require 'cgi'
require 'action_view/helpers/date_helper'
require 'action_view/helpers/tag_helper'
module ActionView
module Helpers
# Form helpers are designed to make working with models much easier than just standard html elements. These helpers
# provide a set of methods for creating forms based on your models. Each helper deals with a different type of data.
# Instead of creating the html elements manually, you ask the helpers to create the form element. When the form is
# submitted i.e. when the user hits the submit button, the form elements will be bundled into the params object and
# passed back to the controller.
#
# There are two types of form helper, those that specifically work with the attributes on models, and those that don't.
# First, an example of a form generated for a login page that doesn't deal with model attributes:
#
# <% form_tag :controller => 'sessions', :action => 'new' do -%>
# <%= text_field_tag 'login' %>
# <%= password_field_tag 'password' %>
#
# <%= submit_tag 'Log in' %>
# <% end -%>
#
# This would generate the following html:
#
# <form action="/sessions/new" method="post">
# <input id="login" name="login" type="text" />
# <input id="password" name="password" type="password" />
#
# <input name="commit" type="submit" value="Log in" />
# </form>
#
# The params object created for this would look like:
#
# {"commit"=>"Log in", "action"=>"create", "controller"=>"sessions", "login"=>"some_user", "password"=>"some_pass"}
#
# Note how the params are not nested when creating a form this way.
#
# An example that specifically deals with a person object:
#
# # Note: a @person variable will have been created in the controller and populated with data
# # e.g. @person = Person.find(1)
# <% form_for :person, @person, :url => { :action => "update" } do |f| %>
# <%= f.text_field :first_name %>
# <%= f.text_field :last_name %>
# <%= submit_tag 'Update' %>
# <% end %>
#
# The html generated for this would be:
#
# <form action="/persons/update" method="post">
# <input id="person_first_name" name="person[first_name]" size="30" type="text" />
# <input id="person_last_name" name="person[last_name]" size="30" type="text" />
# <input name="commit" type="submit" value="Update" />
# </form>
#
# The params object created when this form is submitted would look like:
#
# {"action"=>"create", "controller"=>"sessions", "person"=>{"first_name"=>"William", "last_name"=>"Smith"}}
#
# The form_for method generates a form based on a method, in our example if the @person object had contained any
# values they would have been set in the form (this is how edit forms are created). Notice how the params hash
# has a nested 'person' value, which can therefore be accessed with params[:person] in the controller.
#
# If the object name contains square brackets the id for the object will be inserted. Example:
#
# <%= text_field "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 are also methods for helping to build form tags in link:classes/ActionView/Helpers/FormOptionsHelper.html,
# link:classes/ActionView/Helpers/DateHelper.html, and link:classes/ActionView/Helpers/ActiveRecordHelper.html
module FormHelper
# Creates a form and a scope around a specific model object, which is then used as a base for questioning about
# values for the fields. Examples:
#
# <% form_for :person, @person, :url => { :action => "update" } do |f| %>
# First name: <%= f.text_field :first_name %>
# Last name : <%= f.text_field :last_name %>
# Biography : <%= f.text_area :biography %>
# Admin? : <%= f.check_box :admin %>
# <% end %>
#
# Worth noting is that the form_for tag is called in a ERb evaluation block, not an ERb output block. So that's <tt><% %></tt>,
# not <tt><%= %></tt>. Also worth noting is that form_for yields a form_builder object, in this example as f, which emulates
# the API for the stand-alone FormHelper methods, but without the object name. So instead of <tt>text_field :person, :name</tt>,
# you get away with <tt>f.text_field :name</tt>.
#
# That in itself is a modest increase in comfort. The big news is that form_for allows us to more easily escape the instance
# variable convention, so while the stand-alone approach would require <tt>text_field :person, :name, :object => person</tt>
# to work with local variables instead of instance ones, the form_for calls remain the same. You simply declare once with
# <tt>:person, person</tt> and all subsequent field calls save <tt>:person</tt> and <tt>:object => person</tt>.
#
# 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. Example:
#
# <% form_for :person, @person, :url => { :action => "update" } 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? %>
# <% end %>
#
# Note: This also works for the methods in FormOptionHelper and DateHelper that are designed to work with an object as base.
