jquery-music-preview.js

/*
 * Author: Yves Van Broekhoven
 * Created at: 2012-02-01
 * Version: 1.0.0
 * API docs: http://developer.echonest.com/
 * jPlayer docs: http://jplayer.org/
 *
 * @example
 *   $.musicPreview('lady gaga', 'born this way');
 * 
 */
(function($){
  
  var api_key   = 'QNR9YFKVAPUN3PGLL'
  ,   url       = 'http://developer.echonest.com/api/v4/song/search?api_key={{api_key}}&format=json&results=1&artist={{artist}}&title={{title}}&bucket=id:7digital-US&bucket=audio_summary&bucket=tracks'
  ,   response  = {}
  ;

  var _onSuccess
  ;

  $.musicPreview = function(artist, title){
  
    var dfd = $.Deferred();
  
    // Error: artist required
    if (artist === undefined || artist == '') {
      return dfd.reject(response.artist_required);
    }
  
    // Error: song title required
    if (title === undefined || title == '') {
      return dfd.reject(response.title_required);
    }
  
    // Echonest request
    var api_url = url.replace('{{api_key}}', api_key)
                     .replace('{{artist}}', artist)
                     .replace('{{title}}', title);
  
    var jxhr = $.getJSON(api_url);
  
  
    // Success: Echnonest request
    jxhr.success(function(data){
      _onSuccess.call(dfd, data);
    });
  
    // Error: Echnonest request
    jxhr.error(function(data){
      dfd.reject($.extend({}, response.request_error, { data: data }));
    });
  
    return dfd.promise();
  };


  _onSuccess = function(data){
  
    // Error: No songs found
    if (data.response.songs.length <= 0) {
      return this.reject(response.no_songs_found);
    }
  
    // Error: No preview found
    if (data.response.songs[0].tracks === undefined || data.response.songs[0].tracks.length <= 0) {
      return this.reject(response.no_preview_found);
    }
  
    // Success: preview found
    var preview_url = data.response.songs[0].tracks[0].preview_url;
    return this.resolve($.extend({}, response.success, { preview_url: preview_url }));
  
  };

  response = {
  
    artist_required: {
      status:   'error'
    , message:  'Artist required'
    },
  
    title_required: {
      status:   'error'
    , message:  'Song title required'
    },
  
    requeset_error: {
      status:   'error'
    , message:  'Can not connect to Echonest API'
    },
  
    no_songs_found: {
      status:   'error'
    , message:  'No soungs found'
    },
  
    no_preview_found: {
      status:   'error'
    , message:  'No preview found'
    },
  
    success: {
      status:   'success'
    , message:  'Preview found'
    }
  
  };

  
}(jQuery));