Class: AVM::XMP

Inherits:
Object
  • Object
show all
Defined in:
lib/avm/xmp.rb

Overview

An XMP document wrapper, providing namespace handling and document reference assistance.

Constant Summary collapse

PREFIXES = 
{
  'dc' => 'Dublin Core',
  'Iptc4xmpCore' => 'IPTC',
  'photoshop' => 'Photoshop',
  'avm' => 'AVM'
}
REQUIRED_NAMESPACES = 
{
  :x => "adobe:ns:meta/",
  :rdf => "http://www.w3.org/1999/02/22-rdf-syntax-ns#",
  :dc => "http://purl.org/dc/elements/1.1/",
  :photoshop => "http://ns.adobe.com/photoshop/1.0/",
  :avm => "http://www.communicatingastronomy.org/avm/1.0/",
  :Iptc4xmpCore => "http://iptc.org/std/Iptc4xmpCore/1.0/xmlns/"
}

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(doc = nil) ⇒ XMP

Returns a new instance of XMP.

Raises:

  • (StandardError) 


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# File 'lib/avm/xmp.rb', line 25

def initialize(doc = nil)
  @doc = doc || empty_xml_doc

  raise StandardError.new('not a Nokogiri node') if !@doc.kind_of?(::Nokogiri::XML::Node)

  ensure_namespaces!
  ensure_descriptions_findable!
end

Instance Attribute Details

#doc ⇒ Object (readonly)

Returns the value of attribute doc.



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# File 'lib/avm/xmp.rb', line 23

def doc
  @doc
end

Class Method Details

.from_string(string) ⇒ Object 



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# File 'lib/avm/xmp.rb', line 38

def self.from_string(string)
  new(Nokogiri::XML(string))
end

Instance Method Details

#at_xpath(path, node = doc) ⇒ Object 



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# File 'lib/avm/xmp.rb', line 56

def at_xpath(path, node = doc)
  node.at_xpath(*ensure_xpath(path))
end

#ensure_xmlns(string) ⇒ Object Also known as: % 



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# File 'lib/avm/xmp.rb', line 42

def ensure_xmlns(string)
  string.gsub(%r{([</@])(\w+):}) { |all, matches| $1 + (prefix_map[$2] || $2) + ':' }
end

#ensure_xpath(path) ⇒ Object 



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# File 'lib/avm/xmp.rb', line 48

def ensure_xpath(path)
  [ ensure_xmlns(path), namespaces ]
end

#get_refs {|Hash[[ :dublin_core, :iptc, :photoshop, :avm ]| ... } ⇒ Object

Yields:

  • (Hash[[ :dublin_core, :iptc, :photoshop, :avm ]) 


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# File 'lib/avm/xmp.rb', line 34

def get_refs
  yield Hash[[ :dublin_core, :iptc, :photoshop, :avm ].collect { |key| [ key, send(key) ] }]
end

#namespaces ⇒ Object 



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# File 'lib/avm/xmp.rb', line 60

def namespaces
  @namespaces ||= doc.document.collect_namespaces
end

#search(path, node = doc) ⇒ Object 



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# File 'lib/avm/xmp.rb', line 52

def search(path, node = doc)
  node.search(*ensure_xpath(path))
end