require 'cgi' require 'action_view/helpers/date_helper' require 'action_view/helpers/tag_helper' require 'action_view/helpers/form_tag_helper' module ActionView module Helpers # Form helpers are designed to make working with models much easier compared to using just standard HTML # elements by providing a set of methods for creating forms based on your models. This helper generates the HTML # for forms, providing a method for each sort of input (e.g., text, password, select, and so on). When the form # is submitted (i.e., when the user hits the submit button or form.submit is called via JavaScript), the form inputs will be bundled into the params object and passed back to the controller. # # There are two types of form helpers: those that specifically work with model attributes and those that don't. # This helper deals with those that work with model attributes; to see an example of form helpers that don't work # with model attributes, check the ActionView::Helpers::FormTagHelper documentation. # # The core method of this helper, form_for, gives you the ability to create a form for a model instance; # for example, let's say that you have a model Person and want to create a new instance of it: # # # Note: a @person variable will have been created in the controller. # # For example: @person = Person.new # <% form_for :person, @person, :url => { :action => "create" } do |f| %> # <%= f.text_field :first_name %> # <%= f.text_field :last_name %> # <%= submit_tag 'Create' %> # <% end %> # # The HTML generated for this would be: # #
# # # #
# # If you are using a partial for your form fields, you can use this shortcut: # # <% form_for :person, @person, :url => { :action => "create" } do |f| %> # <%= render :partial => f %> # <%= submit_tag 'Create' %> # <% end %> # # This example will render the people/_form partial, setting a local variable called form which references the yielded FormBuilder. # # The params object created when this form is submitted would look like: # # {"action"=>"create", "controller"=>"persons", "person"=>{"first_name"=>"William", "last_name"=>"Smith"}} # # The params hash has a nested person value, which can therefore be accessed with params[:person] in the controller. # If were editing/updating an instance (e.g., Person.find(1) rather than Person.new in the controller), the objects # attribute values are filled into the form (e.g., the person_first_name field would have that person's first name in it). # # If the object name contains square brackets the id for the object will be inserted. For example: # # <%= text_field "person[]", "name" %> # # ...will generate the following ERb. # # # # 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... # # # # An index option may also be passed to form_for and fields_for. This automatically applies # the index to all the nested fields. # # 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 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 %>
# <%= f.label :author, 'Author' %>: # <%= f.text_field :author %>
# <% 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, :url => { :action => "update" } do |f| %> # <%= f.error_messages %> # 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 %> # # There, the first argument is a symbol or string with the name of the # object the form is about, and also the name of the instance variable the # object is stored in. # # 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 %> # # If the instance variable is not @person you can pass the actual # record as the second argument: # # <% form_for :person, person, :url => { :action => "update" } do |f| %> # ... # <% end %> # # In that case you can think # # <%= f.text_field :first_name %> # # gets expanded to # # <%= text_field :person, :first_name, :object => person %> # # You can even display error messages of the wrapped model this way: # # <%= f.error_messages %> # # In any of its variants, 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. # * :html - Optional HTML attributes for the form tag. # # Worth noting is that the +form_for+ tag is called in a ERb evaluation block, # not an ERb output block. So that's <% %>, not <%= %>. # # 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, @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 %> # # 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 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, @post, :url => post_path(@post), :html => { :method => :put, :class => "edit_post", :id => "edit_post_45" } do |f| %> # ... # <% end %> # # And for new records # # <% form_for(Post.new) do |f| %> # ... # <% end %> # # expands to # # <% form_for :post, Post.new, :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_post_path(@post)) do |f| %> # ... # <% end %> # # And for namespaced routes, like +admin_post_url+: # # <% form_for([:admin, @post]) do |f| %> # ... # <% 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, @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 this case, if you use this: # # <%= render :partial => f %> # # The rendered template is people/_labelling_form and the local variable referencing the form builder is called labelling_form. # # 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, &proc) # options = args.extract_options! # form_for(record_or_name_or_array, *(args << options.merge(:builder => LabellingFormBuilder)), &proc) # end # # If you don't need to attach a form to a model instance, then check out FormTagHelper#form_tag. def form_for(record_or_name_or_array, *args, &proc) raise ArgumentError, "Missing block" unless block_given? options = args.extract_options! case record_or_name_or_array when String, Symbol object_name = record_or_name_or_array when Array object = record_or_name_or_array.last object_name = ActionController::RecordIdentifier.singular_class_name(object) apply_form_for_options!