# Like collection_select and datetime_select.
#
# Html attributes for the form tag can be given as :html => {...}. Example:
#
# <% form_for :person, @person, :html => {:id => 'person_form'} do |f| %>
# ...
# <% end %>
#
# You can also build forms using a customized FormBuilder class. Subclass FormBuilder and override or define some more helpers,
# then use your custom builder like so:
#
# <% form_for :person, @person, :url => { :action => "update" }, :builder => LabellingFormBuilder do |f| %>
# <%= f.text_field :first_name %>
# <%= f.text_field :last_name %>
# <%= text_area :person, :biography %>
# <%= check_box_tag "person[admin]", @person.company.admin? %>
# <% end %>
#
# In many cases you will want to wrap the above in another helper, such as:
#
# def labelled_form_for(name, object, options, &proc)
# form_for(name, object, options.merge(:builder => LabellingFormBuiler), &proc)
# end
#
def form_for(object_name, *args, &proc)
raise ArgumentError, "Missing block" unless block_given?
options = args.last.is_a?(Hash) ? args.pop : {}
concat(form_tag(options.delete(:url) || {}, options.delete(:html) || {}), proc.binding)
fields_for(object_name, *(args << options), &proc)
concat('</form>', proc.binding)
end
# 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. Example:
#
# <% form_for :person, @person, :url => { :action => "update" } do |person_form| %>
# First name: <%= person_form.text_field :first_name %>
# Last name : <%= person_form.text_field :last_name %>
#
# <% fields_for :permission, @person.permission do |permission_fields| %>
# Admin? : <%= permission_fields.check_box :admin %>
# <% end %>
# <% end %>
#
# Note: This also works for the methods in FormOptionHelper and DateHelper that are designed to work with an object as base.
# Like collection_select and datetime_select.
def fields_for(object_name, *args, &block)
raise ArgumentError, "Missing block" unless block_given?
options = args.last.is_a?(Hash) ? args.pop : {}
object = args.first
builder = options[:builder] || ActionView::Base.default_form_builder
yield builder.new(object_name, object, self, options, block)
end
# 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 (call, result):
# text_field(:post, :title, :size => 20)
# <input type="text" id="post_title" name="post[title]" size="20" value="#{@post.title}" />
def text_field(object_name, method, options = {})
InstanceTag.new(object_name, method, self, nil, options.delete(:object)).to_input_field_tag("text", options)
end
# Works just like text_field, but returns an input tag of the "password" type instead.
def password_field(object_name, method, options = {})
InstanceTag.new(object_name, method, self, nil, options.delete(:object)).to_input_field_tag("password", options)
end
# Works just like text_field, but returns an input tag of the "hidden" type instead.
def hidden_field(object_name, method, options = {})
InstanceTag.new(object_name, method, self, nil, options.delete(:object)).to_input_field_tag("hidden", options)
end
# Works just like text_field, but returns an input tag of the "file" type instead, which won't have a default value.
def file_field(object_name, method, options = {})
InstanceTag.new(object_name, method, self, nil, options.delete(:object)).to_input_field_tag("file", options)
end
# 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+.
#
# Example (call, result):
# text_area("post", "body", "cols" => 20, "rows" => 40)
# <textarea cols="20" rows="40" id="post_body" name="post[body]">
# #{@post.body}
# </textarea>
def text_area(object_name, method, options = {})
InstanceTag.new(object_name, method, self, nil, options.delete(:object)).to_text_area_tag(options)
end
# Returns a checkbox tag tailored for accessing a specified attribute (identified by +method+) on an object
# assigned to the template (identified by +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. Usually unchecked checkboxes don't post anything.
# We work around this problem by adding a hidden value with the same name as the checkbox.
#
# Example (call, result). Imagine that @post.validated? returns 1:
# check_box("post", "validated")
# <input type="checkbox" id="post_validate" name="post[validated]" value="1" checked="checked" />
# <input name="post[validated]" type="hidden" value="0" />
#
# Example (call, result). Imagine that @puppy.gooddog returns "no":
# check_box("puppy", "gooddog", {}, "yes", "no")
# <input type="checkbox" id="puppy_gooddog" name="puppy[gooddog]" value="yes" />
# <input name="puppy[gooddog]" type="hidden" value="no" />
def check_box(object_name, method, options = {}, checked_value = "1", unchecked_value = "0")
InstanceTag.new(object_name, method, self, nil, options.delete(:object)).to_check_box_tag(options, checked_value, unchecked_value)
