Class: Atom::Feed

Inherits:

Object

Object
Atom::Feed

show all

Extended by:: Forwardable

Includes:: SimpleExtensions, Xml::Parseable

Defined in:: lib/atom.rb

Overview

Represents a Feed as defined by the Atom Syndication Format specification.

A feed is the top level element in an atom document. It is a container for feed level metadata and for each entry in the feed.

This supports pagination as defined in RFC 5005, see www.ietf.org/rfc/rfc5005.txt

Parsing

A feed can be parsed using the Feed.load_feed method. This method accepts a String containing a valid atom document, an IO object, or an URI to a valid atom document. For example:

# Using a File
feed = Feed.load_feed(File.open("/path/to/myfeed.atom"))

# Using a URL
feed = Feed.load_feed(URI.parse("http://example.org/afeed.atom"))

Encoding

A feed can be converted to XML using, the to_xml method that returns a valid atom document in a String.

Attributes

A feed has the following attributes:

id: A unique id for the feed.
updated: The Time the feed was updated.
title: The title of the feed.
subtitle: The subtitle of the feed.
authors: An array of Atom::Person objects that are authors of this feed.
contributors: An array of Atom::Person objects that are contributors to this feed.
generator: A Atom::Generator.
categories: A list of Atom:Category objects for the feed.
rights: A string describing the rights associated with this feed.
entries: An array of Atom::Entry objects.
links: An array of Atom:Link objects. (This is actually an Atom::Links array which is an Array with some sugar).

References

Instance Attribute Summary

Attributes included from SimpleExtensions

#simple_extensions

Instance Method Summary collapse

#each_entry(options = {}, &block) ⇒ Object

Iterates over each entry in the feed.
#first? ⇒ Boolean

Return true if this is the first feed in a paginated set.
#initialize(o = {}) {|_self| ... } ⇒ Feed constructor

Initialize a Feed.
#last? ⇒ Boolean

Returns true if this is the last feed in a paginated set.
#reload!(opts = {}) ⇒ Object

Reloads the feed by fetching the self uri.

Methods included from SimpleExtensions

#[]

Methods included from Xml::Parseable

#==, #accessor_name, #current_node_is?, included, #next_node_is?, #parse, #to_xml

Constructor Details

#initialize(o = {}) {|_self| ... } ⇒ `Feed`

Initialize a Feed.

This will also yield itself, so a feed can be constructed like this:

feed = Feed.new do |feed|
  feed.title = "My Cool feed"
end

o: An XML Reader or a Hash of attributes.

Yields:

(_self)

Yield Parameters:

_self (Atom::Feed) —

the object that the method was called on

# File 'lib/atom.rb', line 459

def initialize(o = {})
  @links, @entries, @authors, @contributors, @categories = Links.new, [], [], [], []
  
  case o
  when XML::Reader
    if next_node_is?(o, 'feed', Atom::NAMESPACE)
      o.read
      parse(o)
    else
      raise ArgumentError, "XML document was missing atom:feed: #{o.read_outer_xml}"
    end
  when Hash
    o.each do |k, v|
      self.send("#{k.to_s}=", v)
    end
  else
    raise ArgumentError, "Got #{o.class} but expected a Hash or XML::Reader"
  end
  
  yield(self) if block_given?
end

Instance Method Details

#each_entry(options = {}, &block) ⇒ `Object`

Iterates over each entry in the feed.

Options

paginate: If true and the feed supports pagination this will fetch each page of the feed.
since: If a Time object is provided each_entry will iterate over all entries that were updated since that time.
user: User name for HTTP Basic Authentication.
pass: Password for HTTP Basic Authentication.

# File 'lib/atom.rb', line 507

def each_entry(options = {}, &block)
  if options[:paginate]
    since_reached = false
    feed = self
    loop do          
      feed.entries.each do |entry|
        if options[:since] && entry.updated && options[:since] > entry.updated
          since_reached = true
          break
        else
          block.call(entry)
        end
      end
      
      if since_reached || feed.next_page.nil?
        break
      else feed.next_page
        feed = feed.next_page.fetch(options)
      end
    end
  else
    self.entries.each(&block)
  end
end

#first? ⇒ `Boolean`

Return true if this is the first feed in a paginated set.

Returns:

(Boolean)



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# File 'lib/atom.rb', line 482

def first?
  links.self == links.first_page
end

#last? ⇒ `Boolean`

Returns true if this is the last feed in a paginated set.