PURL

PURL service is a URL resolver that translates a reference to a digital object (in the form of a druid), into a full content representation of that object as available in public access environment

Requirements

1. Ruby (3.2 or greater)
2. bundler gem

Installation

Clone the repository

$ git clone git@github.com:sul-dlss/purl.git

Move into the app and install dependencies

$ cd purl
$ bundle install

Start the development server

$ bin/dev

Configuring

Configuration is handled through the RailsConfig settings.yml files.

Development

The defaults in config/settings.yml should work on a locally run installation.

By default, local development will use production XML from PURL, so that you can hit any valid object when testing locally. If you want to use local XML for testing, which can be useful if you want to alter data and see the results, do this:

1. Create a local "document_cache" folder in the root of the PURL rails app on your laptop.
2. Create druid tree folders (e.g. document_cache/xk/755/gc/8675, just like they would be on stacks) and put mods and public XML files there. You can get examples from the spec/fixtures/document_cache or production PURL. Note that the document_cache folder is already in .gitignore so any content copied there will not be added to git. An easy solution would be to run ln -s spec/fixtures/document_cache ..
3. Create a config/settings.local.yml file (if you don't have one already) and add the following:

# Comment out for lookup to production PURL
purl_resource:
  public_xml: "%{root_path}/%{druid_tree}/public"
  cocina: "%{root_path}/%{druid_tree}/cocina.json"
  meta: "%{root_path}/%{druid_tree}/meta.json"
  versioned:
    public_xml: "%{root_path}/%{druid_tree}/%{druid}/versions/public.%{version_id}.xml"
    cocina: "%{root_path}/%{druid_tree}/%{druid}/versions/cocina.%{version_id}.json"
    meta: "%{root_path}/%{druid_tree}/%{druid}/versions/meta.json"

stacks:
  version_manifest_path: "%{root_path}/%{druid_tree}/%{druid}/versions/versions.json"

If you leave this config uncommented, the local app will find content in the local document_cache. If you comment it out, it will revert to the default behavior (look up content on PURL).

Debugging

When the Rails server is run using bin/dev, you can start up a debugger session in a separate terminal via:

rdbg -A

To drop into the debugger, add debugger statements where needed in the code and have fun navigating the stack in your debugger session terminal.

Testing

The test suite (with RuboCop style enforcement) will be run with the default rake task (also run on travis)

$ rake

The specs can be run without RuboCop style enforcement

$ rake spec

The RuboCop style enforcement can be run without running the tests

$ rake rubocop

Deploying

Deployment is handled automatically via Jenkins when a release is published to GitHub.

Data

Purl data is stored in a pair-tree structure starting at Settings.document_cache_root. In each pair-tree is a file called cocina.json which is the public representation of the current version of the object. There is also a meta.json file that holds information about where this object is released to. The meta.json is not versionable data. Additionally there is an XML file called public which has a representation of the object that was derived from cocina.json.

Search engine indexing

Only items with "PURL sitemap" release tag (in meta.json) are included in the sitemap and all other items have a "noindex" meta tag.

Structured metadata in the form of schema.org markup is generated to enhance discoverability of datasets and videos. More info about schema.org markup.