Background information ---------------------- Dewey Decimal Classification (DDC) [1] numbers can be stored in MARC21 authority records as follows ('R' and 'NR' denoting 'Repeatable' and 'Non-Repeatable' fields/subfields, respectively): 082 - Dewey Decimal Call Number (R) 082$a - Classification number (NR) 083 - Dewey Decimal Classification Number (R) 083$a - Classification number element-single number or beginning number of span (NR) 083$b - Classification number element-ending number of span (NR) Since 2024, both MARC21 and UNIMARC standards have been updated to enable storing information in the form of Real World Object URIs, corresponding to either a single DDC number or a DDC number range. Such URIs are stored in MARC21 subfield 082$1 / 083$1. Here's an example provided by LoC: 082 0 4 $a 205 $2 23/eng/20230428 $1 https://id.oclc.org/worldcat/ddc/E3wr6cb9BxbG4wDPXgHCPXYfYw For more information, please refer to the LoC website [2,3]: The OCLC Dewey Linked Data API ------------------------------ OCLC recently [4] started offering a Linked Data (LD) [5] API [6] that allows looking up DDC numbers to obtain unique URIs/URLs and Descriptions for a particular DDC number (or range). In addition to API searches, a smaller subset of the LD can also be browsed online in a hierarchical manner [7]. Reasoning behind this Bug report -------------------------------- We believe that Koha users who include DDC numbers in their authority cataloguing would benefit from an integration with the OCLC Dewey LD API that would allow them to easily lookup DDCs in exchange for LD URIs/URLs and Descriptions. To this end, we propose the addition of a new Authority Framework plugin for MARC21 that will offer this functionality. This plugin builds on the groundwork laid by Bug 40308, in order to offer 1-click DDC lookups from within the Authorities cataloguing editor. References: [1] https://www.oclc.org/content/dam/oclc/dewey/versions/print/intro.pdf [2] https://www.loc.gov/marc/authority/ad082.html [3] https://www.loc.gov/marc/authority/ad083.html [4] https://www.oclc.org/en/news/releases/2024/20240815-uniform-resource-identifiers-for-ddc-numbers.html [5] https://www.oclc.org/en/linked-data.html [6] https://developer.api.oclc.org/dewey-ld [7] https://entities.oclc.org/worldcat/ddc/
Created attachment 183814 [details] [review] Bug 40309: add new Authority Framework plugin for MARC21 082$a This Authority Framework plugin should be attached to MARC21 authority subfield 082$a, which will then allow the cataloguer to lookup a single DDC in exchange for a Dewey Linked Data URL that will be copied to subfield 082$1. Test plan: 1) Go to Administration > Authority types, and for each authtype associate subfield 082$a with the marc21_field_082a_authorities.pl plugin. 2) Create a new authority, or edit an existing one. Click on the 'Tag editor' button on the far right of the 082$a subfield. Experiment with the behaviour of the plugin when no DDC has been filled in, or when an erroneous DDC has been filled in. Monitor your browser's JavaScript console for warnings/errors (there shouldn't be any!). 3) Experiment with changing the values of the related System Preferences (found under the 'OCLC Dewey Linked Data API' heading) and seeing how it affects the behaviour of the plugin.