Lesson: Reading Hydra rightsMetadata XML

This Tutorial is known to work with hydra-head version 6.0.0..
Please update this wiki to reflect any other versions that have been tested.

Steps

Given a book whose permissions look like this:

puts book.permissions
{:type=>"group", :access=>"discover", :name=>"group2"}
{:type=>"group", :access=>"read", :name=>"group3"}
{:type=>"group", :access=>"read", :name=>"group9"}
{:type=>"group", :access=>"read", :name=>"group8"}
{:type=>"user", :access=>"read", :name=>"user3"}
{:type=>"user", :access=>"edit", :name=>"bob1"}
{:type=>"user", :access=>"edit", :name=>"sally2"}

The permissions will be written into the rightsMetadata datstream like so

puts book.rightsMetadata.to_xml
<rightsMetadata xmlns="http://hydra-collab.stanford.edu/schemas/rightsMetadata/v1" version="0.1">
  <copyright>
    <human type="title"/>
    <human type="description"/>
    <machine type="uri"/>
  </copyright>
  <access type="discover">
    <human/>
    <machine>
      <group>group2</group>
    </machine>
  </access>
  <access type="read">
    <human/>
    <machine>
      <group>group3</group>
      <group>group9</group>
      <group>group8</group>
      <person>user3</person>
    </machine>
  </access>
  <access type="edit">
    <human/>
    <machine>
      <person>bob1</person>
      <person>sally2</person>
    </machine>
  </access>
  <embargo>
    <human/>
    <machine/>
  </embargo>
</rightsMetadata>

If we remove the nodes that aren't relevant to this lesson, the XML looks like this:

<rightsMetadata xmlns="http://hydra-collab.stanford.edu/schemas/rightsMetadata/v1" version="0.1">
  <access type="discover">
    <machine>
      <group>group2</group>
    </machine>
  </access>
  <access type="read">
    <machine>
      <group>group3</group>
      <group>group9</group>
      <group>group8</group>
      <person>user3</person>
    </machine>
  </access>
  <access type="edit">
    <machine>
      <person>bob1</person>
      <person>sally2</person>
    </machine>
  </access>
</rightsMetadata>

As you can see, group ids are put into <group> nodes and user ids are put into <person> nodes. The type of access being granted is decided by the @type attribute on the <access> nodes.

The intermediary <machine> node is meant to allow you to insert human-readable information into the 'access/human' node while inserting the machine-readable assertions into 'access/machine' node.

Next Step

Go on to Lesson: Indexing Hydra Rights Metadata into Solr or return to the Access Controls with Hydra tutorial.