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Diffstat (limited to 'actionview/lib/action_view/helpers/atom_feed_helper.rb')
| -rw-r--r-- | actionview/lib/action_view/helpers/atom_feed_helper.rb | 203 |
1 files changed, 203 insertions, 0 deletions
diff --git a/actionview/lib/action_view/helpers/atom_feed_helper.rb b/actionview/lib/action_view/helpers/atom_feed_helper.rb new file mode 100644 index 0000000000..42b1dd8933 --- /dev/null +++ b/actionview/lib/action_view/helpers/atom_feed_helper.rb @@ -0,0 +1,203 @@ +require 'set' + +module ActionView + # = Action View Atom Feed Helpers + module Helpers + module AtomFeedHelper + # Adds easy defaults to writing Atom feeds with the Builder template engine (this does not work on ERB or any other + # template languages). + # + # Full usage example: + # + # config/routes.rb: + # Basecamp::Application.routes.draw do + # resources :posts + # root to: "posts#index" + # end + # + # app/controllers/posts_controller.rb: + # class PostsController < ApplicationController::Base + # # GET /posts.html + # # GET /posts.atom + # def index + # @posts = Post.all + # + # respond_to do |format| + # format.html + # format.atom + # end + # end + # end + # + # app/views/posts/index.atom.builder: + # atom_feed do |feed| + # feed.title("My great blog!") + # feed.updated(@posts[0].created_at) if @posts.length > 0 + # + # @posts.each do |post| + # feed.entry(post) do |entry| + # entry.title(post.title) + # entry.content(post.body, type: 'html') + # + # entry.author do |author| + # author.name("DHH") + # end + # end + # end + # end + # + # The options for atom_feed are: + # + # * <tt>:language</tt>: Defaults to "en-US". + # * <tt>:root_url</tt>: The HTML alternative that this feed is doubling for. Defaults to / on the current host. + # * <tt>:url</tt>: The URL for this feed. Defaults to the current URL. + # * <tt>:id</tt>: The id for this feed. Defaults to "tag:#{request.host},#{options[:schema_date]}:#{request.fullpath.split(".")[0]}" + # * <tt>:schema_date</tt>: The date at which the tag scheme for the feed was first used. A good default is the year you + # created the feed. See http://feedvalidator.org/docs/error/InvalidTAG.html for more information. If not specified, + # 2005 is used (as an "I don't care" value). + # * <tt>:instruct</tt>: Hash of XML processing instructions in the form {target => {attribute => value, }} or {target => [{attribute => value, }, ]} + # + # Other namespaces can be added to the root element: + # + # app/views/posts/index.atom.builder: + # atom_feed({'xmlns:app' => 'http://www.w3.org/2007/app', + # 'xmlns:openSearch' => 'http://a9.com/-/spec/opensearch/1.1/'}) do |feed| + # feed.title("My great blog!") + # feed.updated((@posts.first.created_at)) + # feed.tag!(openSearch:totalResults, 10) + # + # @posts.each do |post| + # feed.entry(post) do |entry| + # entry.title(post.title) + # entry.content(post.body, type: 'html') + # entry.tag!('app:edited', Time.now) + # + # entry.author do |author| + # author.name("DHH") + # end + # end + # end + # end + # + # The Atom spec defines five elements (content rights title subtitle + # summary) which may directly contain xhtml content if type: 'xhtml' + # is specified as an attribute. If so, this helper will take care of + # the enclosing div and xhtml namespace declaration. Example usage: + # + # entry.summary type: 'xhtml' do |xhtml| + # xhtml.p pluralize(order.line_items.count, "line item") + # xhtml.p "Shipped to #{order.address}" + # xhtml.p "Paid by #{order.pay_type}" + # end + # + # + # <tt>atom_feed</tt> yields an +AtomFeedBuilder+ instance. Nested elements yield + # an +AtomBuilder+ instance. + def atom_feed(options = {}, &block) + if options[:schema_date] + options[:schema_date] = options[:schema_date].strftime("%Y-%m-%d") if options[:schema_date].respond_to?