Class: Cul::Image::Properties::Base

Inherits:
Object
  • Object
show all
Defined in:
lib/cul_image_props/image/properties/types.rb

Direct Known Subclasses

Bmp, Gif, Jpeg, Png, Tiff

Constant Summary collapse

BASE_XML = 
Nokogiri::XML.parse(<<-xml
<rdf:Description xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#"
 xmlns:exif="http://www.w3.org/2003/12/exif/ns#"
 xmlns:dcmi="http://purl.org/dc/terms/"></rdf:Description>
xml
)

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(srcfile = nil) ⇒ Base

Returns a new instance of Base.



31
32
33
34
35
 
# File 'lib/cul_image_props/image/properties/types.rb', line 31

def initialize(srcfile=nil)
  @src = srcfile
  @src.rewind
  @ng_xml = BASE_XML.clone
end

Instance Attribute Details

#nodeset ⇒ Object

Returns the value of attribute nodeset.



24
25
26
 
# File 'lib/cul_image_props/image/properties/types.rb', line 24

def nodeset
  @nodeset
end

Instance Method Details

#[](key) ⇒ Object 



49
50
51
52
53
54
55
56
57
58
59
60
61
 
# File 'lib/cul_image_props/image/properties/types.rb', line 49

def [](key)
  result = nil
  nodeset.each { |node|
    if (node.namespace.href + node.name) == key
      if node.attribute('resource').nil?
        result = node.text
      else
        result = node.attribute('resource').value
      end
    end
  }
  result
end

#add_dt_prop(prefix, name, value) ⇒ Object 



62
63
64
65
66
67
 
# File 'lib/cul_image_props/image/properties/types.rb', line 62

def add_dt_prop(prefix, name, value)
  prop = @ng_xml.create_element(name)
  @ng_xml.root.namespace_definitions.each { |ns| prop.namespace = ns if ns.prefix == prefix }
  prop.add_child(@ng_xml.create_text_node(value.to_s))
  @ng_xml.root.add_child( prop )
end

#extent=(value) ⇒ Object 



90
91
92
 
# File 'lib/cul_image_props/image/properties/types.rb', line 90

def extent=(value)
  add_dt_prop("dcmi", "extent", value)
end

#format=(value) ⇒ Object 



94
95
96
 
# File 'lib/cul_image_props/image/properties/types.rb', line 94

def format=(value)
  add_dt_prop("dcmi", "format", value)
end

#hex_inspect(str) ⇒ Object 



98
99
100
101
102
 
# File 'lib/cul_image_props/image/properties/types.rb', line 98

def hex_inspect(str)
  result = []
  (0...str.length).each {|ix| result << str[ix].to_s(16)}
  result.inspect
end

#length=(value) ⇒ Object 



86
87
88
 
# File 'lib/cul_image_props/image/properties/types.rb', line 86

def length=(value)
  add_dt_prop("exif", "imageLength", value)
end

#ord_value(val) ⇒ Object

this is a hack to deal with Ruby 1.9 shenanigans



37
38
39
40
41
42
43
44
45
 
# File 'lib/cul_image_props/image/properties/types.rb', line 37

def ord_value(val)
  if val.is_a? Fixnum
    return val
  elsif val.is_a? String
    return val.unpack('C')[0]
  else
    return val.to_i
  end
end

#sampling_unit=(value) ⇒ Object 



69
70
71
72
 
# File 'lib/cul_image_props/image/properties/types.rb', line 69

def sampling_unit=(value)
  raise "resolutionUnit values must be in the set #{RESOLUTION_VALUES.inspect}" unless RESOLUTION_VALUES.include? value
  add_dt_prop("exif", "resolutionUnit", value)
end

#width=(value) ⇒ Object 



82
83
84
 
# File 'lib/cul_image_props/image/properties/types.rb', line 82

def width=(value)
  add_dt_prop("exif", "imageWidth", value)
end

#x_sampling_freq=(value) ⇒ Object 



74
75
76
 
# File 'lib/cul_image_props/image/properties/types.rb', line 74

def x_sampling_freq=(value)
  add_dt_prop("exif", "xResolution", value)
end

#y_sampling_freq=(value) ⇒ Object 



78
79
80
 
# File 'lib/cul_image_props/image/properties/types.rb', line 78

def y_sampling_freq=(value)
  add_dt_prop("exif", "yResolution", value)
end