Extend the OPDS feed model so clients can page through large catalogs and
discover how to search them.
Feed changes:
- Add the OpenSearch namespace (xmlns:opensearch) to all feeds.
- Add optional TotalResults/ItemsPerPage/StartIndex fields, serialized as
<opensearch:totalResults>, <opensearch:itemsPerPage> and
<opensearch:startIndex>, plus a SetPagination helper.
- Add OpenSearchDescription/OpenSearchUrl types and a NewSearchDescription
constructor with GenerateXML/GenerateXMLString. This produces the
OpenSearch description document (application/opensearchdescription+xml)
that OPDS clients like KOReader fetch to learn the {searchTerms} search
URL template.
These are building blocks; the handlers are wired up in a follow-up commit.
Tests cover SetPagination, omission when unset, XML emission of the
paging metadata, and OpenSearch description generation/serialization.
john-okeefe
9920fd47b9