ruby-avm-library/lib/avm/image.rb

174 lines
4.0 KiB
Ruby

require 'avm/creator'
require 'avm/xmp'
require 'avm/image_type'
require 'avm/image_quality'
require 'avm/observation'
module AVM
class Image
DUBLIN_CORE_FIELDS = [ :title, :description ]
AVM_SINGLE_FIELDS = [
'Distance.Notes',
'Spectral.Notes',
'ReferenceURL',
'Credit',
'Date',
'ID',
'Type',
'Image.ProductQuality'
]
AVM_SINGLE_METHODS = [
:distance_notes,
:spectral_notes,
:reference_url,
:credit,
:date,
:id,
:type,
:quality
]
AVM_SINGLE_MESSAGES = [
:distance_notes,
:spectral_notes,
:reference_url,
:credit,
:string_date,
:id,
:image_type,
:image_quality
]
AVM_SINGLES = AVM_SINGLE_FIELDS.zip(AVM_SINGLE_METHODS)
attr_reader :creator, :observations
def initialize(options = {})
@creator = AVM::Creator.new(self)
@options = options
@observations = []
end
def create_observation(options)
observation = Observation.new(self, options)
@observations << observation
observation
end
def to_xml
document = AVM::XMP.new
creator.add_to_document(document)
Observation.add_to_document(document, observations)
document.get_refs do |refs|
DUBLIN_CORE_FIELDS.each do |field|
refs[:dublin_core].add_child(%{<dc:#{field}>#{alt_li_tag(send(field))}</dc:#{field}>})
end
refs[:photoshop].add_child(%{<photoshop:Headline>#{headline}</photoshop:Headline>})
AVM_SINGLE_FIELDS.zip(AVM_SINGLE_MESSAGES).each do |tag, message|
value = send(message)
refs[:avm].add_child(%{<avm:#{tag}>#{value.to_s}</avm:#{tag}>}) if value
end
distance_nodes = []
distance_nodes << rdf_li(light_years) if light_years
if redshift
distance_nodes << rdf_li('-') if distance_nodes.empty?
distance_nodes << rdf_li(redshift)
end
if !distance_nodes.empty?
refs[:avm].add_child(%{<avm:Distance><rdf:Seq>#{distance_nodes.join}</rdf:Seq></avm:Distance>})
end
end
document.doc
end
def id
@options[:id]
end
def image_type
(AVM::ImageType.const_get(@options[:type].to_sym).new rescue nil)
end
def image_quality
(AVM::ImageQuality.const_get(@options[:quality].to_sym).new rescue nil)
end
def date
(Time.parse(@options[:date]) rescue nil)
end
def string_date
return nil if !date
date.strftime('%Y-%m-%d')
end
def distance
[ light_years, redshift ]
end
def self.from_xml(string)
document = AVM::XMP.from_string(string)
options = {}
document.get_refs do |refs|
DUBLIN_CORE_FIELDS.each do |field|
if node = refs[:dublin_core].at_xpath(".//dc:#{field}//rdf:li[1]")
options[field] = node.text
end
end
AVM_SINGLES.each do |tag, field|
if node = refs[:avm].at_xpath("./avm:#{tag}")
options[field] = node.text
end
end
if node = refs[:photoshop].at_xpath('./photoshop:Headline')
options[:headline] = node.text
end
if node = refs[:avm].at_xpath('./avm:Distance')
list_values = node.search('.//rdf:li').collect { |li| li.text }
case list_values.length
when 1
options[:light_years] = list_values.first
when 2
options[:light_years] = (list_values.first == '-') ? nil : list_values.first
options[:redshift] = list_values.last
end
end
end
image = new(options)
image.creator.from_xml(self, document)
Observation.from_xml(image, document)
image
end
def method_missing(method)
@options[method]
end
private
def alt_li_tag(text)
%{<rdf:Alt><rdf:li xml:lang="x-default">#{text}</rdf:li></rdf:Alt>}
end
def rdf_li(text)
%{<rdf:li>#{text}</rdf:li>}
end
end
end