(record_or_name_or_array, options) args.unshift object else object = record_or_name_or_array object_name = ActionController::RecordIdentifier.singular_class_name(object) apply_form_for_options!([object], options) args.unshift object end concat(form_tag(options.delete(:url) || {}, options.delete(:html) || {})) fields_for(object_name, *(args << options), &proc) concat('') end def apply_form_for_options!(object_or_array, options) #:nodoc: object = object_or_array.is_a?(Array) ? object_or_array.last : object_or_array html_options = if object.respond_to?(:new_record?) && object.new_record? { :class => dom_class(object, :new), :id => dom_id(object), :method => :post } else { :class => dom_class(object, :edit), :id => dom_id(object, :edit), :method => :put } end options[:html] ||= {} options[:html].reverse_merge!(html_options) options[:url] ||= polymorphic_path(object_or_array) 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: # # ==== Examples # <% form_for @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 @person.permission do |permission_fields| %> # Admin? : <%= permission_fields.check_box :admin %> # <% end %> # <% 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 DateHelper#datetime_select. def fields_for(record_or_name_or_array, *args, &block) raise ArgumentError, "Missing block" unless block_given? options = args.extract_options! case record_or_name_or_array when String, Symbol object_name = record_or_name_or_array object = args.first else object = record_or_name_or_array object_name = ActionController::RecordIdentifier.singular_class_name(object) end builder = options[:builder] || ActionView::Base.default_form_builder yield builder.new(object_name, object, self, options, block) end # 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 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. # # ==== Examples # label(:post, :title) # # => # # label(:post, :title, "A short title") # # => # # label(:post, :title, "A short title", :class => "title_label") # # => # def label(object_name, method, text = nil, options = {}) InstanceTag.new(object_name, method, self, options.delete(:object)).to_label_tag(text, options) 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 # text_field(:post, :title, :size => 20) # # => # # text_field(:post, :title, :class => "create_input") # # => # # text_field(:session, :user, :onchange => "if $('session[user]').value == 'admin' { alert('Your login can not be admin!'); }") # # => # # text_field(:snippet, :code, :size => 20, :class => 'code_input') # # => # def text_field(object_name, method, options = {}) InstanceTag.new(object_name, method, self, options.delete(:object)).to_input_field_tag("text", options) end # 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) # # => # # password_field(:account, :secret, :class => "form_input") # # => # # password_field(:user, :password, :onchange => "if $('user[password]').length > 30 { alert('Your password needs to be shorter!'); }") # # => # # password_field(:account, :pin, :size => 20, :class => 'form_input') # # => # def password_field(object_name, method, options = {}) InstanceTag.new(object_name, method, self, options.delete(:object)).to_input_field_tag("password", options) end # 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) # # => # # hidden_field(:post, :tag_list) # # => # # hidden_field(:user, :token) # # => def hidden_field(object_name, method, options = {}) InstanceTag.new(object_name, method, self, options.delete(:object)).to_input_field_tag("hidden", options) end # Returns an 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. # # ==== Examples # file_field(:user, :avatar) # # => # # file_field(:post, :attached, :accept => 'text/html') # # => # # file_field(:attachment, :file, :class => 'file_input') # # => # def file_field(object_name, method, options = {}) InstanceTag.new(object_name, method, self, 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+. # # ==== Examples # text_area(:post, :body, :cols => 20, :rows => 40) # # => # # text_area(:comment, :text, :size => "20x30") # # => # # text_area(:application, :notes, :cols => 40, :rows => 15, :class => 'app_input') # # => # # text_area(:entry, :body, :size => "20x20", :disabled => 'disabled') # # => def text_area(object_name, method, options = {}) InstanceTag.new(object_name, method, self, 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+). 