diff options
Diffstat (limited to 'actionpack/lib/action_view/helpers/form_helper.rb')
| -rw-r--r-- | actionpack/lib/action_view/helpers/form_helper.rb | 384 |
1 files changed, 309 insertions, 75 deletions
diff --git a/actionpack/lib/action_view/helpers/form_helper.rb b/actionpack/lib/action_view/helpers/form_helper.rb index a85751c657..a59829b23f 100644 --- a/actionpack/lib/action_view/helpers/form_helper.rb +++ b/actionpack/lib/action_view/helpers/form_helper.rb @@ -5,17 +5,24 @@ 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 <tt>form.submit</tt> is called via JavaScript), the form inputs will be bundled into the <tt>params</tt> object and passed back to the controller. + # 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 <tt>form.submit</tt> is + # called via JavaScript), the form inputs will be bundled into the + # <tt>params</tt> 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. + # 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 <tt>Person</tt> and want to create a new instance of it: + # 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 + # <tt>Person</tt> 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 @@ -40,17 +47,22 @@ module ActionView # <%= submit_tag 'Create' %> # <% end %> # - # This example will render the <tt>people/_form</tt> partial, setting a local variable called <tt>form</tt> which references the yielded FormBuilder. - # - # The <tt>params</tt> object created when this form is submitted would look like: + # This example will render the <tt>people/_form</tt> partial, setting a + # local variable called <tt>form</tt> which references the yielded + # FormBuilder. The <tt>params</tt> 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 <tt>person</tt> value, which can therefore be accessed with <tt>params[:person]</tt> in the controller. - # If were editing/updating an instance (e.g., <tt>Person.find(1)</tt> rather than <tt>Person.new</tt> in the controller), the objects - # attribute values are filled into the form (e.g., the <tt>person_first_name</tt> field would have that person's first name in it). + # The params hash has a nested <tt>person</tt> value, which can therefore + # be accessed with <tt>params[:person]</tt> in the controller. If were + # editing/updating an instance (e.g., <tt>Person.find(1)</tt> rather than + # <tt>Person.new</tt> in the controller), the objects attribute values are + # filled into the form (e.g., the <tt>person_first_name</tt> 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: + # If the object name contains square brackets the id for the object will be + # inserted. For example: # # <%= text_field "person[]", "name" %> # @@ -58,8 +70,10 @@ module ActionView # # <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 <tt>render_collection_of_partials</tt>, the <tt>index</tt> option may come in handy. Example: + # If the helper is being used to generate a repetitive sequence of similar + # form elements, for example in a partial used by + # <tt>render_collection_of_partials</tt>, the <tt>index</tt> option may + # come in handy. Example: # # <%= text_field "person", "name", "index" => 1 %> # @@ -67,14 +81,17 @@ module ActionView # # <input type="text" id="person_1_name" name="person[1][name]" value="<%= @person.name %>" /> # - # An <tt>index</tt> option may also be passed to <tt>form_for</tt> and <tt>fields_for</tt>. This automatically applies - # the <tt>index</tt> to all the nested fields. + # An <tt>index</tt> option may also be passed to <tt>form_for</tt> and + # <tt>fields_for</tt>. This automatically applies the <tt>index</tt> 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 + # 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. + # 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: @@ -86,13 +103,15 @@ module ActionView # <%= f.text_field :author %><br /> # <% 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. + # 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: + # 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 %> @@ -103,8 +122,8 @@ module ActionView # <% 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. + # 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 @@ -137,17 +156,18 @@ module ActionView # In any of its variants, the rightmost argument to +form_for+ is an # optional hash of options: # - # * <tt>:url</tt> - 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. + # * <tt>:url</tt> - 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. # * <tt>:html</tt> - 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 <tt><% %></tt>, not <tt><%= %></tt>. + # 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 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: + # 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 %> @@ -156,16 +176,16 @@ module ActionView # 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. + # 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. + # 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 <tt>@post</tt> is an existing record you want to edit # @@ -205,8 +225,10 @@ module ActionView # # === 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. + # 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 %> @@ -219,16 +241,23 @@ module ActionView # # <%= render :partial => f %> # - # The rendered template is <tt>people/_labelling_form</tt> and the local variable referencing the form builder is called <tt>labelling_form</tt>. + # The rendered template is <tt>people/_labelling_form</tt> and the local + # variable referencing the form builder is called + # <tt>labelling_form</tt>. + # + # The custom FormBuilder class is automatically merged with the options + # of a nested fields_for call, unless it's explicitely set. # - # In many cases you will want to wrap the above in another helper, so you could do something like the following: + # 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. + # 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? @@ -269,10 +298,12 @@ module ActionView 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: + # 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 # - # ==== 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 %> @@ -282,20 +313,166 @@ module ActionView # <% 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: + # ...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 + # ...