Do PUT requests with the exact modified date (precise to a thousandth of a second)

[jcoyne]

On edge fcrepo4, we get a 409 Conflict error when we attempt to do an update:

Could not remove triple containing predicate http://fedora.info/definitions/v4/repository#lastModified to node /test/9f/30/63/86/9f306386-f98f-4fc0-af2f-8a85cb2257ad

I believe this is because we are sending a lastModifed value with whole second precision, but Fedora has the value precise to a thousandth of a second. We are currently getting this value from the header, but we might need to get it from the graph in order to get the correct precision.

[cbeer]

s/precise to a thousandth of a second/what Fedora gave you in the graph/. Precision isn't really the issue.

[jcoyne]

This will be a challenge. Ruby can dump a date time to any level of precision you want, but you have to specify what that level will be. It looks like RDF.rb is just using DateTime#xmlschema(0) (the default). We'd have to use DateTime#xmlschema(3) in order to get it to match Fedora 4, and as @cbeer says, we shouldn't do to the thousandth, but to whatever precision was given as the input. cc: @gkellogg @no-reply

g = RDF::Graph.new
=> #<RDF::Graph:0x3fefd5e9e2d8(default)>
g.insert([RDF::URI.new('http://example.com/foo'), RDF::DC.available, DateTime.parse("2014-10-22T22:58:00.804Z")])
=> #<RDF::Graph:0x3fefd5e9e2d8(default)>
puts g.dump(:ttl)

<http://example.com/foo> <http://purl.org/dc/terms/available> "2014-10-22T22:58:00Z"^^<http://www.w3.org/2001/XMLSchema#dateTime> .
=> nil

[gkellogg]

RDF::Literal::DateTime actually uses #strftime with a FORMAT constant; you could monkey-patch that. Note that it only formats the literal if it is provided as a native datatype, or it is canonicalized.

FORMAT   = '%Y-%m-%dT%H:%M:%SZ'.freeze

[jcoyne]

I monkey patched RDF::Literal::DateTime in f261ba5