(:strftime) + else + options[:schema_date] = "2005" # The Atom spec copyright date + end + + xml = options.delete(:xml) || eval("xml", block.binding) + xml.instruct! + if options[:instruct] + options[:instruct].each do |target,attrs| + if attrs.respond_to?(:keys) + xml.instruct!(target, attrs) + elsif attrs.respond_to?(:each) + attrs.each { |attr_group| xml.instruct!(target, attr_group) } + end + end + end + + feed_opts = {"xml:lang" => options[:language] || "en-US", "xmlns" => 'http://www.w3.org/2005/Atom'} + feed_opts.merge!(options).reject!{|k,v| !k.to_s.match(/^xml/)} + + xml.feed(feed_opts) do + xml.id(options[:id] || "tag:#{request.host},#{options[:schema_date]}:#{request.fullpath.split(".")[0]}") + xml.link(:rel => 'alternate', :type => 'text/html', :href => options[:root_url] || (request.protocol + request.host_with_port)) + xml.link(:rel => 'self', :type => 'application/atom+xml', :href => options[:url] || request.url) + + yield AtomFeedBuilder.new(xml, self, options) + end + end + + class AtomBuilder #:nodoc: + XHTML_TAG_NAMES = %w(content rights title subtitle summary).to_set + + def initialize(xml) + @xml = xml + end + + private + # Delegate to xml builder, first wrapping the element in a xhtml + # namespaced div element if the method and arguments indicate + # that an xhtml_block? is desired. + def method_missing(method, *arguments, &block) + if xhtml_block?(method, arguments) + @xml.__send__(method, *arguments) do + @xml.div(:xmlns => 'http://www.w3.org/1999/xhtml') do |xhtml| + block.call(xhtml) + end + end + else + @xml.__send__(method, *arguments, &block) + end + end + + # True if the method name matches one of the five elements defined + # in the Atom spec as potentially containing XHTML content and + # if type: 'xhtml' is, in fact, specified. + def xhtml_block?(method, arguments) + if XHTML_TAG_NAMES.include?(method.to_s) + last = arguments.last + last.is_a?(Hash) && last[:type].to_s == 'xhtml' + end + end + end + + class AtomFeedBuilder < AtomBuilder #:nodoc: + def initialize(xml, view, feed_options = {}) + @xml, @view, @feed_options = xml, view, feed_options + end + + # Accepts a Date or Time object and inserts it in the proper format. If nil is passed, current time in UTC is used. + def updated(date_or_time = nil) + @xml.updated((date_or_time || Time.now.utc).xmlschema) + end + + # Creates an entry tag for a specific record and prefills the id using class and id. + # + # Options: + # + # * <tt>:published</tt>: Time first published. Defaults to the created_at attribute on the record if one such exists. + # * <tt>:updated</tt>: Time of update. Defaults to the updated_at attribute on the record if one such exists. + # * <tt>:url</tt>: The URL for this entry. Defaults to the polymorphic_url for the record. + # * <tt>:id</tt>: The ID for this entry. Defaults to "tag:#{@view.request.host},#{@feed_options[:schema_date]}:#{record.class}/#{record.id}" + # * <tt>:type</tt>: The TYPE for this entry. Defaults to "text/html". + def entry(record, options = {}) + @xml.entry do + @xml.id(options[:id] || "tag:#{@view.request.host},#{@feed_options[:schema_date]}:#{record.class}/#{record.id}") + + if options[:published] || (record.respond_to?(:created_at) && record.created_at) + @xml.published((options[:published] || record.created_at).xmlschema) + end + + if options[:updated] || (record.respond_to?(:updated_at) && record.updated_at) + @xml.updated((options[:updated] || record.updated_at).xmlschema) + end + + type = options.fetch(:type, 'text/html') + + @xml.link(:rel => 'alternate', :type => type, :href => options[:url] || @view.polymorphic_url(record)) + + yield AtomBuilder.new(@xml) + end + end + end + + end + end +end |