classifoclc

Classifoclc

Interface to OCLC's Classify service, "a FRBR-based prototype designed to support the assignment of classification numbers and subject headings for books, DVDs, CDs, and other types of materials." See the OCLC documentation. Classifoclc is aimed mainly at getting works from various other identifiers.

Installation

Add this line to your application's Gemfile:

gem 'classifoclc'

And then execute:

$ bundle

Or install it yourself as:

$ gem install classifoclc

Usage

Look ups

The easiest way to use Classifoclc is to lookup works by several standard identifiers:

• Classifoclc::isbn
• Classifoclc::lccn
• Classifoclc::oclc
• Classifoclc::owi

Each of these returns an Enumerator that can be looped over to get the individual Classifoclc::Work objects. A "work" is an abstraction, and each work has one or more editions. An "edition" is a physical (or digital) item that can be held by a library. From the Classifoclc::Work object you can get several pieces of information, most usefully, perhaps, the number of editions (#edition_count), the number of libraries that hold the work (#holdings) and and that hold the work digitally (#eholdings), and the editions themselves (#editions)

> works = Classifoclc::isbn("0151592659")
> wrk = works.first
> wrk.title
 => "Meridian"
> wrk.owi
 => "201096"
> wrk.format
 => "Book"
> wrk.itemtype
 => "itemtype-book"
> wrk.edition_count
 => 114
> wrk.holdings
 => 3264
> wrk.eholdings
 => 196
> wrk.editions # Returns an Enumerator
> wrk.authors # Returns an Array
> wrk.recommendations # Returns a Recommendations object

A work has an array authors which seems to include all the authors of all the editions of a work, including their VIAF and LC identifiers:

> work = Classifoclc::isbn("0151592659").first
> auth = work.authors.first
> auth.name
 => "Walker, Alice, 1944-"
> auth.viaf
 => "108495772"
> auth.lc
 => "n79109131"

You can also lookup by author(Classifoclc::author), title (Classifoclc::title) and FAST identifier (Classifoclc::fast) but these can return a very large number of results that take a long time and thousands of requests to return.

Finally, you can search by author and title:

> works = Classifoclc::authorAndTitle("Walker, Alice", "Meridian")
> works.count
 => 5
> works.first.owi
 => "201096"
> works.first.edition_count
 => 114	 

Sort order

You can change how the results are sorted by passing an :orderby and/or :order parameter to the lookup. :orderby can take one of the following values:

Contant	Meaning
Classifoclc::OrderBy::EDITIONS	Number of editions the work has (default)
Classifoclc::OrderBy::HOLDINGS	Number of libraries that hold the work
Classifoclc::OrderBy::FIRSTYEAR	Date of first edition
Classifoclc::OrderBy::LASTYEAR	Date of latest edition
Classifoclc::OrderBy::LANGUAGE	Language
Classifoclc::OrderBy::HEADING	FAST subject heading
Classifoclc::OrderBy::WORKS	Number of works with this FAST subject heading
Classifoclc::OrderBy::SUBJTYPE	FAST subject type

:order can be either Classifoclc::Order::ASC (default) or Classifoclc::Order::DESC.

> works = Classifoclc::isbn("0151592659", :orderby => Classifoclc::OrderBy::HOLDINGS, :order => Classifoclc::Order::DESC)

Editions

Use the #editions method to get editions of a work. The method returns an Enumerator

> work = Classifoclc::isbn("0151592659").first
> work.edition_count
 => 114
> work.editions.each do |ed|
 # 114 loops
> end
> ed = work.editions.first
> ed.oclc
 => "2005960"
> ed.title
 => "Meridian"
> ed.format
 => "Book"
> ed.itemtype
 => "itemtype-book"
> ed.holdings
 => 1420
> ed.eholdings
 => 0
> ed.language
 => "eng"
> ed.authors
 => "Walker, Alice, 1944-"
> ed.classifications
 => [{:edition=>"0", :ind1=>"0", :ind2=>"0", :sf2=>"00", :sfa=>"813.54", :tag=>"082"}, {:ind1=>"0", :ind2=>"0", :sfa=>"PS3573.A425", :tag=>"050"}, {:ind1=>"0", :ind2=>"0", :sfa=>"PZ4.W176", :tag=>"050"}]
 

Note that Edition#authors just returns a string, not an Array of Author objects like Work#authors

For the meaning of the classifications, refer to the OCLC documentation.

Recommendations

Each Work has a set of recommended classifications available through the #recommendations method. This returns a Recommendations object

> work = Classifoclc::isbn("0151592659").first
> recs = work.recommendations

The recommendations include an array of FAST subject headings

> recs.fast.first
 => {:heading=>"Southern States", :holdings=>"2945", :ident=>"1244550"}
 

LCC and Dewey Decimal recommendations are each hashes with the possible keys :mostPopular, :mostRecent, and :latestEdition. For each key the value is an array of recommended classifiers:

> recs.lcc[:mostPopular].first
 => {:holdings=>"3221", :nsfa=>"PS3573.A425", :sfa=>"PS3573.A425"}
recs.ddc[:mostPopular].first
 => {:holdings=>"2632", :nsfa=>"813.54", :sfa=>"813.54"}
 

For the meaning of the classifications, refer to the OCLC documentation.

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/seanredmond/classifoclc. This project is intended to be a safe, welcoming space for collaboration, and contributors are expected to adhere to the Contributor Covenant code of conduct.

License

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

Code of Conduct

Everyone interacting in the Classifoclc project’s codebases, issue trackers, chat rooms and mailing lists is expected to follow the code of conduct.