# HydraPbcore

[![Build Status](https://travis-ci.org/curationexperts/hydra-pbcore.png)](https://travis-ci.org/curationexperts/hydra-pbcore)

A Hydra gem that offers PBCore datastream definitions using OM, as well as some other convenience
methods such as inserting xml templates into existing documents and reordering your PBCore xml 
elements so that you can export complete, valid PBCore documents.

## Installation

Add this line to your application's Gemfile:

    gem 'hydra-pbcore'

And then execute:

    $ bundle

Or install it yourself as:

    $ gem install hydra-pbcore

## Usage

Use this with your hydra head to define a datastream in Fedora that will contain Pbcore xml.  Ex:

    MyModel < ActiveFedora::Base

      has_metadata :name => "descMetadata", :type => HydraPbcore::Datastream::Document

    end

Your descMetadata datastream will now have all the pbcore terms defined in HydraPbcore::Datastream::Document.
There are also two additional datastream definitions:

* HydraPbcore::Datastream::DigitalDocument
* HydraPbcore::Datastream::Instantiation

DigitalDocument datastreams have the exact same terms as Document, except that there is no default physical 
pbcoreInstantiation.  The Document datastreams comes with a single instantiation that represents a tape
or other physical entity.  DigitalDocument datastreams assume born-digital content and must have added
instantiations.  These instantiations are defined in the Instantiation datastream.

### Additional Methods

HydraPbcore comes with a couple of additional features such as ordering your xml nodes so that your xml will 
validate against the PBCore XML v.2 schema.  Additionally, there are several template methods that can be used
to insert additional terms into your xml documents, such as contributors, publishers, as well as next and previous
fields that specify which files come before and after one another in a multi-part born-digital video.

### Dates

Date fields in solr have to be in ISO8601 format, as opposed to text fields which may contain dates, but are treated differently.
The difference is with the former, solr is treating the value of the field as an actual date, and as such, it can do time-based
querying.  The latter, is just a string and solr would search it accordingly.  Currently, two types of date fields are provided:
"_dt" for single-valued date fields, and "_dts" for multi-valued date fields.  Solr cannot sort on multi-valued date fields;
otherwise, the two functionally identical.  By indexing your date fields as:

    :index_as => [:displayable, :converted_date]
    :index_as => [:displayable, :converted_multi_date]

the content of your date fields will be converted to ISO8601 dates, and the original content will be preserved for display.
So you could enter a date such as "2001" or "2004-10", and each will be stored for display as such, but will also be 
indexed as a date in Solr with the value "2001-01-01T00:00:00Z" and "2004-10-01T00:00:00Z"

Note: these functions will likely change with the upgrade to Solrizer 3.0.

## Testing

To run all the rspec tests, use:

    rspec spec

Sample xml documents are copied to tmp so you can see what the xml looks like that hydra-pbcore is generating.
These xml samples are compared to examples in spec/fixtures.

## Contributing

1. Fork it
2. Create your feature branch (`git checkout -b my-new-feature`)
3. Commit your changes (`git commit -am 'Added some feature'`)
4. Push to the branch (`git push origin my-new-feature`)
5. Create new Pull Request