--- /dev/null
+require 'set'
+
+# Adds easy defaults to writing Atom feeds with the Builder template engine (this does not work on ERb or any other
+# template languages).
+module ActionView
+ module Helpers #:nodoc:
+ module AtomFeedHelper
+ # Full usage example:
+ #
+ # config/routes.rb:
+ # ActionController::Routing::Routes.draw do |map|
+ # map.resources :posts
+ # map.root :controller => "posts"
+ # end
+ #
+ # app/controllers/posts_controller.rb:
+ # class PostsController < ApplicationController::Base
+ # # GET /posts.html
+ # # GET /posts.atom
+ # def index
+ # @posts = Post.find(: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.first.created_at))
+ #
+ # for post in @posts
+ # 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.request_uri.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)
+ #
+ # for post in @posts
+ # 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
+ #
+ #
+ # atom_feed 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[: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.request_uri.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
+ 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
+ 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}"
+ 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
+
+ @xml.link(:rel => 'alternate', :type => 'text/html', :href => options[:url] || @view.polymorphic_url(record))
+
+ yield AtomBuilder.new(@xml)
+ end
+ end
+ end
+
+ end
+ end
+end
projects / depot.git / blobdiff