palmergs / lc_classification

Gem for converting Library of Congress classification strings into descriptions

LcClassification

LcClassification is a simple lookup gem for returning categories from Library of Congress classification strings. The basic format is AA###.#### where a one or two letter prefix determines the broad category and numbers break it out into more specific subcategories.

The categories in this gem are parsed from a text file originally found here: [http://archive.org/stream/LcClassificationA-z/lc_class.txt].

Installation

Add this line to your application's Gemfile:

gem 'lc_classification'

And then execute:

$ bundle

Or install it yourself as:

$ gem install lc_classification

Usage

Because the gem reads a text file on initialization it is recommended that it be instantiated once (perhaps wrapped as a Singleton) if it is going to be used multiple time.

# reads copy of file in data/library-of-congress-classification.txt by default
lookup = LcClassification::Lookup.new
node = lookup.find('AC903')
node.description #> "Pamphlet Collections"
node.parent.description #> "Collections of monographs, essays, etc."
node.parent.parent.description #> "Collections.  Series.  Collected works"

node.description.path #> [
#> "AC",
#> "Collections.  Series.  Collected works",
#> "Collections of monographs, essays, etc.",  
#> "Pamphlet Collections"  
#> ]

Development

After checking out the repo, run bin/setup to install dependencies. Then, run rake spec to run the tests. You can also run bin/console for an interactive prompt that will allow you to experiment.

To install this gem onto your local machine, run bundle exec rake install. To release a new version, update the version number in version.rb, and then run bundle exec rake release, which will create a git tag for the version, push git commits and tags, and push the .gem file to rubygems.org.

Contributing

Bug reports and pull requests are welcome on GitHub at https://github.com/[USERNAME]/lc_classification.

License

The gem is available as open source under the terms of the MIT License.