Class: IIIF::V3::Presentation::Canvas

Inherits:
AbstractResource show all
Defined in:
lib/iiif/v3/presentation/canvas.rb

Constant Summary collapse

TYPE = 
'Canvas'.freeze

Constants inherited from AbstractResource

AbstractResource::CONTENT_RESOURCE_PROPERTIES, AbstractResource::PAGING_PROPERTIES

Constants included from HashBehaviours

HashBehaviours::SIMPLE_SELF_RETURNERS

Instance Method Summary collapse

Methods inherited from AbstractResource

#any_type_keys, from_ordered_hash, #hash_only_keys, #legal_viewing_direction_values, #numeric_only_keys, parse, #string_only_keys, #to_json, #to_ordered_hash, #uri_only_keys

Methods included from HashBehaviours

#clear, #merge, #merge!, #reject!, #select, #select!

Constructor Details

#initialize(hsh = {}) ⇒ Canvas 



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# File 'lib/iiif/v3/presentation/canvas.rb', line 28

def initialize(hsh={})
  hsh['type'] = TYPE unless hsh.has_key? 'type'
  super(hsh)
end

Instance Method Details

#array_only_keys ⇒ Object 



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# File 'lib/iiif/v3/presentation/canvas.rb', line 20

def array_only_keys
  super + %w{ content }
end

#int_only_keys ⇒ Object 



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# File 'lib/iiif/v3/presentation/canvas.rb', line 16

def int_only_keys
  super + %w{ depth }
end

#legal_viewing_hint_values ⇒ Object 



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# File 'lib/iiif/v3/presentation/canvas.rb', line 24

def legal_viewing_hint_values
  super + %w{ paged continuous non-paged facing-pages auto-advance }
end

#prohibited_keys ⇒ Object 



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# File 'lib/iiif/v3/presentation/canvas.rb', line 12

def prohibited_keys
  super + PAGING_PROPERTIES + %w{ viewing_direction format nav_date start_canvas content_annotations }
end

#required_keys ⇒ Object 



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# File 'lib/iiif/v3/presentation/canvas.rb', line 8

def required_keys
  super + %w{ id label }
end

#validate ⇒ Object 



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# File 'lib/iiif/v3/presentation/canvas.rb', line 33

def validate
  super

  id_uri = URI.parse(self['id'])
  unless self['id'] =~ /^https?:/ && id_uri.fragment.nil?
    err_msg = "id must be an http(s) URI without a fragment for #{self.class}"
    raise IIIF::V3::Presentation::IllegalValueError, err_msg
  end

  content = self['content']
  if content && content.any?
    unless content.all? { |entry| entry.instance_of?(IIIF::V3::Presentation::AnnotationPage) }
      err_msg = 'All entries in the content list must be a IIIF::V3::Presentation::AnnotationPage'
      raise IIIF::V3::Presentation::IllegalValueError, err_msg
    end
    content.each do |anno_page|
      annos = anno_page['items']
      if annos && annos.any?
        unless annos.all? { |anno| anno.target == self.id }
          err_msg = 'URI of the canvas must be repeated in the target field of included Annotations'
          raise IIIF::V3::Presentation::IllegalValueError, err_msg
        end
      end
    end
  end

  # "A canvas MUST have exactly one width and one height, or exactly one duration.
  # It may have width, height and duration.""
  height = self['height']
  width = self['width']
  if (!!height ^ !!width) # this is an exclusive or: forces height and width to boolean
    extent_err_msg = "#{self.class} requires both height and width or neither"
    raise IIIF::V3::Presentation::IllegalValueError, extent_err_msg
  end
  # NOTE:  relaxing requirement for (exactly one width and one height, and/or exactly one duration)
  #  as Stanford has objects (such as txt files) for which this makes no sense
  #  (see sul-dlss/purl/issues/169)
  # duration = self['duration']
  # unless (height && width) || duration
  #   extent_err_msg = "#{self.class} must have (a height and a width) and/or a duration"
  #   raise IIIF::V3::Presentation::IllegalValueError, extent_err_msg
  # end

  # TODO: Content must not be associated with space or time outside of the Canvas’s dimensions,
  # such as at coordinates below 0,0, greater than the height or width, before 0 seconds, or after the duration.
end