xml_mapper

Declarative mapping of XML files to ruby attributes

Example XML

Black on Both Sides Extended Edition 1999 1999-10-12 de true Mos Def 1212 Mos Def DJ Premier Fear Not of Man 1 1 de Hip Hop Album Version 2 1 Mos Def DJ Premier at

Example Mapper

require "xml_mapper"
require "date"

class MyMapper < XmlMapper
text :title, :version_title                             # 1:1 - maps xpaths title and version_title to attribute keys
integer :released_in                                    # converts value to an integer
text :country, :after_map => :upcase                    # calls after_map method on extracted value if value responds to the method
text :released_on, :after_map => :parse_date            # calls after_map method defined in Mapper class when value does not respond
boolean :allows_streaming                               # maps 1, Y, y, yes, true => true, 0, N, n, no, false => false

within :artist do
  text :name => :artist_name                            # adds mapping for xpath "artist/name"
  integer :id => :artist_id
end

many "contributions/*" => :contributions do             # use the name of xml nodes for mappings
  node_name :role                                       # map name of xml node to :role
  inner_text :name                                      # map inner_text of xml node to :name
end

many "tracks/track" => :tracks do                       # maps xpath "tracks/track" to array with key :tracks
  attribute :code => :isrc                              # map xml attribute "code" to :isrc
  text :title => :track_title
  text :version_title
  integer :number => :track_number
  integer :disk => :disk_number
  exists :explicit_lyrics                               # checks if a node with the xpath exists
  not_exists "not_streamable_in/country[text()='de']" => :allows_streaming

  text :performer => { :contributions => :performer }   # assigns to content at xpath :performer to attributes[:contributions][:performer]
  text :producer => { :contributions => :producer }     # assigns to content at xpath :performer to attributes[:contributions][:producer]
end

after_map do                                                    # is called after attributes are extracted, self references the extracted attributes
  self[:tracks_count] = self[:tracks].length
  self[:xml_path] = self.xml_path                               # lets you access the xml_path when called with attributes_from_xml_path
  self[:other_tracks_count] = self.node.search("track").count   # lets you access the current xml node (in this case the whole doc)
end

# to be used for after_map callbacks
def parse_date(date_string)
  Date.parse(date_string)
end
end

How to call

  • MyMapper.attributes_from_xml(xml)
  • MyMapper.attributes_from_xml_path(xml)

Output

{ :title=>"Black on Both Sides", :allows_streaming=>true, :version_title=>"Extended Edition", :tracks=>[ { :track_title=>"Fear Not of Man", :allows_streaming=>false, :track_number=>1, :version_title=>nil, :disk_number=>1, :explicit_lyrics=>true, :contributions=>:producer=>nil, :isrc=>"1234" }, { :track_title=>"Hip Hop", :allows_streaming=>true, :track_number=>2, :version_title=>"Album Version", :disk_number=>1, :explicit_lyrics=>false, :contributions=>Def", :producer=>"DJ Premier", :isrc=>"2345" } ], :tracks_count=>2, :released_in=>1999, :released_on=>#<Date: 4902927/2,0,2299161>, :artist_name=>"Mos Def", :contributions=>[ Def", :role=>"artist", Premier", :role=>"producer" ] :artist_id=>1212, :country=>"DE" }

Contributing to xml_mapper

  • Check out the latest master to make sure the feature hasn't been implemented or the bug hasn't been fixed yet
  • Check out the issue tracker to make sure someone already hasn't requested it and/or contributed it
  • Fork the project
  • Start a feature/bugfix branch
  • Commit and push until you are happy with your contribution
  • Make sure to add tests for it. This is important so I don't break it in a future version unintentionally.
  • Please try not to mess with the Rakefile, version, or history. If you want to have your own version, or is otherwise necessary, that is fine, but please isolate to its own commit so I can cherry-pick around it.

Copyright (c) 2010 Tobias Schwab (Dynport GmbH).

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.