Google Spreadsheets - Wolfram Alpha nutrition data

var WOLFRAM_KEY = "<API KEY GOES HERE>";

var local_cache = {};

function wolfram_api_call(query, key) {
  var response = UrlFetchApp.fetch("http://api.wolframalpha.com/v2/query?input=" + encodeURIComponent(query) + "&appid=" + key + "&format=plaintext");
  
  var xml = XmlService.parse(response);
  var root = xml.getRootElement();
  
  return root;
}

function _get_pod_plaintext(xml) {
  var success = xml.getAttribute("success");
  
  if (success) {
    var children = xml.getChildren();
    
    for (var i = 0; i < children.length; i++) {
      var elem = children[i];
      var title_attr = elem.getAttribute("title");
      if (title_attr != null && title_attr.getValue() == "Average nutrition facts" || title_attr.getValue() == "Nutrition facts") {
        return elem.getChild("subpod").getChild("plaintext").getText();
      }
    }
    
    return null;
  } else {
    return null;
  }
}

function _weight_unit_mult(unit_str) {
  if(unit_str == "g") { return 1; }
  if(unit_str == "mg") { return 0.001; }
  if(unit_str == "kg") { return 1000; }
}

function _get_plaintext(food) {
  var cache = CacheService.getPublicCache();
  
  var cached = cache.get("wa_food_data_" + food)
  var text = null;
  
  if (cached != null && cached != "") {
    text = cached;
  } else {
    var xml = wolfram_api_call("1000g " + food + " food", WOLFRAM_KEY);
    text = _get_pod_plaintext(xml);
    cache.put("wa_food_data_" + food, text, 7 * 24 * 60 * 60);
  }
  
  return text;
}

function _wolfram_nutrition_facts(food) {
  var text = _get_plaintext(food);
  
  var calories=0, fat=0, carbs=0, protein=0;
  
  var lines = text.split(/\r?\n/);
  
  for(var i=0; i < lines.length; i++) {
    var line = lines[i];
    var split_line = line.split(" ").filter(function(e) { return e != ""; } );
    
    if (line.match("total calories") != null) {
      calories = split_line[2] * 0.001;
    } else if (line.match("total fat") != null) {
      fat = split_line[2] * _weight_unit_mult(split_line[3]) * 0.001;
    } else if (line.match("total carbohydrates") != null) {
      carbs = split_line[2] * _weight_unit_mult(split_line[3]) * 0.001;
    } else if (line.match("protein") != null) {
      protein = split_line[1] * _weight_unit_mult(split_line[2]) * 0.001;
    }
  }
  
  return [calories, fat, carbs, protein];
}

function _nutrition_data(food) {
  if (food == "" || food == null) { return ["", "", "", ""]; }
  
  if (local_cache[food] == null) {
    local_cache[food] = _wolfram_nutrition_facts(food);
  }
  return local_cache[food];
}


// Actual methods to use. Unit is grams
function calories(food) {
  return _nutrition_data(food)[0];
}
function fat(food) {
  return _nutrition_data(food)[1];
}
function carbs(food) {
  return _nutrition_data(food)[2];
}
function protein(food) {
  return _nutrition_data(food)[3];
}