content_or_options
      end

      InstanceTag.new(object_name, method, self, options.delete(:object)).to_label_tag(text, options, &block)
    end

number_field(object_name, method, options = {}) click to toggle source

Returns an input tag of type “number”.

#### Options¶ ↑

- Accepts same options as number_field_tag

    # File lib/action_view/helpers/form_helper.rb, line 937
    def number_field(object_name, method, options = {})
      InstanceTag.new(object_name, method, self, options.delete(:object)).to_number_field_tag("number", options)
    end

password_field(object_name, method, options = {}) click to toggle source

Returns an input tag of the “password” type tailored for accessing a specified attribute (identified by `method`) on an object assigned to the template (identified by `object`). Additional options on the input tag can be passed as a hash with `options`. These options will be tagged onto the HTML as an HTML element attribute as in the example shown.

#### Examples¶ ↑

    password_field(:login, :pass, :size => 20)
    # => <input type="password" id="login_pass" name="login[pass]" size="20" />

    password_field(:account, :secret, :class => "form_input", :value => @account.secret)
    # => <input type="password" id="account_secret" name="account[secret]" value="#{@account.secret}" class="form_input" />

    password_field(:user, :password, :onchange => "if $('user[password]').length > 30 { alert('Your password needs to be shorter!'); }")
    # => <input type="password" id="user_password" name="user[password]" onchange = "if $('user[password]').length > 30 { alert('Your password needs to be shorter!'); }"/>

    password_field(:account, :pin, :size => 20, :class => 'form_input')
    # => <input type="password" id="account_pin" name="account[pin]" size="20" class="form_input" />

    # File lib/action_view/helpers/form_helper.rb, line 711
    def password_field(object_name, method, options = {})
      InstanceTag.new(object_name, method, self, options.delete(:object)).to_input_field_tag("password", { :value => nil }.merge!(options))
    end

phone_field(object_name, method, options = {})
Alias for: telephone_field
radio_button(object_name, method, tag_value, options = {}) click to toggle source

Returns a radio button tag for accessing a specified attribute (identified by `method`) on an object assigned to the template (identified by `object`). If the current value of `method` is `tag_value` the radio button will be checked.

To force the radio button to be checked pass `:checked => true` in the `options` hash. You may pass HTML options there as well.

#### Examples¶ ↑

    # Let's say that @post.category returns "rails":
    radio_button("post", "category", "rails")
    radio_button("post", "category", "java")
    # => <input type="radio" id="post_category_rails" name="post[category]" value="rails" checked="checked" />
    #    <input type="radio" id="post_category_java" name="post[category]" value="java" />

    radio_button("user", "receive_newsletter", "yes")
    radio_button("user", "receive_newsletter", "no")
    # => <input type="radio" id="user_receive_newsletter_yes" name="user[receive_newsletter]" value="yes" />
    #    <input type="radio" id="user_receive_newsletter_no" name="user[receive_newsletter]" value="no" checked="checked" />

    # File lib/action_view/helpers/form_helper.rb, line 862
    def radio_button(object_name, method, tag_value, options = {})
      InstanceTag.new(object_name, method, self, options.delete(:object)).to_radio_button_tag(tag_value, options)
    end

range_field(object_name, method, options = {}) click to toggle source

Returns an input tag of type “range”.

#### Options¶ ↑

- Accepts same options as range_field_tag

    # File lib/action_view/helpers/form_helper.rb, line 945
    def range_field(object_name, method, options = {})
      InstanceTag.new(object_name, method, self, options.delete(:object)).to_number_field_tag("range", options)
    end

search_field(object_name, method, options = {}) click to toggle source

Returns an input of type “search” for accessing a specified attribute (identified by `method`) on an object assigned to the template (identified by `object_name`). Inputs of type “search” may be styled differently by some browsers.

#### Examples¶ ↑

    search_field(:user, :name)
    # => <input id="user_name" name="user[name]" size="30" type="search" />
    search_field(:user, :name, :autosave => false)
    # => <input autosave="false" id="user_name" name="user[name]" size="30" type="search" />
    search_field(:user, :name, :results => 3)
    # => <input id="user_name" name="user[name]" results="3" size="30" type="search" />
    #  Assume request.host returns "www.example.com"
    search_field(:user, :name, :autosave => true)
    # => <input autosave="com.example.www" id="user_name" name="user[name]" results="10" size="30" type="search" />
    search_field(:user, :name, :onsearch => true)
    # => <input id="user_name" incremental="true" name="user[name]" onsearch="true" size="30" type="search" />
    search_field(:user, :name, :autosave => false, :onsearch => true)
    # => <input autosave="false" id="user_name" incremental="true" name="user[name]" onsearch="true" size="30" type="search" />
    search_field(:user, :name, :autosave => true, :onsearch => true)
    # => <input autosave="com.example.www" id="user_name" incremental="true" name="user[name]" onsearch="true" results="10" size="30" type="search" />

