diff options
Diffstat (limited to 'actionview/lib/action_view/helpers/form_helper.rb')
| -rw-r--r-- | actionview/lib/action_view/helpers/form_helper.rb | 1942 |
1 files changed, 1942 insertions, 0 deletions
diff --git a/actionview/lib/action_view/helpers/form_helper.rb b/actionview/lib/action_view/helpers/form_helper.rb new file mode 100644 index 0000000000..c4371dc705 --- /dev/null +++ b/actionview/lib/action_view/helpers/form_helper.rb @@ -0,0 +1,1942 @@ +require 'cgi' +require 'action_view/helpers/date_helper' +require 'action_view/helpers/tag_helper' +require 'action_view/helpers/form_tag_helper' +require 'action_view/helpers/active_model_helper' +require 'action_view/model_naming' +require 'active_support/core_ext/module/attribute_accessors' +require 'active_support/core_ext/hash/slice' +require 'active_support/core_ext/string/output_safety' +require 'active_support/core_ext/string/inflections' + +module ActionView + # = Action View Form Helpers + module Helpers + # Form helpers are designed to make working with resources much easier + # compared to using vanilla HTML. + # + # Typically, a form designed to create or update a resource reflects the + # identity of the resource in several ways: (i) the url that the form is + # sent to (the form element's +action+ attribute) should result in a request + # being routed to the appropriate controller action (with the appropriate <tt>:id</tt> + # parameter in the case of an existing resource), (ii) input fields should + # be named in such a way that in the controller their values appear in the + # appropriate places within the +params+ hash, and (iii) for an existing record, + # when the form is initially displayed, input fields corresponding to attributes + # of the resource should show the current values of those attributes. + # + # In Rails, this is usually achieved by creating the form using +form_for+ and + # a number of related helper methods. +form_for+ generates an appropriate <tt>form</tt> + # tag and yields a form builder object that knows the model the form is about. + # Input fields are created by calling methods defined on the form builder, which + # means they are able to generate the appropriate names and default values + # corresponding to the model attributes, as well as convenient IDs, 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 <tt>PeopleController#new</tt> action, <tt>@person</tt>, and + # in the view template pass that object 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"> + # <input name="authenticity_token" type="hidden" value="NrOp5bsjoLRuK8IW5+dQEYjKGUJDe7TQoZVvq95Wteg=" /> + # <label for="person_first_name">First name</label>: + # <input id="person_first_name" name="person[first_name]" type="text" /><br /> + # + # <label for="person_last_name">Last name</label>: + # <input id="person_last_name" name="person[last_name]" 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 <tt>params[:person]</tt> with the person attributes + # set in the form. That hash is ready to be passed to <tt>Person.create</tt>: + # + # 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 <tt>@person</tt> 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"> + # <input name="_method" type="hidden" value="patch" /> + # <input name="authenticity_token" type="hidden" value="NrOp5bsjoLRuK8IW5+dQEYjKGUJDe7TQoZVvq95Wteg=" /> + # <label for="person_first_name">First name</label>: + # <input id="person_first_name" name="person[first_name]" type="text" value="John" /><br /> + # + # <label for="person_last_name">Last name</label>: + # <input id="person_last_name" name="person[last_name]" 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 <tt>@person</tt>. + # 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 <tt>params[:person]</tt>, ready to be + # passed to <tt>Person#update</tt>: + # + # if @person.update(params[:person]) + # # success + # else + # # error handling + # end + # + # That's how you typically work with resources. + module FormHelper + extend ActiveSupport::Concern + + include FormTagHelper + include UrlHelper + include ModelNaming + + # Creates a form that allows the user to create or update the attributes + # of a specific model object. + # + # The method can be used in several slightly different ways, depending on + # how much you wish to rely on Rails to infer automatically from the model + # how the form should be constructed. For a generic model object, a form + # can be created by passing +form_for+ a string or symbol representing + # the object we are concerned with: + # + # <%= 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 %> + # + # The variable +f+ yielded to the block is a FormBuilder object that + # incorporates the knowledge about the model object represented by + # <tt>:person</tt> passed to +form_for+. Methods defined on the FormBuilder + # are used to generate fields bound to this model. Thus, for example, + # + # <%= f.text_field :first_name %> + # + # will get expanded to + # + # <%= text_field :person, :first_name %> + # which results in an HTML <tt><input></tt> tag whose +name+ attribute is + # <tt>person[first_name]</tt>. This means that when the form is submitted, + # the value entered by the user will be available in the controller as + # <tt>params[:person][:first_name]</tt>. + # + # For fields generated in this way using the FormBuilder, + # if <tt>:person</tt> also happens to be the name of an instance variable + # <tt>@person</tt>, the default value of the field shown when the form is + # initially displayed (e.g. in the situation where you are editing an + # existing record) will be the value of the corresponding attribute of + # <tt>@person</tt>. + # + # The rightmost argument to +form_for+ is an + # optional hash of options - + # + # * <tt>:url</tt> - The URL the form is to be submitted to. This may be + # represented in the same way as values passed to +url_for+ or +link_to+. + # So