Free text search: handling chromosome/start

[bbimber]

Users will want to search on start position, but this is always linked to a contig/chromosome. These are actually two fields, but to a user it would be helpful if it acted like one. I propose we:

• On the client, expose a filter type for 'position'. They enter values like: "1:1000122". The allowed operators would be numeric (i.e. equals, GT, LT, GTE, LTE).
• The react field should validate the user's input
• The react field should probably drop whitespace and commas automatically. Or maybe disallow typing them to begin with?
• The client-side code should translate the user input of "position greater than 1:1000222", into a lucene query that is "contig equals 1 AND start greater than 1000222". This should just happen without the user needing to see or know it's occurring.
• For the task for serializing/deserializing filters on the URL, we can probably serialize the user string.

Side note: the DISCVR-seq tool indexes a field called 'genomicPosition'. This in a running total of the position within the genome. Therefore the genomicPosition of chromosome 2 position 100 is the length of chromosome 1 plus 100. The idea is to give us a simple integer for positional sorting. I think we want lucene to return 100% of queries sorted on genomicPosition. And I think we never want to show this field to the user.