This gem is currently used to mask outdated Library of Congress Subject Headings in two different public access catalogs - Princeton University Library Catalog and Princeton University Library Finding Aids.

The code for this gem started in the bibdata codebase, the application that prepares metadata for use by the Catalog, and you can see the gem's earlier history there.

Add this line to your application's Gemfile:

gem 'change_the_subject'

And then execute:

$ bundle install

Or install it yourself as:

$ gem install change_the_subject

The main api of the gem is the ChangeTheSubject.fix method, which takes an array of subject terms, compares them to the configuration (the default is in config/change_the_subject.yml), and replaces the configured terms. You can see how Bibdata uses the gem in its traject_config.rb.

original_subjects = ["Something problematic", "Something not problematic"]
subjects = ChangeTheSubject.fix(subject_terms: original_subjects)
# outputs ["Something not problematic from config", "Something not problematic"]

The ChangeTheSubject.fix method also takes an optional separators argument, which you can see in use in Pulfalight's implementation for eads.

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 the created tag, and push the .gem file to rubygems.org.

The configuration for this gem is managed by the Inclusive and Reparative Metadata Working Group (IRMWG). Send questions or comments about the configuration to harmfullanguage@princeton.libanswers.com.

Bug reports and pull requests are welcome on GitHub at https://github.com/pulibrary/change_the_subject.