for example you may use a named route directly. When the model is + # represented by a string or symbol, as in the example above, if the + # <tt>:url</tt> option is not specified, by default the form will be + # sent back to the current url (We will describe below an alternative + # resource-oriented usage of +form_for+ in which the URL does not need + # to be specified explicitly). + # * <tt>:namespace</tt> - 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. + # * <tt>:method</tt> - The method to use when submitting the form, usually + # either "get" or "post". If "patch", "put", "delete", or another verb + # is used, a hidden input with name <tt>_method</tt> is added to + # simulate the verb over post. + # * <tt>:authenticity_token</tt> - Authenticity token to use in the form. + # Use only if you need to pass custom authenticity token string, or to + # not add authenticity_token field at all (by passing <tt>false</tt>). + # Remote forms may omit the embedded authenticity token by setting + # <tt>config.action_view.embed_authenticity_token_in_remote_forms = false</tt>. + # This is helpful when you're fragment-caching the form. Remote forms + # get the authenticity token from the <tt>meta</tt> tag, so embedding is + # unnecessary unless you support browsers without JavaScript. + # * <tt>:remote</tt> - If set to true, will allow the Unobtrusive + # JavaScript drivers to control the submit behavior. By default this + # behavior is an ajax submit. + # * <tt>:enforce_utf8</tt> - If set to false, a hidden input with name + # utf8 is not output. + # * <tt>:html</tt> - 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]", "1", @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 DateHelper#datetime_select. + # + # === #form_for with a model object + # + # In the examples above, the object to be created or edited was + # represented by a symbol passed to +form_for+, and we noted that + # a string can also be used equivalently. It is also possible, however, + # to pass a model object itself to +form_for+. For example, if <tt>@post</tt> + # is an existing record you wish to edit, you can create the form using + # + # <%= form_for @post do |f| %> + # ... + # <% end %> + # + # This behaves in almost the same way as outlined previously, with a + # couple of small exceptions. First, the prefix used to name the input + # elements within the form (hence the key that denotes them in the +params+ + # hash) is actually derived from the object's _class_, e.g. <tt>params[:post]</tt> + # if the object's class is +Post+. However, this can be overwritten using + # the <tt>:as</tt> option, e.g. - + # + # <%= form_for(@person, as: :client) do |f| %> + # ... + # <% end %> + # + # would result in <tt>params[:client]</tt>. + # + # Secondly, the field values shown when the form is initially displayed + # are taken from the attributes of the object passed to +form_for+, + # regardless of whether the object is an instance + # variable. So, for example, if we had a _local_ variable +post+ + # representing an existing record, + # + # <%= form_for post do |f| %> + # ... + # <% end %> + # + # would produce a form with fields whose initial state reflect the current + # values of the attributes of +post+. + # + # === Resource-oriented style + # + # In the examples just shown, although not indicated explicitly, we still + # need to use the <tt>:url</tt> option in order to specify where the + # form is going to be sent. However, further simplification is possible + # if the record passed to +form_for+ is a _resource_, i.e. it corresponds + # to a set of RESTful routes, e.g. defined using the +resources+ method + # in <tt>config/routes.rb</tt>. In this case Rails will simply infer the + # appropriate URL from the record itself. For example, + # + # <%= form_for @post do |f| %> + # ... + # <% end %> + # + # is then equivalent to something like: + # + # <%= form_for @post, as: :post, url: post_path(@post), method: :patch, html: { class: "edit_post", id: "edit_post_45" } do |f| %> + # ... + # <% end %> + # + # And for a new record + # + # <%= 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 %> + # + # However you can still overwrite individual conventions, such as: + # + # <%= 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 %> + # + # 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 <tt>@document = Document.find(params[:id])</tt> and + # <tt>@comment = Comment.new</tt>. + # + # === Setting the method + # + # You can force the form to use the full array of HTTP verbs by setting + # + # method: (:get|:post|:patch|: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 <tt>params</tt>). + # + # 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'> + # <input name='_method' type='hidden' value='patch' /> + # ... + # </form> + # + # === Setting HTML options + # + # You can set data attributes directly by passing in a data hash, but all other HTML options must be wrapped in + # the HTML key. Example: + # + # <%= form_for(@post, data: { behavior: "autosave" }, html: { name: "go" }) do |f| %> + # ... + # <% end %> + # + # The HTML generated for this would be: + # + # <form action='http://www.example.com' method='post' data-behavior='autosave' name='go'> + # <input name='_method' type='hidden' value='patch' /> + # ... + # </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 <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 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 + # 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 <tt>:authenticity_token</tt> 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 <tt>false</tt>: + # + # <%= form_for @invoice, url: external_url, authenticity_token: false do |f| + # ... + # <% end %> + def form_for(record, options = {}, &block) + raise ArgumentError, "Missing block" unless block_given? + html_options = options[:html] ||= {} + + case record + when String, Symbol + object_name = record + object = nil + else + object = record.is_a?