/// <param name="headerValue">A raw string header value.</param>
/// <returns>A collection of header values with quality.</returns>
public static HeaderValuesWithQualityCollection Parse(string headerValue)
{
var result = new HeaderValuesWithQualityCollection();
if (string.IsNullOrEmpty(headerValue))
{
return(result);
}
if (!ValueFormat.IsMatch(headerValue))
{
throw new FormatException($"Invalid header value: '{headerValue}'.");
}
var headerValueParts = headerValue.Split(ValueSeparator, StringSplitOptions.RemoveEmptyEntries);
foreach (var valueWithQuality in headerValueParts)
{
var valueQuality = valueWithQuality.Split(QualitySeparator, StringSplitOptions.RemoveEmptyEntries);
if (valueQuality.Length < 1 || valueQuality.Length > 2)
{
throw new FormatException($"Invalid header value format at '{valueWithQuality}'");
}
var value = valueQuality.FirstOrDefault();
if (valueQuality.Length < 2 ||
!decimal.TryParse(valueQuality[1].Split(QualityValueSeparator, StringSplitOptions.RemoveEmptyEntries).LastOrDefault(), NumberStyles.Number, NumberFormatInfo.InvariantInfo, out var quality))
{
quality = 1m;
}
result.Add(value, quality);
}
return(result);
}
public static Request AppendToHeaderWithQuality([NotNull] this Request request, [NotNull] string name, [NotNull] string value, decimal quality = 1)
{
var currentValue = request.Headers?[name];
if (string.IsNullOrEmpty(currentValue))
{
return(request.WithHeader(name, new HeaderValueWithQuality(value, quality)));
}
var valueCollection = HeaderValuesWithQualityCollection.Parse(currentValue);
valueCollection.Add(value, quality);
return(request.WithHeader(name, valueCollection.ToString()));
}