ActionView::Helpers::FormHelper

Provides a set of methods for working with forms and especially forms related to objects assigned to the template. The following is an example of a complete form for a person object that works for both creates and updates built with all the form helpers. The @person object was assigned by an action on the controller:

 <form action="save_person" method="post"> Name: <%= text_field "person", "name", "size" => 20 %> Password: <%= password_field "person", "password", "maxsize" => 20 %> Single?: <%= check_box "person", "single" %> Description: <%= text_area "person", "description", "cols" => 20 %> <input type="submit" value="Save"> </form> 

…is compiled to:

 <form action="save_person" method="post"> Name: <input type="text" id="person_name" name="person[name]" size="20" value="<%= @person.name %>" /> Password: <input type="password" id="person_password" name="person[password]" size="20" maxsize="20" value="<%= @person.password %>" /> Single?: <input type="checkbox" id="person_single" name="person[single]" value="1" /> Description: <textarea cols="20" rows="40" id="person_description" name="person[description]"> <%= @person.description %> </textarea> <input type="submit" value="Save"> </form> 

If the object name contains square brackets the id for the object will be inserted. Example:

 <%= textfield "person[]", "name" %> 

…becomes:

 <input type="text" id="person_<%= @person.id %>_name" name="person[<%= @person.id %>][name]" value="<%= @person.name %>" /> 

If the helper is being used to generate a repetitive sequence of similar form elements, for example in a partial used by render_collection_of_partials, the "index" option may come in handy. Example:

 <%= text_field "person", "name", "index" => 1 %> 

becomes

 <input type="text" id="person_1_name" name="person[1][name]" value="<%= @person.name %>" /> 

There’s also methods for helping to build form tags in ActionView::Helpers::FormOptionsHelper ActionView::Helpers::DateHelper and ActionView::Helpers::ActiveRecordHelper

actionpack/lib/action_view/helpers/form_helper.rb