description

# responseHeaders property Null safety

Map<String, String> responseHeaders

Returns all response headers as a key-value map.

Multiple values for the same header key can be combined into one, separated by a comma and a space.

See: http://www.w3.org/TR/XMLHttpRequest/#the-getresponseheader()-method

## Implementation

    Map<String, String> get responseHeaders {
      // from Closure's goog.net.Xhrio.getResponseHeaders.
      var headers = <String, String>{};
      var headersString = this.getAllResponseHeaders();
      if (headersString == null) {
        return headers;
      }
      var headersList = headersString.split('\r\n');
      for (var header in headersList) {
        if (header.isEmpty) {
          continue;
        }

        var splitIdx = header.indexOf(': ');
        if (splitIdx == -1) {
          continue;
        }
        var key = header.substring(0, splitIdx).toLowerCase();
        var value = header.substring(splitIdx + 2);
        if (headers.containsKey(key)) {
          headers[key] = '${headers[key]}, $value';
        } else {
          headers[key] = value;
        }
      }
      return headers;
    }