Uri.splitQueryString only return the last value if parameter is entered multiple times

[rwrozelle]

SplitQueryString only returns the last value if the parameter is entered multiple times, for example:
"foo=bar&fi=fo&fi=fum" returns {"foo": "bar", "fi": "fum"}
I would prefer it to return a list of strings: {"foo": "bar", "fi":["fo","fum"]}

Below is example code of the type of change I would like, this is just an example, so please ammend if a more concise change would be more appropriate:

  Static Map<String, Object> splitQueryString(String query, 
                                              {Encoding encoding: UTF8}) {
    return query.split("&").fold({}, (map, element) {
      int index = element.indexOf("=");
      if (index == -1) {
        if (element != "") {
          map[Uri.decodeQueryComponent(element, encoding: encoding)] = "";
        }
      } else if (index != 0) {
        var key = element.substring(0, index);
        var value = element.substring(index + 1);
        String decodedKey = Uri.decodeQueryComponent(key, encoding: encoding);
        String decodedValue = Uri.decodeQueryComponent(value, encoding: encoding);
        if (map[decodedKey] == null) {
          map[decodedKey] = decodedValue;
        }
        else {
          if (map[decodedKey] is List) {
            List<String> listValue = map[decodedKey] as List<String>;
            listValue.add(decodedValue);
          }
          else {
            List<String> listValue = new List<String>();
            listValue.add(map[decodedKey]);
            listValue.add(decodedValue);
            map[decodedKey] = listValue;
          }
        }
      }
      return map;
    });
  }

[lrhn]

That would be a breaking change at this point, so it would be better to add a separate function with the new functionality.

That function doesn't actually need to be on Uri, it could also just be added to a helper package

[bobjackman]

+1

[lrhn]

You can now use the queryParametersAll method which returns a Map<String,List<String>>. That does mean that all query values are returned as lists, even those that only have one element.