Class: Echonest::Api

Inherits:
Object
  • Object
show all
Defined in:
lib/echonest/api.rb

Defined Under Namespace

Classes: Error

Constant Summary collapse

VERSION = 
'3'
BASE_URL = 
'http://developer.echonest.com/api/'
USER_AGENT = 
'%s/%s' % ['ruby-echonest', ::Echonest::VERSION]

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(api_key) ⇒ Api

Returns a new instance of Api.



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# File 'lib/echonest/api.rb', line 14

def initialize(api_key)
  @api_key = api_key
  @user_agent = HTTPClient.new(:agent_name => USER_AGENT)
end

Instance Attribute Details

#user_agent ⇒ Object (readonly)

Returns the value of attribute user_agent.



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# File 'lib/echonest/api.rb', line 12

def user_agent
  @user_agent
end

Instance Method Details

#build_params(params) ⇒ Object 



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# File 'lib/echonest/api.rb', line 144

def build_params(params)
  params = params.
    merge(:version => VERSION).
    merge(:api_key => @api_key)
end

#get_analysys(method, filename) ⇒ Object 



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# File 'lib/echonest/api.rb', line 150

def get_analysys(method, filename)
  get_trackinfo(method, filename) do |response|
    yield response.xml.find_first('/response/analysis')
  end
end

#get_bars(filename) ⇒ Object 



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# File 'lib/echonest/api.rb', line 19

def get_bars(filename)
  get_analysys(:get_bars, filename) do |analysis|
    analysis.map do |bar|
      Bar.new(bar.content.to_f, bar['confidence'].to_f)
    end
  end
end

#get_beats(filename) ⇒ Object 



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# File 'lib/echonest/api.rb', line 27

def get_beats(filename)
  get_analysys(:get_beats, filename) do |analysis|
    analysis.map do |beat|
      Beat.new(beat.content.to_f, beat['confidence'].to_f)
    end
  end
end

#get_duration(filename) ⇒ Object 



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# File 'lib/echonest/api.rb', line 85

def get_duration(filename)
  get_analysys(:get_duration, filename) do |analysis|
    analysis.first.content.to_f
  end
end

#get_end_of_fade_in(filename) ⇒ Object 



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# File 'lib/echonest/api.rb', line 91

def get_end_of_fade_in(filename)
  get_analysys(:get_end_of_fade_in, filename) do |analysis|
    analysis.first.content.to_f
  end
end

#get_key(filename) ⇒ Object 



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# File 'lib/echonest/api.rb', line 97

def get_key(filename)
  get_analysys(:get_key, filename) do |analysis|
    ValueWithConfidence.new(analysis.first.content.to_i, analysis.first['confidence'].to_f)
  end
end

#get_loudness(filename) ⇒ Object 



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# File 'lib/echonest/api.rb', line 103

def get_loudness(filename)
  get_analysys(:get_loudness, filename) do |analysis|
    analysis.first.content.to_f
  end
end

#get_metadata(filename) ⇒ Object 



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# File 'lib/echonest/api.rb', line 109

def get_metadata(filename)
  get_analysys(:get_metadata, filename) do |analysis|
    analysis.inject({}) do |memo, key|
      memo[key.name] = key.content
      memo
    end
  end
end

#get_mode(filename) ⇒ Object 



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# File 'lib/echonest/api.rb', line 118

def get_mode(filename)
  get_analysys(:get_mode, filename) do |analysis|
    ValueWithConfidence.new(analysis.first.content.to_i, analysis.first['confidence'].to_f)
  end
end

#get_sections(filename) ⇒ Object 



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# File 'lib/echonest/api.rb', line 74

def get_sections(filename)
  get_analysys(:get_sections, filename) do |analysis|
    analysis.map do |section|
      Section.new(
        section['start'].to_f,
        section['duration'].to_f
      )
    end
  end
end

#get_segments(filename) ⇒ Object 



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# File 'lib/echonest/api.rb', line 35

def get_segments(filename)
  get_analysys(:get_segments, filename) do |analysis|
    analysis.map do |segment|
      max_loudness = loudness = nil

      segment.find('loudness/dB').map do |db|
        if db['type'] == 'max'
          max_loudness = Loudness.new(db['time'].to_f, db.content.to_f)
        else
          loudness = Loudness.new(db['time'].to_f, db.content.to_f)
        end
      end

      pitches = segment.find('pitches/pitch').map do |pitch|
        pitch.content.to_f
      end

      timbre = segment.find('timbre/coeff').map do |coeff|
        coeff.content.to_f
      end

      Segment.new(
        segment['start'].to_f,
        segment['duration'].to_f,
        loudness,
        max_loudness,
        pitches,
        timbre
        )
    end
  end
end

#get_start_of_fade_out(filename) ⇒ Object 



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# File 'lib/echonest/api.rb', line 124

def get_start_of_fade_out(filename)
  get_analysys(:get_start_of_fade_out, filename) do |analysis|
    analysis.first.content.to_f
  end
end

#get_tatums(filename) ⇒ Object 



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# File 'lib/echonest/api.rb', line 130

def get_tatums(filename)
  get_analysys(:get_tatums, filename) do |analysis|
    analysis.map do |tatum|
      Tatum.new(tatum.content.to_f, tatum['confidence'].to_f)
    end
  end
end

#get_tempo(filename) ⇒ Object 



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# File 'lib/echonest/api.rb', line 68

def get_tempo(filename)
  get_analysys(:get_tempo, filename) do |analysis|
    analysis.first.content.to_f
  end
end

#get_time_signature(filename) ⇒ Object 



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# File 'lib/echonest/api.rb', line 138

def get_time_signature(filename)
  get_analysys(:get_time_signature, filename) do |analysis|
    ValueWithConfidence.new(analysis.first.content.to_i, analysis.first['confidence'].to_f)
  end
end

#get_trackinfo(method, filename, &block) ⇒ Object 



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# File 'lib/echonest/api.rb', line 156

def get_trackinfo(method, filename, &block)
  content = open(filename).read
  md5 = Digest::MD5.hexdigest(content)

  begin
    response = request(method, :md5 => md5)

    block.call(response)
  rescue Echonest::Api::Error => e
    case e.message
    when /Analysis not ready/
      sleep 20 # wait for serverside analysis
      get_trackinfo(method, filename, &block)
    when 'Invalid parameter: unknown MD5 file hash'
      upload(filename)
      sleep 60 # wait for serverside analysis
      get_trackinfo(method, filename, &block)
    else
      raise
    end
  end
end

#request(name, params) ⇒ Object 



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# File 'lib/echonest/api.rb', line 185

def request(name, params)
  method = (name == :upload ? 'post' : 'get')
  response_body = @user_agent.__send__(method + '_content', URI.join(BASE_URL, name.to_s), build_params(params))
  response = Response.new(response_body)

  unless response.success?
    raise Error.new(response.status.message)
  end

  response
end

#upload(filename) ⇒ Object 



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# File 'lib/echonest/api.rb', line 179

def upload(filename)
  open(filename) do |f|
    request(:upload, :file => f)
  end
end