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. + # 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. + # + # === 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 <tt>:address</tt> is called + # <tt>address_attributes=</tt>. + # + # 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 + # <tt>address</tt> reader method and responds to the + # <tt>address_attributes=</tt> 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, :url => { :action => "update" } 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 <tt>:allow_destroy</tt> 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 <tt>_delete</tt> parameter, + # with a value that evaluates to +true+, you will destroy the associated + # model (eg. 1, '1', true, or 'true'): + # + # <% form_for @person, :url => { :action => "update" } do |person_form| %> + # ... + # <% person_form.fields_for :address do |address_fields| %> + # ... + # Delete: <%= address_fields.check_box :_delete %> + # <% end %> + # <% end %> + # + # ==== One-to-many + # + # Consider a Person class which returns an _array_ of Project instances + # from the <tt>projects</tt> reader method and responds to the + # <tt>projects_attributes=</tt> writer method: + # + # class Person + # def projects + # [@project1, @project2] + # end + # + # def projects_attributes=(attributes) + # # Process the attributes hash + # end + # 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, :url => { :action => "update" } 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, :url => { :action => "update" } 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 %> + # + # 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 <tt>:allow_destroy</tt> + # 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 <tt>_delete</tt> + # parameter with a value that evaluates to +true+ + # (eg. 1, '1', true, or 'true'): + # + # <% form_for @person, :url => { :action => "update" } do |person_form| %> + # ... + # <% person_form.fields_for :projects do |project_fields| %> + # Delete: <%= project_fields.check_box :_delete %> + # <% end %> + # <% end %> def fields_for(record_or_name_or_array, *args, &block) raise ArgumentError, "Missing block" unless block_given? options = args.extract_options! @@ -451,7 +628,7 @@ module ActionView # # 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 + # 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 # @@ -459,12 +636,15 @@ module ActionView # # 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. + # 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 mimick 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 @@ -475,22 +655,26 @@ module ActionView # <% end %> # # because parameter name repetition is precisely what Rails seeks to distinguish - # the elements of the array. + # 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 type="checkbox" id="post_validated" name="post[validated]" value="1" /> - # # <input name="post[validated]" type="hidden" value="0" /> + # # => <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 type="checkbox" id="puppy_gooddog" name="puppy[gooddog]" value="yes" /> - # # <input name="puppy[gooddog]" type="hidden" value="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 type="checkbox" class="eula_check" id="eula_accepted" name="eula[accepted]" value="yes" /> - # # <input name="eula[accepted]" type="hidden" value="no" /> + # # => <input name="eula[accepted]" type="hidden" value="no" /> + # # <input type="checkbox" class="eula_check" id="eula_accepted" name="eula[accepted]" value="yes" /> # 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) @@ -498,8 +682,10 @@ module ActionView # 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+. + # radio button will be checked. + # + # To force the radio button to be checked pass <tt>:checked => true</tt> in the + # +options+ hash. You may pass HTML options there as well. # # ==== Examples # # Let's say that @post.category returns "rails": @@ -605,7 +791,9 @@ module ActionView 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) + hidden = tag("input", "name" => options["name"], "type" => "hidden", "value" => options['disabled'] && checked ? checked_value : unchecked_value) + checkbox = tag("input", options) + hidden + checkbox end def to_boolean_select_tag(options = {}) @@ -758,9 +946,18 @@ module ActionView index = "" end + if options[:builder] + args << {} unless args.last.is_a?(Hash) + args.last[:builder] ||= options[:builder] + end + case record_or_name_or_array when String, Symbol - name = "#{object_name}#{index}[#{record_or_name_or_array}]" + if nested_attributes_association?(record_or_name_or_array) + return fields_for_with_nested_attributes(record_or_name_or_array, args, block) + else + name = "#{object_name}#{index}[#{record_or_name_or_array}]" + end when Array object = record_or_name_or_array.last name = "#{object_name}#{index}[#{ActionController::RecordIdentifier.singular_class_name(object)}]" @@ -802,6 +999,43 @@ module ActionView def objectify_options(options) @default_options.merge(options.merge(:object => @object)) end + + def nested_attributes_association?(association_name) + @object.respond_to?("#{association_name}_attributes=") + end + + def fields_for_with_nested_attributes(association_name, args, block) + name = "#{object_name}[#{association_name}_attributes]" + association = @object.send(association_name) + explicit_object = args.first if args.first.respond_to?(:new_record?) + + if association.is_a?(Array) + children = explicit_object ? [explicit_object] : association + explicit_child_index = args.last[:child_index] if args.last.is_a?(Hash) + + children.map do |child| + fields_for_nested_model("#{name}[#{explicit_child_index || nested_child_index}]", child, args, block) + end.join + else + fields_for_nested_model(name, explicit_object || association, args, block) + end + end + + def fields_for_nested_model(name, object, args, block) + if object.new_record? + @template.fields_for(name, object, *args, &block) + else + @template.fields_for(name, object, *args) do |builder| + @template.concat builder.hidden_field(:id) + block.call(builder) + end + end + end + + def nested_child_index + @nested_child_index ||= -1 + @nested_child_index += 1 + end end end @@ -809,4 +1043,4 @@ module ActionView cattr_accessor :default_form_builder self.default_form_builder = ::ActionView::Helpers::FormBuilder end -end +end
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