/// <summary>
/// This method is used to decode a value read in from a PDI data stream
/// </summary>
/// <param name="data">The data string to decode</param>
/// <returns>The decoded data</returns>
/// <remarks><para>By default, it can handle Base 64 and Quoted-Printable decoding. For 7-bit and 8-bit
/// decoding, it will unescape characters where necessary. The method used depends on the current
/// setting of the <see cref="Encoding"/> property. It can be overridden to support other types of
/// decoding.</para>
///
/// <para>For vCard 2.1 and vCalendar 1.0 properties, if a <see cref="CharacterSet"/> parameter has been
/// specified, the value is converted from the specified character set to the one specified by the
/// <see cref="DefaultEncoding"/> property after decoding.</para></remarks>
public virtual string Decode(string data)
{
string decoded;
// It's only done if the value is inline, text, or binary
if (this.ValueLocation != ValLocValue.Inline && this.ValueLocation != ValLocValue.Text &&
this.ValueLocation != ValLocValue.Binary)
{
return(data);
}
switch (this.EncodingMethod)
{
case EncodingType.SevenBit:
case EncodingType.EightBit:
// Unescape characters for these if necessary
decoded = EncodingUtils.Unescape(data);
break;
case EncodingType.QuotedPrintable:
decoded = EncodingUtils.FromQuotedPrintable(data);
break;
case EncodingType.Base64:
case EncodingType.BEncoding:
// Base 64 decoding
decoded = EncodingUtils.FromBase64(data);
break;
default: // Custom, can't do anything with it
decoded = data;
break;
}
if (String.Compare(this.CharacterSet, CharSetValue.ASCII, StringComparison.OrdinalIgnoreCase) != 0)
{
// The string is already encoded. We just want the bytes in array form
Encoding enc = Encoding.GetEncoding("iso-8859-1");
byte[] srcBytes = enc.GetBytes(decoded);
decoded = defaultEncoding.GetString(Encoding.Convert(Encoding.GetEncoding(this.CharacterSet),
defaultEncoding, srcBytes));
}
return(decoded);
}
