Class: Rubydora::Datastream

Inherits:
Object
  • Object
show all
Extended by:
ActiveModel::Callbacks
Includes:
ActiveModel::Dirty, ExtensionParameters
Defined in:
lib/rubydora/datastream.rb

Overview

This class represents a Fedora datastream object and provides helper methods for creating and manipulating them.

Constant Summary collapse

DS_ATTRIBUTES =

mapping datastream attributes (and api parameters) to datastream profile names

{:controlGroup => :dsControlGroup, :dsLocation => :dsLocation, :altIDs => nil, :dsLabel => :dsLabel, :versionable => :dsVersionable, :dsState => :dsState, :formatURI => :dsFormatURI, :checksumType => :dsChecksumType, :checksum => :dsChecksum, :mimeType => :dsMIME, :logMessage => nil, :ignoreContent => nil, :lastModifiedDate => nil, :content => nil}

Instance Attribute Summary collapse

Instance Method Summary collapse

Methods included from ExtensionParameters

#apply_extensions, included

Constructor Details

#initialize(digital_object, dsid, options = {}) ⇒ Datastream

Initialize a Rubydora::Datastream object, which may or may not already exist in the datastore.

Provides ‘after_initialize` callback for extensions

Parameters:

  • (Rubydora::DigitalObject)
  • Datastream (String) —

    ID

  • default (Hash) —

    attribute values (used esp. for creating new datastreams)



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# File 'lib/rubydora/datastream.rb', line 43

def initialize digital_object, dsid, options = {}
  _run_initialize_callbacks do
  @digital_object = digital_object
  @dsid = dsid
  options.each do |key, value|
    self.send(:"#{key}=", value)
  end
  end
end

Instance Attribute Details

#digital_object ⇒ Object (readonly)

Returns the value of attribute digital_object.



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# File 'lib/rubydora/datastream.rb', line 13

def digital_object
  @digital_object
end

#dsid ⇒ Object (readonly)

Returns the value of attribute dsid.



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# File 'lib/rubydora/datastream.rb', line 13

def dsid
  @dsid
end

Instance Method Details

#content ⇒ String Also known as: read

Retrieve the content of the datastream (and cache it)

Returns:

  • (String) 


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# File 'lib/rubydora/datastream.rb', line 66

def content
  begin
    @content ||= repository.datastream_dissemination :pid => pid, :dsid => dsid
  rescue RestClient::ResourceNotFound
  end

  content = @content.read and @content.rewind if @content.kind_of? IO
  content ||= @content
end

#content=(new_content) ⇒ String or IO

Set the content of the datastream

Parameters:

  • (String or IO)

Returns:

  • (String or IO) 


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# File 'lib/rubydora/datastream.rb', line 86

def content= new_content
   content_will_change!
   @content = new_content
end

#create ⇒ Rubydora::Datastream

Add datastream to Fedora

Returns:



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# File 'lib/rubydora/datastream.rb', line 115

def create
  repository.add_datastream to_api_params.merge({ :pid => pid, :dsid => dsid })
  reset_profile_attributes
  Datastream.new(digital_object, dsid)
end

#delete ⇒ Rubydora::Datastream

Purge the datastream from Fedora

Returns:



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# File 'lib/rubydora/datastream.rb', line 132

def delete
  repository.purge_datastream(:pid => pid, :dsid => dsid) unless self.new?
  digital_object.datastreams.delete(dsid)
  reset_profile_attributes
  self
end

#new? ⇒ Boolean

Does this datastream already exist?

Returns:

  • (Boolean) 


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# File 'lib/rubydora/datastream.rb', line 60

def new?
  profile.empty?
end

#pid ⇒ Object

Helper method to get digital object pid



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# File 'lib/rubydora/datastream.rb', line 54

def pid
  digital_object.pid
end

#profile ⇒ Hash

Retrieve the datastream profile as a hash (and cache it)

Returns:

  • (Hash) —

    see Fedora #getDatastream documentation for keys



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# File 'lib/rubydora/datastream.rb', line 93

def profile
  @profile ||= begin
    profile_xml = repository.datastream(:pid => pid, :dsid => dsid)
    profile_xml.gsub! '<datastreamProfile', '<datastreamProfile xmlns="http://www.fedora.info/definitions/1/0/management/"' unless profile_xml =~ /xmlns=/
    doc = Nokogiri::XML(profile_xml)
    h = doc.xpath('/management:datastreamProfile/*', {'management' => "http://www.fedora.info/definitions/1/0/management/"} ).inject({}) do |sum, node|
                 sum[node.name] ||= []
                 sum[node.name] << node.text
                 sum
               end
    h.select { |key, value| value.length == 1 }.each do |key, value|
      h[key] = value.first
    end

    h
  rescue
    {}
  end
end

#save ⇒ Rubydora::Datastream

Modify or save the datastream

Returns:



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# File 'lib/rubydora/datastream.rb', line 123

def save
  return create if new?
  repository.modify_datastream to_api_params.merge({ :pid => pid, :dsid => dsid })
  reset_profile_attributes
  Datastream.new(digital_object, dsid)
end

#url ⇒ String

Get the URL for the datastream content

Returns:

  • (String) 


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# File 'lib/rubydora/datastream.rb', line 79

def url
  repository.datastream_url(pid, dsid) + "/content"
end