Spotify Metadata API helpers for jQuery

spotify.js

(function($) {  
  $.grepWithLimit = function( elems, callback, limit, inv  ) {
		var ret = [], retVal;
		inv = !!inv;

		// Go through the array, only saving the items
		// that pass the validator function
		for ( var i = 0, length = elems.length; i < length; i++ ) {
			retVal = !!callback( elems[ i ], i );
			if ( inv !== retVal ) {
				ret.push( elems[ i ] );
			}
			// Break when the limit has been reached
			if ( limit >= ret.length) {
			  break;
			}
		}

		return ret;
	},
})(jQuery);

(function($) {
  var spotifyFunctions = {
    spotifyLookup: function(uri, callback, options) {
      options = $.extend(options, {});
      var data = { uri: uri };
      if (options.extras) data['extras'] = options.extras
      return $.get('http://ws.spotify.com/lookup/1/', data, callback, options.dataType || 'json');
    },

    spotifySearch: function(query, callback, options) {
      if (options == null) options = $.extend(options, {})
      
      if ($.isArray(query)) {
        return $.each(query, function(query, i) {
          return $.spotifySearch(query, callback, options)
        })
      } else {
        var data = { q: query, page: options.page || 1 };
                
        return $.get('http://ws.spotify.com/search/1/' + (options.method || 'track'), data, callback, options.dataType || 'json')
      }
    },
    
    filterTracksByCountryCode: function(tracks, twoLetterCountryCode, limit) {
      
      if (limit) {
        limit = 100;
      }
      
      if (twoLetterCountryCode == 'UK') {
        twoLetterCountryCode = 'GB';
      }
      
      return $.grepWithLimit(tracks, function(track, i) {
        return track.album.availability.territories.search(twoLetterCountryCode) >= 0;
      }, limit);
    },

    spotifyArtistSearch: function(query, data, callback) {
      return jQuery.spotifySearch(query, callback, $.extend(data, { method: 'artist' }));
    },

    spotifyAlbumSearch: function(query, data, callback) {
      return jQuery.spotifySearch(query, callback, $.extend(data, { method: 'album' }));
    }
  }
  
  $.extend(spotifyFunctions);

  $.spotifyTrackSearch = $.spotifySearch;
})(jQuery);