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 a hidden field with the same name as # the checkbox after the very check box. So, 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 Rails parameters extraction always # gets the first occurrence of any given key, that works in 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. # # ==== Examples # # Let's say that @post.validated? is 1: # check_box("post", "validated") # # => # # # # # Let's say that @puppy.gooddog is "no": # check_box("puppy", "gooddog", {}, "yes", "no") # # => # # # # check_box("eula", "accepted", { :class => 'eula_check' }, "yes", "no") # # => # # # 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 # 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+. # # ==== Examples # # Let's say that @post.category returns "rails": # radio_button("post", "category", "rails") # radio_button("post", "category", "java") # # => # # # # radio_button("user", "receive_newsletter", "yes") # radio_button("user", "receive_newsletter", "no") # # => # # 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 end class InstanceTag #:nodoc: include Helpers::TagHelper, Helpers::FormTagHelper 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) def initialize(object_name, method_name, template_object, object = nil) @object_name, @method_name = object_name.to_s.dup, method_name.to_s.dup @template_object = template_object @object = object if @object_name.sub!(/\[\]$/,"") || @object_name.sub!(/\[\]\]$/,"]") if (object ||= @template_object.instance_variable_get("@#{Regexp.last_match.pre_match}")) && object.respond_to?(:to_param) @auto_index = object.to_param else raise ArgumentError, "object[] naming but object param and @object var don't exist or don't respond to to_param: #{object.inspect}" end end end def to_label_tag(text = nil, options = {}) options = options.stringify_keys name_and_id = options.dup add_default_name_and_id(name_and_id) options.delete("index") options["for"] ||= name_and_id["id"] content = (text.blank? ? nil : text.to_s) || method_name.humanize label_tag(name_and_id["id"], content, options) end def to_input_field_tag(field_type, options = {}) options = options.stringify_keys options["size"] = options["maxlength"] || DEFAULT_FIELD_OPTIONS["size"] unless options.key?("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" options["value"] &&= html_escape(options["value"]) 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) ? "#{tag_id_with_index(@auto_index)}_#{pretty_tag_value}" : "#{tag_id}_#{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") if size.respond_to?(:split) 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" => options['disabled'] && checked ? checked_value : unchecked_value) end def to_boolean_select_tag(options = {}) options = options.stringify_keys add_default_name_and_id(options) value = value(object) tag_text = "" 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}") rescue NameError # As @object_name may contain the nested syntax (item[subobject]) we # need to fallback to nil. nil 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 when Array value.include?(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}[#{sanitized_method_name}]" end def tag_name_with_index(index) "#{@object_name}[#{index}][#{sanitized_method_name}]" end def tag_id "#{sanitized_object_name}_#{sanitized_method_name}" end def tag_id_with_index(index) "#{sanitized_object_name}_#{index}_#{sanitized_method_name}" end def sanitized_object_name @sanitized_object_name ||= @object_name.gsub(/\]\[|[^-a-zA-Z0-9:.]/, "_").sub(/_$/, "") end def sanitized_method_name @sanitized_method_name ||= @method_name.sub(/\?$/,"") 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 @default_options = @options ? @options.slice(:index) : {} if @object_name.to_s.match(/\[\]$/) if object ||= @template.instance_variable_get("@#{Regexp.last_match.pre_match}") and object.respond_to?(:to_param) @auto_index = object.to_param else raise ArgumentError, "object[] naming but object param and @object var don't exist or don't respond to to_param: #{object.inspect}" end end end (field_helpers - %w(label check_box radio_button fields_for)).each do |selector| src = <<-end_src def #{selector}(method, options = {}) @template.send(#{selector.inspect}, @object_name, method, objectify_options(options)) end end_src class_eval src, __FILE__, __LINE__ end def fields_for(record_or_name_or_array, *args, &block) if options.has_key?(:index) index = "[#{options[:index]}]" elsif defined?(@auto_index) self.object_name = @object_name.to_s.sub(/\[\]$/,"") index = "[#{@auto_index}]" else index = "" end case record_or_name_or_array when String, Symbol name = "#{object_name}#{index}[#{record_or_name_or_array}]" when Array object = record_or_name_or_array.last name = "#{object_name}#{index}[#{ActionController::RecordIdentifier.singular_class_name(object)}]" args.unshift(object) else object = record_or_name_or_array name = "#{object_name}#{index}[#{ActionController::RecordIdentifier.singular_class_name(object)}]" args.unshift(object) end @template.fields_for(name, *args, &block) end def label(method, text = nil, options = {}) @template.label(@object_name, method, text, objectify_options(options)) end def check_box(method, options = {}, checked_value = "1", unchecked_value = "0") @template.check_box(@object_name, method, objectify_options(options), checked_value, unchecked_value) end def radio_button(method, tag_value, options = {}) @template.radio_button(@object_name, method, tag_value, objectify_options(options)) end def error_message_on(method, *args) @template.error_message_on(@object, method, *args) end def error_messages(options = {}) @template.error_messages_for(@object_name, objectify_options(options)) end def submit(value = "Save changes", options = {}) @template.submit_tag(value, options.reverse_merge(:id => "#{object_name}_submit")) end private def objectify_options(options) @default_options.merge(options.merge(:object => @object)) end end end class Base cattr_accessor :default_form_builder self.default_form_builder = ::ActionView::Helpers::FormBuilder end end