Save time zone information for DateTimes. Solr returns DateTimes rather than Strings.

[ojlyytinen]

As it stands, time zone information is not stored in Fedora, instead it's just always set to Z. All time information is effectively shifted by your local time offset if you take time zones into account. This results in unexpected behaviour where timestamps for example end up in the future if your local time zone offset is positive.

class Foo < ActiveFedora::Base
  property :date, predicate: ::RDF::DC.date do |index|
    index.type :date
  end
end

foo = Foo.create(date: [DateTime.now])
sleep 1
foo.date.first > DateTime.now # => true assuming your time offset is positive

There seems to be a bug in RDF::Literal::DateTime#to_s which prints out time zone as Z if you initialise the object with a DateTime rather than a String, so this should be fixed there. But a similar bug is present also in the monkey patch applied in lib/active_fedora.rb which is fixed in this PR.

The PR also makes Solr-loaded documents return DateTime objects rather than Strings when indexing type has been set to date. What used to happen is that the same field which returned a DateTime object when loaded from Fedora would return a String when loaded from Solr.

[jcoyne]

Where is the "load" happening in this scenario?

[ojlyytinen]

It seems to reset attributes after save (or create). At least the time zone gets reset with create alone and that test fails. I could add a .reload in there though just in case.

[jcoyne]

Please rebase your changes and run rubocop. I suspect it will tell you to remove a bunch of returns at the end of methods.

[ojlyytinen]

We can't really use the field name suffixes to determine the type of the field since loading only uses the object_profile which doesn't have those suffixes. As far as I can tell, the only information we have about the field is what's in ActiveFedora::Attributes::NodeConfig and the attribute value itself. I've now changed it to parse the value as a DateTime if the node config has type == :date or class_name == DateTime. When defining properties these are set with index.type :date and class_name: 'DateTime', respectively. Either will work.

Rubocop didn't mind the returns at the end of methods but I removed them anyway. And it didn't like the complexity of adapt_attribute_value so I restructured it a little bit.