end
# 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. Additional options on the input tag can be passed as a
# hash with +options+.
# Example (call, result). Imagine that @post.category returns "rails":
# radio_button("post", "category", "rails")
# radio_button("post", "category", "java")
# <input type="radio" id="post_category" name="post[category]" value="rails" checked="checked" />
# <input type="radio" id="post_category" name="post[category]" value="java" />
#
def radio_button(object_name, method, tag_value, options = {})
InstanceTag.new(object_name, method, self, nil, options.delete(:object)).to_radio_button_tag(tag_value, options)
end
end
class InstanceTag #:nodoc:
include Helpers::TagHelper
attr_reader :method_name, :object_name
DEFAULT_FIELD_OPTIONS = { "size" => 30 }.freeze unless const_defined?(:DEFAULT_FIELD_OPTIONS)
DEFAULT_RADIO_OPTIONS = { }.freeze unless const_defined?(:DEFAULT_RADIO_OPTIONS)
DEFAULT_TEXT_AREA_OPTIONS = { "cols" => 40, "rows" => 20 }.freeze unless const_defined?(:DEFAULT_TEXT_AREA_OPTIONS)
DEFAULT_DATE_OPTIONS = { :discard_type => true }.freeze unless const_defined?(:DEFAULT_DATE_OPTIONS)
def initialize(object_name, method_name, template_object, local_binding = nil, object = nil)
@object_name, @method_name = object_name.to_s.dup, method_name.to_s.dup
@template_object, @local_binding = template_object, local_binding
@object = object
if @object_name.sub!(/\[\]$/,"")
if object ||= @template_object.instance_variable_get("@#{Regexp.last_match.pre_match}") and object.respond_to?(:id_before_type_cast)
@auto_index = object.id_before_type_cast
else
raise ArgumentError, "object[] naming but object param and @object var don't exist or don't respond to id_before_type_cast: #{object.inspect}"
end
end
end
def to_input_field_tag(field_type, options = {})
options = options.stringify_keys
options["size"] ||= options["maxlength"] || DEFAULT_FIELD_OPTIONS["size"]
options = DEFAULT_FIELD_OPTIONS.merge(options)
if field_type == "hidden"
options.delete("size")
end
options["type"] = field_type
options["value"] ||= value_before_type_cast(object) unless field_type == "file"
add_default_name_and_id(options)
tag("input", options)
end
def to_radio_button_tag(tag_value, options = {})
options = DEFAULT_RADIO_OPTIONS.merge(options.stringify_keys)
options["type"] = "radio"
options["value"] = tag_value
if options.has_key?("checked")
cv = options.delete "checked"
checked = cv == true || cv == "checked"
else
checked = self.class.radio_button_checked?(value(object), tag_value)
end
options["checked"] = "checked" if checked
pretty_tag_value = tag_value.to_s.gsub(/\s/, "_").gsub(/\W/, "").downcase
options["id"] ||= defined?(@auto_index) ?