(Array) ? record.last : record + raise ArgumentError, "First argument in form cannot contain nil or be empty" unless object + object_name = options[:as] || model_name_from_record_or_class(object).param_key + apply_form_for_options!(record, object, options) + end + + html_options[:data] = options.delete(:data) if options.has_key?(:data) + html_options[:remote] = options.delete(:remote) if options.has_key?(:remote) + html_options[:method] = options.delete(:method) if options.has_key?(:method) + html_options[:enforce_utf8] = options.delete(:enforce_utf8) if options.has_key?(:enforce_utf8) + html_options[:authenticity_token] = options.delete(:authenticity_token) + + builder = instantiate_builder(object_name, object, options) + output = capture(builder, &block) + html_options[:multipart] ||= builder.multipart? + + html_options = html_options_for_form(options[:url] || {}, html_options) + form_tag_with_body(html_options, output) + end + + def apply_form_for_options!(record, object, options) #:nodoc: + object = convert_to_model(object) + + as = options[:as] + namespace = options[:namespace] + action, method = object.respond_to?(:persisted?) && object.persisted? ? [:edit, :patch] : [:new, :post] + options[:html].reverse_merge!( + class: as ? "#{action}_#{as}" : dom_class(object, action), + id: (as ? [namespace, action, as] : [namespace, dom_id(object, action)]).compact.join("_").presence, + method: method + ) + + options[:url] ||= if options.key?(:format) + polymorphic_path(record, format: options.delete(:format)) + else + polymorphic_path(record, {}) + end + end + private :apply_form_for_options! + + # 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. + # + # Although the usage and purpose of +fields_for+ is similar to +form_for+'s, + # its method signature is slightly different. Like +form_for+, it yields + # a FormBuilder object associated with a particular model object to a block, + # and within the block allows methods to be called on the builder to + # generate fields associated with the model object. Fields may reflect + # a model object in two ways - how they are named (hence how submitted + # values appear within the +params+ hash in the controller) and what + # default values are shown when the form the fields appear in is first + # displayed. In order for both of these features to be specified independently, + # both an object name (represented by either a symbol or string) and the + # object itself can be passed to the method separately - + # + # <%= form_for @person 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 %> + # + # <%= person_form.submit %> + # <% end %> + # + # In this case, the checkbox field will be represented by an HTML +input+ + # tag with the +name+ attribute <tt>permission[admin]</tt>, and the submitted + # value will appear in the controller as <tt>params[:permission][:admin]</tt>. + # If <tt>@person.permission</tt> is an existing record with an attribute + # +admin+, the initial state of the checkbox when first displayed will + # reflect the value of <tt>@person.permission.admin</tt>. + # + # Often this can be simplified by passing just the name of the model + # object to +fields_for+ - + # + # <%= fields_for :permission do |permission_fields| %> + # Admin?: <%= permission_fields.check_box :admin %> + # <% end %> + # + # ...in which case, if <tt>:permission</tt> also happens to be the name of an + # instance variable <tt>@permission</tt>, the initial state of the input + # field will reflect the value of that variable's attribute <tt>@permission.admin</tt>. + # + # Alternatively, you can pass just the model object itself (if the first + # argument isn't a string or symbol +fields_for+ will realize that the + # name has been omitted) - + # + # <%= fields_for @person.permission do |permission_fields| %> + # Admin?: <%= permission_fields.check_box :admin %> + # <% end %> + # + # and +fields_for+ will derive the required name of the field from the + # _class_ of the model object, e.g. if <tt>@person.permission</tt>, is + # of class +Permission+, the field will still be named <tt>permission[admin]</tt>. + # + # 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 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>_destroy</tt> 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 <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 + # + # Note that the <tt>projects_attributes=</tt> writer method is in fact + # required for fields_for to correctly identify <tt>:projects</tt> 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 %> + # + # 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>_destroy</tt> + # 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 %> + # + # When a collection is used you might want to know the index of each + # object into the array. For this purpose, the <tt>index</tt> method + # is available in the FormBuilder object. + # + # <%= form_for @person do |person_form| %> + # ... + # <%= person_form.fields_for :projects do |project_fields| %> + # Project #<%= project_fields.index %> + # ... + # <% end %> + # ... + # <% end %> + # + # Note that fields_for will automatically generate a hidden field + # to store the ID of the record. There are circumstances where this + # hidden field is not needed and you can pass <tt>include_id: false</tt> + # to prevent fields_for from rendering it automatically. + def fields_for(record_name, record_object = nil, options = {}, &block) + builder = instantiate_builder(record_name, record_object, options) + capture(builder, &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 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 <tt>:value</tt> 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 + # # => <label for="post_terms">Accept <a href="/terms">Terms</a>.