    # File lib/action_view/helpers/form_helper.rb, line 888
    def search_field(object_name, method, options = {})
      options = options.stringify_keys

      if options["autosave"]
        if options["autosave"] == true
          options["autosave"] = request.host.split(".").reverse.join(".")
        end
        options["results"] ||= 10
      end

      if options["onsearch"]
        options["incremental"] = true unless options.has_key?("incremental")
      end

      InstanceTag.new(object_name, method, self, options.delete("object")).to_input_field_tag("search", options)
    end

telephone_field(object_name, method, options = {}) click to toggle source

Returns a #text_field of type “tel”.

    telephone_field("user", "phone")
    # => <input id="user_phone" name="user[phone]" size="30" type="tel" />

    # File lib/action_view/helpers/form_helper.rb, line 910
    def telephone_field(object_name, method, options = {})
      InstanceTag.new(object_name, method, self, options.delete(:object)).to_input_field_tag("tel", options)
    end

Also aliased as: phone_field
text_area(object_name, method, options = {}) click to toggle source

Returns a textarea opening and closing tag set tailored for accessing a specified attribute (identified by `method`) on an object assigned to the template (identified by `object`). Additional options on the input tag can be passed as a hash with `options`.

#### Examples¶ ↑

    text_area(:post, :body, :cols => 20, :rows => 40)
    # => <textarea cols="20" rows="40" id="post_body" name="post[body]">
    #      #{@post.body}
    #    </textarea>

    text_area(:comment, :text, :size => "20x30")
    # => <textarea cols="20" rows="30" id="comment_text" name="comment[text]">
    #      #{@comment.text}
    #    </textarea>

    text_area(:application, :notes, :cols => 40, :rows => 15, :class => 'app_input')
    # => <textarea cols="40" rows="15" id="application_notes" name="application[notes]" class="app_input">
    #      #{@application.notes}
    #    </textarea>

    text_area(:entry, :body, :size => "20x20", :disabled => 'disabled')
    # => <textarea cols="20" rows="20" id="entry_body" name="entry[body]" disabled="disabled">
    #      #{@entry.body}
    #    </textarea>

    # File lib/action_view/helpers/form_helper.rb, line 778
    def text_area(object_name, method, options = {})
      InstanceTag.new(object_name, method, self, options.delete(:object)).to_text_area_tag(options)
    end

text_field(object_name, method, options = {}) click to toggle source

Returns an input tag of the “text” type tailored for accessing a specified attribute (identified by `method`) on an object assigned to the template (identified by `object`). Additional options on the input tag can be passed as a hash with `options`. These options will be tagged onto the HTML as an HTML element attribute as in the example shown.

#### Examples¶ ↑

    text_field(:post, :title, :size => 20)
    # => <input type="text" id="post_title" name="post[title]" size="20" value="#{@post.title}" />

    text_field(:post, :title, :class => "create_input")
    # => <input type="text" id="post_title" name="post[title]" value="#{@post.title}" class="create_input" />

    text_field(:session, :user, :onchange => "if $('session[user]').value == 'admin' { alert('Your login can not be admin!'); }")
    # => <input type="text" id="session_user" name="session[user]" value="#{@session.user}" onchange = "if $('session[user]').value == 'admin' { alert('Your login can not be admin!'); }"/>

    text_field(:snippet, :code, :size => 20, :class => 'code_input')
    # => <input type="text" id="snippet_code" name="snippet[code]" size="20" value="#{@snippet.code}" class="code_input" />

    # File lib/action_view/helpers/form_helper.rb, line 689
    def text_field(object_name, method, options = {})
      InstanceTag.new(object_name, method, self, options.delete(:object)).to_input_field_tag("text", options)
    end

url_field(object_name, method, options = {}) click to toggle source

Returns a #text_field of type “url”.

    url_field("user", "homepage")
    # => <input id="user_homepage" size="30" name="user[homepage]" type="url" />

    # File lib/action_view/helpers/form_helper.rb, line 920
    def url_field(object_name, method, options = {})
      InstanceTag.new(object_name, method, self, options.delete(:object)).to_input_field_tag("url", options)
    end