Library of Congress Subject Headings
[Valid for v1.3]
Unlike other CollectiveAccess vocabularies that are treated as Lists (and controlled through the Lists and Vocabulary Manager), Library of Congress Subject Headings are handled through a lookup and are therefore accessed through a metadata element. To create the LCSH attribute follow these instructions.
Setting up a LCSH field in an installation profile
The steps for creating a LCSH lookup field in an installation profile are almost exactly the same as creating an element of any other type. The element set must be declared, in this case with 'LCSH', the settings must be established and the type restrictions must be configured.
<metadataElement code="lcsh_terms" datatype="LCSH"> <labels> <label locale="en_US"> <name>Library of Congress Subject Headings</name> <description>Library of Congress Subject headings describing this object.</description> </label> </labels> <settings> <setting name="fieldWidth">80</setting> <setting name="fieldHeight">1</setting> <setting name="vocabulary">cs:http://id.loc.gov/authorities/subjects</setting> </settings> <typeRestrictions> <restriction code="ca_objects"> <table>ca_objects</table> <settings> <setting name="minAttributesPerRow">0</setting> <setting name="maxAttributesPerRow">100</setting> <setting name="minimumAttributeBundlesToDisplay">1</setting> </settings> </restriction> </typeRestrictions> </metadataElement>
In the example above, a setting has been used to limit the vocabulary to ONLY Subject Headings, thereby omitting Name Authority File, Subject Headings for Children, Thesaurus of Graphic Materials and all of the other LC vocabularies. A full list of settings, including codes used to restrict lookups, can be found here.
Setting up a LCSH field through the user interface
Navigate to Manage > Administration > Metadata elements. Click the "+New" button on the upper right hand corner of the screen.
Set up your field as you would any other type of element, but be sure to select LCSH from the Datatype drop down list.
To select the vocabulary type restriction demonstrated in the code example above, use the vocabularies drop down at the bottom of the element screen.
Make sure to complete the type restrictions and then you're ready to place the element on the user interface screen of your choosing.