</label> + def label(object_name, method, content_or_options = nil, options = nil, &block) + Tags::Label.new(object_name, method, self, content_or_options, options).render(&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 + # 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 ($('#session_user').val() === 'admin') { alert('Your login cannot be admin!'); }") + # # => <input type="text" id="session_user" name="session[user]" value="#{@session.user}" onchange="if ($('#session_user').val() === 'admin') { alert('Your login cannot 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" /> + def text_field(object_name, method, options = {}) + Tags::TextField.new(object_name, method, self, options).render + 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. For security reasons this field is blank by default; pass in a value via +options+ if this is not desired. + # + # ==== 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 ($('#user_password').val().length > 30) { alert('Your password needs to be shorter!'); }") + # # => <input type="password" id="user_password" name="user[password]" onchange="if ($('#user_password').val().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" /> + def password_field(object_name, method, options = {}) + Tags::PasswordField.new(object_name, method, self, options).render + 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) + # # => <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}" /> + def hidden_field(object_name, method, options = {}) + Tags::HiddenField.new(object_name, method, self, options).render + end + + # 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 <tt>multipart/form-data</tt>. + # + # ==== Options + # * Creates standard HTML attributes for the tag. + # * <tt>:disabled</tt> - If set to true, the user will not be able to use this input. + # * <tt>:multiple</tt> - If set to true, *in most updated browsers* the user will be allowed to select multiple files. + # * <tt>:accept</tt> - If set to one or multiple mime-types, the user will be suggested a filter when choosing a file. You still need to set up model validations. + # + # ==== Examples + # file_field(:user, :avatar) + # # => <input type="file" id="user_avatar" name="user[avatar]" /> + # + # file_field(:post, :image, :multiple => true) + # # => <input type="file" id="post_image" name="post[image]" multiple="true" /> + # + # file_field(:post, :attached, accept: 'text/html') + # # => <input accept="text/html" type="file" id="post_attached" name="post[attached]" /> + # + # file_field(:post, :image, accept: 'image/png,image/gif,image/jpeg') + # # => <input type="file" id="post_image" name="post[image]" accept="image/png,image/gif,image/jpeg" /> + # + # file_field(:attachment, :file, class: 'file_input') + # # => <input type="file" id="attachment_file" name="attachment[file]" class="file_input" /> + def file_field(object_name, method, options = {}) + Tags::FileField.new(object_name, method, self, options).render + 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) + # # => <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> + def text_area(object_name, method, options = {}) + Tags::TextArea.new(object_name, method, self, options).render + 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(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. + # + # # Let's say that @post.validated? is 1: + # check_box("post", "validated") + # # => <input name="post[validated]" type="hidden" value="0" /> + # # <input checked="checked" 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" /> + def check_box(object_name, method, options = {}, checked_value = "1", unchecked_value = "0") + Tags::CheckBox.new(object_name, method, self, checked_value, unchecked_value, options).render + 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. + # + # 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. + # + # # 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" /> + def radio_button(object_name, method, tag_value, options = {}) + Tags::RadioButton.new(object_name, method, self, tag_value, options).render + end + + # Returns a text_field of type "color". + # + # color_field("car", "color") + # # => <input id="car_color" name="car[color]" type="color" value="#000000" /> + def color_field(object_name, method, options = {}) + Tags::ColorField.new(object_name, method, self, options).render + end + + # 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. + # + # search_field(:user, :name) + # # => <input id="user_name" name="user[name]" type="search" /> + # search_field(:user, :name, autosave: false) + # # => <input autosave="false" id="user_name" name="user[name]" type="search" /> + # search_field(:user, :name, results: 3) + # # => <input id="user_name" name="user[name]" results="3" 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" type="search" /> + # search_field(:user, :name, onsearch: true) + # # => <input id="user_name" incremental="true" name="user[name]" onsearch="true" type="search" /> + # search_field(:user, :name, autosave: false, onsearch: true) + # # => <input autosave="false" id="user_name" incremental="true" name="user[name]" onsearch="true" 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" type="search" /> + def search_field(object_name, method, options = {}) + Tags::SearchField.new(object_name, method, self, options).render + end + + # Returns a text_field of type "tel". + # + # telephone_field("user", "phone") + # # => <input id="user_phone" name="user[phone]" type="tel" /> + # + def telephone_field(object_name, method, options = {}) + Tags::TelField.new(object_name, method, self, options).render + end + # aliases telephone_field + alias phone_field telephone_field + + # Returns a text_field of type "date". + # + # date_field("user", "born_on") + # # => <input id="user_born_on" name="user[born_on]" type="date" /> + # + # The default value is generated by trying to call "to_date" + # on the object's value, which makes it