private static char GetSeparator(FieldValueSeparator separator)
{
switch (separator)
{
case FieldValueSeparator.Ampersand:
return('&');
case FieldValueSeparator.Semicolon:
return(';');
}
throw new ArgumentOutOfRangeException(nameof(separator));
}
/// <summary>
/// Combines the specified query string, header or a form-data <paramref name="sources"/> into one <see cref="NameValueCollection"/> equivalent field-value pairs.
/// </summary>
/// <param name="sources">A variable number of query string, header or a form-data <paramref name="sources"/> to combine into one <see cref="NameValueCollection"/>.</param>
/// <param name="separator">The <see cref="FieldValueSeparator"/> to use in the combination.</param>
/// <returns>A variable number of query string, header or a form-data <paramref name="sources"/> combined into one <see cref="NameValueCollection"/> equivalent field-value pairs.</returns>
internal static NameValueCollection CombineFieldValuePairs(FieldValueSeparator separator, params NameValueCollection[] sources)
{
if (sources == null)
{
throw new ArgumentNullException(nameof(sources));
}
StringBuilder mergedFieldValuePairs = new StringBuilder(separator == FieldValueSeparator.Ampersand ? "?" : "");
foreach (NameValueCollection fieldValuePairs in sources)
{
if (fieldValuePairs.Count == 0)
{
continue;
}
mergedFieldValuePairs.Append(separator == FieldValueSeparator.Ampersand ? ParseFieldValuePairs(fieldValuePairs, separator, true).Remove(0, 1) : ParseFieldValuePairs(fieldValuePairs, separator, true));
mergedFieldValuePairs.Append(GetSeparator(separator));
}
if (mergedFieldValuePairs.Length > 0)
{
mergedFieldValuePairs.Remove(mergedFieldValuePairs.Length - 1, 1);
}
return(ParseFieldValuePairs(mergedFieldValuePairs.ToString(), separator, false));
}
/// <summary>
/// Parses a query string, header or a form-data into a <see cref="String"/> equivalent field-value pairs as specified by the W3C.
/// </summary>
/// <param name="fieldValuePairs">The query string, header or form-data values to parse.</param>
/// <param name="separator">The <see cref="FieldValueSeparator"/> to use in the conversion.</param>
/// <param name="urlEncode">Encodes the output URL string. Default is true.</param>
/// <returns>A <see cref="String"/> value equivalent to the values in the <paramref name="fieldValuePairs"/>.</returns>
internal static string ParseFieldValuePairs(NameValueCollection fieldValuePairs, FieldValueSeparator separator, bool urlEncode)
{
if (fieldValuePairs == null)
{
throw new ArgumentNullException(nameof(fieldValuePairs));
}
char characterSeperator = GetSeparator(separator);
StringBuilder builder = new StringBuilder(separator == FieldValueSeparator.Ampersand ? "?" : "");
foreach (string item in fieldValuePairs)
{
builder.AppendFormat("{0}={1}", item, urlEncode ? HttpUtility.UrlEncode(HttpUtility.UrlDecode(fieldValuePairs[item])) : fieldValuePairs[item]); // the HttpUtility.UrlDecode is called when used outside of IIS .. IIS auto UrlEncode .. why we have to assure, that we don't double UrlEncode ..
builder.Append(characterSeperator);
}
if (builder.Length > 0 && separator == FieldValueSeparator.Ampersand)
{
builder.Remove(builder.Length - 1, 1);
}
return(builder.ToString());
}
/// <summary>
/// Parses a query string, header or a form-data into a <see cref="NameValueCollection"/> equivalent field-value pairs.
/// </summary>
/// <param name="fieldValuePairs">The query string, header or form-data values to parse.</param>
/// <param name="urlDecode">Converts <paramref name="fieldValuePairs"/> that has been encoded for transmission in a URL into a decoded string. Default is false.</param>
/// <param name="separator">The <see cref="FieldValueSeparator"/> to use in the conversion.</param>
/// <returns>A <see cref="NameValueCollection"/> value equivalent to the values in the <paramref name="fieldValuePairs"/>.</returns>
internal static NameValueCollection ParseFieldValuePairs(string fieldValuePairs, FieldValueSeparator separator, bool urlDecode)
{
if (fieldValuePairs == null)
{
throw new ArgumentNullException(nameof(fieldValuePairs));
}
NameValueCollection modifiedFieldValuePairs = new NameValueCollection();
if (fieldValuePairs.Length == 0)
{
return(modifiedFieldValuePairs);
}
char characterSeperator = GetSeparator(separator);
if (separator == FieldValueSeparator.Ampersand && fieldValuePairs.StartsWith("?", StringComparison.OrdinalIgnoreCase))
{
fieldValuePairs = fieldValuePairs.Remove(0, 1);
}
string[] namesAndValues = fieldValuePairs.Split(characterSeperator);
foreach (string nameAndValue in namesAndValues)
{
int equalLocation = nameAndValue.IndexOf("=", StringComparison.OrdinalIgnoreCase);
if (equalLocation < 0)
{
continue;
} // we have no parameter values, just a value pair like lcid=1030& or lcid=1030&test
string value = equalLocation == nameAndValue.Length ? null : urlDecode?HttpUtility.UrlDecode(nameAndValue.Substring(equalLocation + 1)) : nameAndValue.Substring(equalLocation + 1);
modifiedFieldValuePairs.Add(nameAndValue.Substring(0, nameAndValue.IndexOf("=", StringComparison.OrdinalIgnoreCase)), value);
}
return(modifiedFieldValuePairs);
}
