[SOLR-10521] sort by string field of the nested child when searching with {!parent}

• Type: New Feature
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Fix Version/s: 6.6, 7.0
• Assignee: Unassigned
• Reporter: Mikhail Khludnev
• Created: 19/Apr/17 12:54
• Updated: 08/Jun/19 15:19
• Resolved: 29/Apr/17 19:18

Description

The idea is to integrate Lucene's ToParentBlockJoinSortField
The approach to hookup it is a little bit tricky:
sort={!childfield bjq=$q field=COLOR_s}desc sort=\childfield(COLOR_s,$q) desc
the question no.1 wdyt about the syntax?
internally it creates a function query with valueSource which produces ToParentBlockJoinSortField

The main challenge is picking Solr field type from ToParentBlockJoinSortField, because as-is it's broken on mergeIds - ByteRefs need to be properly marshaled and unmarshalled by a field type from the child scope.

Issue Links

• is related to: SOLR-10701 sort=parentfield(name,{!child}) asc
• relates to: SOLR-12871 sort=childfield(currency_field) desc fails with exception about REWRITABLE field type
• relates to: SOLR-10668 NPE on sort=childfield(field) desc
• relates to: LUCENE-7798 add equals/hashCode to ToParentBlockJoinSortField