behave as expected for instances + # of DateTime and ActiveSupport::TimeWithZone. You can still override that + # by passing the "value" option explicitly, e.g. + # + # @user.born_on = Date.new(1984, 1, 27) + # date_field("user", "born_on", value: "1984-05-12") + # # => <input id="user_born_on" name="user[born_on]" type="date" value="1984-05-12" /> + # + # You can create values for the "min" and "max" attributes by passing + # instances of Date or Time to the options hash. + # + # date_field("user", "born_on", min: Date.today) + # # => <input id="user_born_on" name="user[born_on]" type="date" min="2014-05-20" /> + # + # Alternatively, you can pass a String formatted as an ISO8601 date as the + # values for "min" and "max." + # + # date_field("user", "born_on", min: "2014-05-20") + # # => <input id="user_born_on" name="user[born_on]" type="date" min="2014-05-20" /> + # + def date_field(object_name, method, options = {}) + Tags::DateField.new(object_name, method, self, options).render + end + + # Returns a text_field of type "time". + # + # The default value is generated by trying to call +strftime+ with "%T.%L" + # on the objects's value. It is still possible to override that + # by passing the "value" option. + # + # === Options + # * Accepts same options as time_field_tag + # + # === Example + # time_field("task", "started_at") + # # => <input id="task_started_at" name="task[started_at]" type="time" /> + # + # You can create values for the "min" and "max" attributes by passing + # instances of Date or Time to the options hash. + # + # time_field("task", "started_at", min: Time.now) + # # => <input id="task_started_at" name="task[started_at]" type="time" min="01:00:00.000" /> + # + # Alternatively, you can pass a String formatted as an ISO8601 time as the + # values for "min" and "max." + # + # time_field("task", "started_at", min: "01:00:00") + # # => <input id="task_started_at" name="task[started_at]" type="time" min="01:00:00.000" /> + # + def time_field(object_name, method, options = {}) + Tags::TimeField.new(object_name, method, self, options).render + end + + # Returns a text_field of type "datetime". + # + # datetime_field("user", "born_on") + # # => <input id="user_born_on" name="user[born_on]" type="datetime" /> + # + # The default value is generated by trying to call +strftime+ with "%Y-%m-%dT%T.%L%z" + # on the object's value, which makes it behave as expected for instances + # of DateTime and ActiveSupport::TimeWithZone. + # + # @user.born_on = Date.new(1984, 1, 12) + # datetime_field("user", "born_on") + # # => <input id="user_born_on" name="user[born_on]" type="datetime" value="1984-01-12T00:00:00.000+0000" /> + # + # You can create values for the "min" and "max" attributes by passing + # instances of Date or Time to the options hash. + # + # datetime_field("user", "born_on", min: Date.today) + # # => <input id="user_born_on" name="user[born_on]" type="datetime" min="2014-05-20T00:00:00.000+0000" /> + # + # Alternatively, you can pass a String formatted as an ISO8601 datetime + # with UTC offset as the values for "min" and "max." + # + # datetime_field("user", "born_on", min: "2014-05-20T00:00:00+0000") + # # => <input id="user_born_on" name="user[born_on]" type="datetime" min="2014-05-20T00:00:00.000+0000" /> + # + def datetime_field(object_name, method, options = {}) + Tags::DatetimeField.new(object_name, method, self, options).render + end + + # Returns a text_field of type "datetime-local". + # + # datetime_local_field("user", "born_on") + # # => <input id="user_born_on" name="user[born_on]" type="datetime-local" /> + # + # The default value is generated by trying to call +strftime+ with "%Y-%m-%dT%T" + # on the object's value, which makes it behave as expected for instances + # of DateTime and ActiveSupport::TimeWithZone. + # + # @user.born_on = Date.new(1984, 1, 12) + # datetime_local_field("user", "born_on") + # # => <input id="user_born_on" name="user[born_on]" type="datetime-local" value="1984-01-12T00:00:00" /> + # + # You can create values for the "min" and "max" attributes by passing + # instances of Date or Time to the options hash. + # + # datetime_local_field("user", "born_on", min: Date.today) + # # => <input id="user_born_on" name="user[born_on]" type="datetime-local" min="2014-05-20T00:00:00.000" /> + # + # Alternatively, you can pass a String formatted as an ISO8601 datetime as + # the values for "min" and "max." + # + # datetime_local_field("user", "born_on", min: "2014-05-20T00:00:00") + # # => <input id="user_born_on" name="user[born_on]" type="datetime-local" min="2014-05-20T00:00:00.000" /> + # + def datetime_local_field(object_name, method, options = {}) + Tags::DatetimeLocalField.new(object_name, method, self, options).render + end + + # Returns a text_field of type "month". + # + # month_field("user", "born_on") + # # => <input id="user_born_on" name="user[born_on]" type="month" /> + # + # The default value is generated by trying to call +strftime+ with "%Y-%m" + # on the object's value, which makes it behave as expected for instances + # of DateTime and ActiveSupport::TimeWithZone. + # + # @user.born_on = Date.new(1984, 1, 27) + # month_field("user", "born_on") + # # => <input id="user_born_on" name="user[born_on]" type="date" value="1984-01" /> + # + def month_field(object_name, method, options = {}) + Tags::MonthField.new(object_name, method, self, options).render + end + + # Returns a text_field of type "week". + # + # week_field("user", "born_on") + # # => <input id="user_born_on" name="user[born_on]" type="week" /> + # + # The default value is generated by trying to call +strftime+ with "%Y-W%W" + # on the object's value, which makes it behave as expected for instances + # of DateTime and ActiveSupport::TimeWithZone. + # + # @user.born_on = Date.new(1984, 5, 12) + # week_field("user", "born_on") + # # => <input