[Developers] Another Ruby API

[Chris Eppstein]

Hello again,

I received some excellent feedback yesterday and was able to  
incorporate it into the code today, along with some significant  
refactoring and improved documentation. If you're interested please  
check out the most recent code:
http://freebaseapi.rubyforge.org/svn/trunk/freebase/

or read the docs at:
http://freebaseapi.rubyforge.org/svn/trunk/freebase/rdoc/index.html

New Features:
No need to call Freebase::Type.define('/music/artist') before  
accessing Freebase::Types::Music::Artist (thanks to pat allan for this  
suggestion and code examples)
Ability to add custom methods to instances of Freebase types using a  
mixin and naming conventions.
Support for nested queries to retrieve multiple levels of associations  
in a single query

Open Questions/Concerns:
:fb_object => true should be added to the subquery whenever sub- 
querying an association so that a distinction can be drawn for the  
following differences in validation logic between object types and  
core types:
objects have multi-valued types, core types do not and you may not  
query a core type with [] you have to use null.
values of core types do not have an id and you may not specify 'id' :  
null in the query of a core type.
In both of these cases, the validation seems arbitrarily enforced;  
returning ['/type/text'] and 'id':null back respectively are in line  
with the other behaviors of the system, in my estimation.
I'm getting nulls from collections associations from Artist -> Album  
and from Album -> Track. I understand the null names problem now and  
am handling that appropriately per the recommendations in my new  
query. But I don't understand why a null would be returned as an  
element of an array. Please let me know whether to begin searching for  
a code defect on my end.

Thanks,
Chris

The code example again using the latest api:
# Usage:
#  ./script/runner vendor/plugins/freebase/examples/albums.rb "The  
Police"

# add these methods to the Track class
module Freebase::Mixins::Music
   module Track
     def formatted_length
       "#{self.length.to_i / 60}:#{sprintf("%02i", self.length.to_i %  
60)}"
     end
   end
end


artist = Freebase::Types::Music::Artist.find(:first,
   :conditions => {
     :name => {:value => ARGV[0], :lang => {:name => "English"}},
     :album => [{
       :fb_object => true,
       :name => {:value => nil, :lang => {:name => "English"}},
       :release_date => nil,
       :track => [{
         :fb_object => true,
         :length => nil,
         :name => {:value => nil, :lang => {:name => "English"}}
       }]
     }]
   }
)

artist.albums.each_with_index do |album, i|
   next unless album # XXX I don't know why I'm getting random nils  
here.
   puts "#{i+1}) #{album.name} (#{album.release_date || '?'})"
   album.tracks.compact.each_with_index do |track, j|
       puts "\tT#{j+1}. #{track.name || '???'}  
(#{track.formatted_length})"
   end
end


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