Class: EasyTag::TaggerFactory

Inherits:
Object
  • Object
show all
Defined in:
lib/easytag/taggers/factory.rb

Class Method Summary collapse

Class Method Details

.open(file, &block) ⇒ Object 



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# File 'lib/easytag/taggers/factory.rb', line 3

def self.open(file, &block)
  tagger_klass = tagger_class(file)

  if block_given?
    tagger = tagger_klass.new(file)
    begin
      block.call(tagger)
    ensure
      tagger.close
    end
  else
    tagger_klass.new(file)
  end
end

.tagger_class(file) ⇒ Object 



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# File 'lib/easytag/taggers/factory.rb', line 18

def self.tagger_class(file)
  tagger_klass = tagger_for_filename(file)
  if tagger_klass.nil?
    data = nil
    File.open(file, 'rb') { |fp| data = fp.read(16) }
    tagger_klass = tagger_for_signature(data.bytes)
  end

  raise 'Could not determine file type' if tagger_klass.nil?
  tagger_klass
end

.tagger_for_filename(fname) ⇒ Object 



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# File 'lib/easytag/taggers/factory.rb', line 30

def self.tagger_for_filename(fname)
  case fname.split('.')[-1].downcase.to_sym
  when :mp3; MP3Tagger
  when :mp4, :m4a; MP4Tagger
  when :flac; FLACTagger
  when :ogg; OggTagger
  else; nil
  end
end

.tagger_for_signature(bytes) ⇒ Object 



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# File 'lib/easytag/taggers/factory.rb', line 40

def self.tagger_for_signature(bytes)
  case
  when bytes[0...11] == [0, 0, 0, 32, 102, 116, 121, 112, 77, 52, 65] # ...ftypM4A
    MP4Tagger
  when bytes[0...11] == [0, 0, 0, 24, 102, 116, 121, 112, 109, 112, 52] # ...ftypmp4
    MP4Tagger
  when bytes[0...4] == [102, 76, 97, 67] # fLaC
    FLACTagger
  when bytes[0...4] == [79, 103, 103, 83] # OggS
    OggTagger
  when bytes[0...3] == [73, 68, 51] # ID3
    MP3Tagger
  when bytes[0...2] == [255, 251] # FF FB
    MP3Tagger
  else
    nil
  end
end