id="user_born_on" name="user[born_on]" type="date" value="1984-W19" /> + # + def week_field(object_name, method, options = {}) + Tags::WeekField.new(object_name, method, self, options).render + end + + # Returns a text_field of type "url". + # + # url_field("user", "homepage") + # # => <input id="user_homepage" name="user[homepage]" type="url" /> + # + def url_field(object_name, method, options = {}) + Tags::UrlField.new(object_name, method, self, options).render + end + + # Returns a text_field of type "email". + # + # email_field("user", "address") + # # => <input id="user_address" name="user[address]" type="email" /> + # + def email_field(object_name, method, options = {}) + Tags::EmailField.new(object_name, method, self, options).render + end + + # Returns an input tag of type "number". + # + # ==== Options + # * Accepts same options as number_field_tag + def number_field(object_name, method, options = {}) + Tags::NumberField.new(object_name, method, self, options).render + end + + # Returns an input tag of type "range". + # + # ==== Options + # * Accepts same options as range_field_tag + def range_field(object_name, method, options = {}) + Tags::RangeField.new(object_name, method, self, options).render + end + + private + + def instantiate_builder(record_name, record_object, options) + case record_name + when String, Symbol + object = record_object + object_name = record_name + else + object = record_name + object_name = model_name_from_record_or_class(object).param_key + end + + builder = options[:builder] || default_form_builder + builder.new(object_name, object, self, options) + end + + def default_form_builder + builder = ActionView::Base.default_form_builder + builder.respond_to?(:constantize) ? builder.constantize : builder + end + end + + # A +FormBuilder+ object is associated with a particular model object and + # allows you to generate fields associated with the model object. The + # +FormBuilder+ object is yielded when using +form_for+ or +fields_for+. + # For example: + # + # <%= form_for @person do |person_form| %> + # Name: <%= person_form.text_field :name %> + # Admin: <%= person_form.check_box :admin %> + # <% end %> + # + # In the above block, the a +FormBuilder+ object is yielded as the + # +person_form+ variable. This allows you to generate the +text_field+ + # and +check_box+ fields by specifying their eponymous methods, which + # modify the underlying template and associates the +@person+ model object + # with the form. + # + # The +FormBuilder+ object can be thought of as serving as a proxy for the + # methods in the +FormHelper+ module. This class, however, allows you to + # call methods with the model object you are building the form for. + # + # You can create your own custom FormBuilder templates by subclassing this + # class. For example: + # + # class MyFormBuilder < ActionView::Helpers::FormBuilder + # def div_radio_button(method, tag_value, options = {}) + # @template.content_tag(:div, + # @template.radio_button( + # @object_name, method, tag_value, objectify_options(options) + # ) + # ) + # end + # + # The above code creates a new method +div_radio_button+ which wraps a div + # around the new radio button. Note that when options are passed in, you + # must call +objectify_options+ in order for the model object to get + # correctly passed to the method. If +objectify_options+ is not called, + # then the newly created helper will not be linked back to the model. + # + # The +div_radio_button+ code from above can now be used as follows: + # + # <%= form_for @person, :builder => MyFormBuilder do |f| %> + # I am a child: <%= f.div_radio_button(:admin, "child") %> + # I am an adult: <%= f.div_radio_button(:admin, "adult") %> + # <% end -%> + # + # The standard set of helper methods for form building are located in the + # +field_helpers+ class attribute. + class FormBuilder + include ModelNaming + + # The methods which wrap a form helper call. + class_attribute :field_helpers + self.field_helpers = [:fields_for, :label, :text_field, :password_field, + :hidden_field, :file_field, :text_area, :check_box, + :radio_button, :color_field, :search_field, + :telephone_field, :phone_field, :date_field, + :time_field, :datetime_field, :datetime_local_field, + :month_field, :week_field, :url_field, :email_field, + :number_field, :range_field] + + attr_accessor :object_name, :object, :options + + attr_reader :multipart, :index + alias :multipart? :multipart + + def multipart=(multipart) + @multipart = multipart + + if parent_builder = @options[:parent_builder] + parent_builder.multipart = multipart + end + end + + def self._to_partial_path + @_to_partial_path ||= name.demodulize.underscore.sub!(/_builder$/, '') + end + + def to_partial_path + self.class._to_partial_path + end + + def to_model + self + end + + def initialize(object_name, object, template, options) + @nested_child_index = {} + @object_name, @object, @template, @options = object_name, object, template, options + @default_options = @options ? @options.slice(:index, :namespace) : {} + 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 + @multipart = nil + @index = options[:index] || options[:child_index] + end + + (field_helpers - [:label, :check_box, :radio_button, :fields_for, :hidden_field, :file_field]).each do |selector| + class_eval <<-RUBY_EVAL, __FILE__, __LINE__ + 1 + def #{selector}(method, options = {}) # def text_field(method, options = {}) + @template.send( # @template.send( + #{selector.inspect}, # "text_field", + @object_name, # @object_name, + method, # method, + objectify_options(options)) # objectify_options(options)) + end # end + RUBY_EVAL + 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. + # + # Although the usage and purpose of +fields_for+ is similar to +form_for+'s, + # its method signature is slightly different. Like +form_for+, it yields + # a FormBuilder object associated with a particular model object to a block, + # and