"#{@object_name}_#{@auto_index}_#{@method_name}_#{pretty_tag_value}" :
"#{@object_name}_#{@method_name}_#{pretty_tag_value}"
add_default_name_and_id(options)
tag("input", options)
end
def to_text_area_tag(options = {})
options = DEFAULT_TEXT_AREA_OPTIONS.merge(options.stringify_keys)
add_default_name_and_id(options)
if size = options.delete("size")
options["cols"], options["rows"] = size.split("x")
end
content_tag("textarea", html_escape(options.delete('value') || value_before_type_cast(object)), options)
end
def to_check_box_tag(options = {}, checked_value = "1", unchecked_value = "0")
options = options.stringify_keys
options["type"] = "checkbox"
options["value"] = checked_value
if options.has_key?("checked")
cv = options.delete "checked"
checked = cv == true || cv == "checked"
else
checked = self.class.check_box_checked?(value(object), checked_value)
end
options["checked"] = "checked" if checked
add_default_name_and_id(options)
tag("input", options) << tag("input", "name" => options["name"], "type" => "hidden", "value" => unchecked_value)
end
def to_date_tag()
defaults = DEFAULT_DATE_OPTIONS.dup
date = value(object) || Date.today
options = Proc.new { |position| defaults.merge(:prefix => "#{@object_name}[#{@method_name}(#{position}i)]") }
html_day_select(date, options.call(3)) +
html_month_select(date, options.call(2)) +
html_year_select(date, options.call(1))
end
def to_boolean_select_tag(options = {})
options = options.stringify_keys
add_default_name_and_id(options)
value = value(object)
tag_text = "<select"
tag_text << tag_options(options)
tag_text << "><option value=\"false\""
tag_text << " selected" if value == false
tag_text << ">False</option><option value=\"true\""
tag_text << " selected" if value
tag_text << ">True</option></select>"
end
def to_content_tag(tag_name, options = {})
content_tag(tag_name, value(object), options)
end
def object
@object || @template_object.instance_variable_get("@#{@object_name}")
end
def value(object)
self.class.value(object, @method_name)
end
def value_before_type_cast(object)
self.class.value_before_type_cast(object, @method_name)
end
class << self
def value(object, method_name)
object.send method_name unless object.nil?
end
def value_before_type_cast(object, method_name)
unless object.nil?
object.respond_to?(method_name + "_before_type_cast") ?
object.send(method_name + "_before_type_cast") :
object.send(method_name)
end
end
def check_box_checked?(value, checked_value)
case value
when TrueClass, FalseClass
value
when NilClass
false
when Integer
value != 0
when String
value == checked_value
else
value.to_i != 0
end
end
def radio_button_checked?(value, checked_value)
value.to_s == checked_value.to_s
end
end
private
def add_default_name_and_id(options)
if options.has_key?("index")
options["name"] ||= tag_name_with_index(options["index"])
options["id"] ||= tag_id_with_index(options["index"])
options.delete("index")
elsif defined?(@auto_index)
options["name"] ||= tag_name_with_index(@auto_index)
options["id"] ||= tag_id_with_index(@auto_index)
else
options["name"] ||= tag_name + (options.has_key?('multiple') ? '[]' : '')
options["id"] ||= tag_id
end
end
def tag_name
"#{@object_name}[#{@method_name}]"
end
def tag_name_with_index(index)
"#{@object_name}[#{index}][#{@method_name}]"
end
def tag_id
"#{sanitized_object_name}_#{@method_name}"
end
def tag_id_with_index(index)
"#{sanitized_object_name}_#{index}_#{@method_name}"
end
def sanitized_object_name
@object_name.gsub(/[^-a-zA-Z0-9:.]/, "_").sub(/_$/, "")
end
end
class FormBuilder #:nodoc:
# The methods which wrap a form helper call.
class_inheritable_accessor :field_helpers
self.field_helpers = (FormHelper.instance_methods - ['form_for'])
attr_accessor :object_name, :object, :options
def initialize(object_name, object, template, options, proc)
@object_name, @object, @template, @options, @proc = object_name, object, template, options, proc
end
(field_helpers - %w(check_box radio_button fields_for)).each do |selector|
src = <<-end_src
def #{selector}(method, options = {})
@template.send(#{selector.inspect}, @object_name, method, options.merge(:object => @object))
end
end_src
class_eval src, __FILE__, __LINE__
end
def fields_for(name, *args, &block)
name = "#{object_name}[#{name}]"
@template.fields_for(name, *args, &block)
end
def check_box(method, options = {}, checked_value = "1", unchecked_value = "0")
@template.check_box(@object_name, method, options.merge(:object => @object), checked_value, unchecked_value)
end
def radio_button(method, tag_value, options = {})
@template.radio_button(@object_name, method, tag_value, options.merge(:object => @object))
end
def error_message_on(method, prepend_text = "", append_text = "", css_class = "formError")
@template.error_message_on(@object_name, method, prepend_text, append_text, css_class)
end
def error_messages(options = {})
@template.error_messages_for(@object_name, options)
end
def submit(value = "Save changes", options = {})
@template.submit_tag(value, options.reverse_merge(:id => "#{object_name}_submit"))
end
end
end
class Base
cattr_accessor :default_form_builder
self.default_form_builder = ::ActionView::Helpers::FormBuilder
end
end