within the block allows methods to be called on the builder to + # generate fields associated with the model object. Fields may reflect + # a model object in two ways - how they are named (hence how submitted + # values appear within the +params+ hash in the controller) and what + # default values are shown when the form the fields appear in is first + # displayed. In order for both of these features to be specified independently, + # both an object name (represented by either a symbol or string) and the + # object itself can be passed to the method separately - + # + # <%= form_for @person 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 %> + # + # <%= person_form.submit %> + # <% end %> + # + # In this case, the checkbox field will be represented by an HTML +input+ + # tag with the +name+ attribute <tt>permission[admin]</tt>, and the submitted + # value will appear in the controller as <tt>params[:permission][:admin]</tt>. + # If <tt>@person.permission</tt> is an existing record with an attribute + # +admin+, the initial state of the checkbox when first displayed will + # reflect the value of <tt>@person.permission.admin</tt>. + # + # Often this can be simplified by passing just the name of the model + # object to +fields_for+ - + # + # <%= fields_for :permission do |permission_fields| %> + # Admin?: <%= permission_fields.check_box :admin %> + # <% end %> + # + # ...in which case, if <tt>:permission</tt> also happens to be the name of an + # instance variable <tt>@permission</tt>, the initial state of the input + # field will reflect the value of that variable's attribute <tt>@permission.admin</tt>. + # + # Alternatively, you can pass just the model object itself (if the first + # argument isn't a string or symbol +fields_for+ will realize that the + # name has been omitted) - + # + # <%= fields_for @person.permission do |permission_fields| %> + # Admin?: <%= permission_fields.check_box :admin %> + # <% end %> + # + # and +fields_for+ will derive the required name of the field from the + # _class_ of the model object, e.g. if <tt>@person.permission</tt>, is + # of class +Permission+, the field will still be named <tt>permission[admin]</tt>. + # + # 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 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>_destroy</tt> 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 <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 + # + # Note that the <tt>projects_attributes=</tt> writer method is in fact + # required for fields_for to correctly identify <tt>:projects</tt> 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 %> + # + # 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>_destroy</tt> + # 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 %> + # + # When a collection is used you might want to know the index of each + # object into the array. For this purpose, the <tt>index</tt> method + # is available in the FormBuilder object. + # + # <%= form_for @person do |person_form| %> + # ... + # <%= person_form.fields_for :projects do |project_fields| %> + # Project #<%= project_fields.index %> + # ... + # <% end %> + # ... + # <% end %> + # + # Note that fields_for will automatically generate a hidden field + # to store the ID of the record. There are circumstances where this + # hidden field is not needed and you can pass <tt>include_id: false</tt> + # to prevent fields_for from rendering it automatically. + def fields_for(record_name, record_object = nil, fields_options = {}, &block) + fields_options, record_object = record_object, nil if record_object.is_a?(Hash) && record_object.extractable_options? + fields_options[:builder] ||= options[:builder] + fields_options[:namespace] = options[:namespace] + fields_options[:parent_builder] = self + + case record_name + when String, Symbol + if nested_attributes_association?(record_name) + return fields_for_with_nested_attributes(record_name, record_object, fields_options, block) + end + else + record_object = record_name.is_a?(Array) ? record_name.last : record_name + record_name = model_name_from_record_or_class(record_object).param_key + end + + index = if options.has_key?(:index) + options[:index] + elsif defined?(@auto_index) + self.object_name = @object_name.to_s.sub(/\[\]$/,"") + @auto_index + end + + record_name = index ? "#{object_name}[#{index}][#{record_name}]" : "#{object_name}[#{record_name}]" + fields_options[:child_index] = index + + @template.fields_for(record_name, record_object, fields_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 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 <tt>:value</tt> 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 + def label(method, text = nil, options = {}, &block) + @template.label(@object_name, method, text, objectify_options(options), &block) + 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(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. + # + # # Let's say that @post.validated? is 1: + # check_box("post", "validated") + # # => <input name="post[validated]" type="hidden" value="0" /> + # # <input checked="checked" 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" /> + 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 + + # 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 <tt>checked: true</tt> in the + # +options+ hash. You may pass HTML options there as well. + # + # # 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" /> + def radio_button(method, tag_value, options = {}) + @template.radio_button(@object_name, method, tag_value, objectify_options(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) + # # => <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}" /> + # + def hidden_field(method, options = {}) + @emitted_hidden_id = true if method == :id + @template.hidden_field(@object_name, method, objectify_options(options)) + end + + # 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 <tt>multipart/form-data</tt>. + # + # ==== Options + # * Creates standard HTML attributes for the tag. + # * <tt>:disabled</tt> - If set to true, the user will not be able to use this input. + # * <tt>:multiple</tt> - If set to true, *in most updated browsers* the user will be allowed to select multiple files. + # * <tt>:accept</tt> - If set to one or multiple mime-types, the user will be suggested a filter when choosing a file. You still need to set up model validations. + # + # ==== Examples + # file_field(:user, :avatar) + # # => <input type="file" id="user_avatar" name="user[avatar]" /> + # + # file_field(:post, :image, :multiple => true) + # # => <input type="file" id="post_image" name="post[image]" multiple="true" /> + # + # file_field(:post, :attached, accept: 'text/html') + # # => <input accept="text/html" type="file" id="post_attached" name="post[attached]" /> + # + # file_field(:post, :image, accept: 'image/png,image/gif,image/jpeg') + # # => <input type="file" id="post_image" name="post[image]" accept="image/png,image/gif,image/jpeg" /> + # + # file_field(:attachment, :file, class: 'file_input') + # # => <input type="file" id="attachment_file" name="attachment[file]" class="file_input" /> + def file_field(method, options = {}) + self.multipart = true + @template.file_field(@object_name, method, objectify_options(options)) + end + + # Add the submit button for the given form. When no value is given, it checks + # if the object is a new resource or not to create the proper label: + # + # <%= form_for @post do |f| %> + # <%= f.submit %> + # <% end %> + # + # In the example above, if @post is a new record, it will use "Create Post" as + # submit button label, otherwise, it uses "Update Post". + # + # Those labels can be customized using I18n, under the helpers.submit key and accept + # the %{model} as translation interpolation: + # + # en: + # helpers: + # submit: + # create: "Create a %{model}" + # update: "Confirm changes to %{model}" + # + # It also searches for a key specific for the given object: + # + # en: + # helpers: + # submit: + # post: + # create: "Add %{model}" + # + def submit(value=nil, options={}) + value, options = nil, value if value.is_a?(Hash) + value ||= submit_default_value + @template.submit_tag(value, options) + end + + # Add the submit button for the given form. When no value is given, it checks + # if the object is a new resource or not to create the proper label: + # + # <%= form_for @post do |f| %> + # <%= f.button %> + # <% end %> + # + # In the example above, if @post is a new record, it will use "Create Post" as + # button label, otherwise, it uses "Update Post". + # + # Those labels can be customized using I18n, under the helpers.submit key + # (the same as submit helper) and accept the %{model} as translation interpolation: + # + # en: + # helpers: + # submit: + # create: "Create a %{model}" + # update: "Confirm changes to %{model}" + # + # It also searches for a key specific for the given object: + # + # en: + # helpers: + # submit: + # post: + # create: "Add %{model}" + # + # ==== Examples + # button("Create a post") + # # => <button name='button' type='submit'>Create post</button> + # + # button do + # content_tag(:strong, 'Ask me!') + # end + # # => <button name='button' type='submit'> + # # <strong>Ask me!</strong> + # # </button> + # + def button(value = nil, options = {}, &block) + value, options = nil, value if value.is_a?(Hash) + value ||= submit_default_value + @template.button_tag(value, options, &block) + end + + def emitted_hidden_id? + @emitted_hidden_id ||= nil + end + + private + def objectify_options(options) + @default_options.merge(options.merge(object: @object)) + end + + def submit_default_value + object = convert_to_model(@object) + key = object ? (object.persisted? ? :update : :create) : :submit + + model = if object.respond_to?(:model_name) + object.model_name.human + else + @object_name.to_s.humanize + end + + defaults = [] + defaults << :"helpers.submit.#{object_name}.#{key}" + defaults << :"helpers.submit.#{key}" + defaults << "#{key.to_s.humanize} #{model}" + + I18n.t(defaults.shift, model: model, default: defaults) + end + + def nested_attributes_association?(association_name) + @object.respond_to?("#{association_name}_attributes=") + end + + def fields_for_with_nested_attributes(association_name, association, options, block) + name = "#{object_name}[#{association_name}_attributes]" + association = convert_to_model(association) + + if association.respond_to?(:persisted?) + association = [association] if @object.send(association_name).respond_to?(:to_ary) + elsif !association.respond_to?(:to_ary) + association = @object.send(association_name) + end + + if association.respond_to?(:to_ary) + explicit_child_index = options[:child_index] + output = ActiveSupport::SafeBuffer.new + association.each do |child| + options[:child_index] = nested_child_index(name) unless explicit_child_index + output << fields_for_nested_model("#{name}[#{options[:child_index]}]", child, options, block) + end + output + elsif association + fields_for_nested_model(name, association, options, block) + end + end + + def fields_for_nested_model(name, object, fields_options, block) + object = convert_to_model(object) + emit_hidden_id = object.persisted? && fields_options.fetch(:include_id) { + options.fetch(:include_id, true) + } + + @template.fields_for(name, object, fields_options) do |f| + output = @template.capture(f, &block) + output.concat f.hidden_field(:id) if output && emit_hidden_id && !f.emitted_hidden_id? + output + end + end + + def nested_child_index(name) + @nested_child_index[name] ||= -1 + @nested_child_index[name] += 1 + end + end + end + + ActiveSupport.on_load(:action_view) do + cattr_accessor(:default_form_builder, instance_writer: false, instance_reader: false) do + ::ActionView::Helpers::FormBuilder + end + end +end |