/// <summary>
/// Creates a <see cref="XPathNavigator"/> against the supplied <see cref="Stream"/>.
/// </summary>
/// <param name="stream">The <see cref="Stream"/> object that contains the XML data to be navigated by the created <see cref="XPathNavigator"/>.</param>
/// <returns>
/// An <see cref="XPathNavigator"/> that provides a cursor model for navigating the supplied <paramref name="stream"/>.
/// The supplied <paramref name="stream"/> XML data is parsed to remove invalid XML characters that would normally prevent
/// a navigator from being created.
/// </returns>
/// <remarks>
/// The character encoding of the supplied <paramref name="stream"/> is automatically determined based on the <i>encoding</i> attribute of the XML document declaration.
/// If the character encoding cannot be determined, a default encoding of <see cref="Encoding.UTF8"/> is used.
/// </remarks>
/// <exception cref="ArgumentNullException">The <paramref name="stream"/> is a null reference (Nothing in Visual Basic).</exception>
public static XPathNavigator CreateSafeNavigator(Stream stream)
{
//------------------------------------------------------------
// Local members
//------------------------------------------------------------
Encoding encoding = Encoding.UTF8;
byte[] buffer = null;
//------------------------------------------------------------
// Validate parameter
//------------------------------------------------------------
Guard.ArgumentNotNull(stream, "stream");
//------------------------------------------------------------
// Extract stream data as an array of bytes
//------------------------------------------------------------
buffer = SyndicationEncodingUtility.GetStreamBytes(stream);
//------------------------------------------------------------
// Determine encoding of the XML data
//------------------------------------------------------------
encoding = SyndicationEncodingUtility.GetXmlEncoding(buffer);
//------------------------------------------------------------
// Attempt to return navigator for supplied stream
//------------------------------------------------------------
using (MemoryStream memoryStream = new MemoryStream(buffer))
{
return(SyndicationEncodingUtility.CreateSafeNavigator(memoryStream, encoding));
}
}
/// <summary>
/// Returns an <see cref="Encoding"/> that represents the XML character encoding for the supplied <see cref="Stream"/>.
/// </summary>
/// <param name="stream">A <see cref="Stream"/> that represents an XML data source to determine the character encoding for.</param>
/// <returns>
/// A <see cref="Encoding"/> that represents the character encoding specified by the XML data source.
/// If the character encoding is not specified or unable to be determined, returns <see cref="Encoding.UTF8"/>.
/// </returns>
/// <exception cref="ArgumentNullException">The <paramref name="stream"/> is a null reference (Nothing in Visual Basic).</exception>
public static Encoding GetXmlEncoding(Stream stream)
{
//------------------------------------------------------------
// Validate parameter
//------------------------------------------------------------
Guard.ArgumentNotNull(stream, "stream");
//------------------------------------------------------------
// Read the stream contents and return character encoding
//------------------------------------------------------------
using (StreamReader reader = new StreamReader(stream))
{
return(SyndicationEncodingUtility.GetXmlEncoding(reader.ReadToEnd()));
}
}
//puke
///// <summary>
///// Extracts the character encoding for the content type of the supplied <see cref="HttpRequest"/>.
///// </summary>
///// <param name="request">The HTTP values sent by a client during a Web request.</param>
///// <returns>
///// A <see cref="Encoding"/> that represents character encoding of the Content-Type <i>charset</i> attribute.
///// If the <i>charset</i> attribute is unavailable or invalid, returns <b>null</b>.
///// </returns>
///// <exception cref="ArgumentNullException">The <paramref name="request"/> is a null reference (Nothing in Visual Basic).</exception>
//public static Encoding GetCharacterEncoding(HttpRequest request)
//{
// //------------------------------------------------------------
// // Local members
// //------------------------------------------------------------
// Encoding contentEncoding = null;
// //------------------------------------------------------------
// // Validate parameter
// //------------------------------------------------------------
// Guard.ArgumentNotNull(request, "request");
// //------------------------------------------------------------
// // Extract character encoding from HTTP request
// //------------------------------------------------------------
// if (!String.IsNullOrEmpty(request.ContentType))
// {
// if (request.ContentType.Contains(";"))
// {
// string[] contentTypeParts = request.ContentType.Split(";".ToCharArray(), StringSplitOptions.RemoveEmptyEntries);
// if (contentTypeParts != null && contentTypeParts.Length > 0)
// {
// for (int i = 0; i < contentTypeParts.Length; i++)
// {
// string typePart = contentTypeParts[i].Trim();
// if (typePart.Contains("="))
// {
// string[] nameValuePair = typePart.Split("=".ToCharArray(), StringSplitOptions.RemoveEmptyEntries);
// if (nameValuePair != null && nameValuePair.Length == 2)
// {
// string name = nameValuePair[0].Trim();
// string value = nameValuePair[1].Trim();
// if (String.Compare(name, "charset", StringComparison.OrdinalIgnoreCase) == 0)
// {
// try
// {
// contentEncoding = Encoding.GetEncoding(value);
// }
// catch (ArgumentException)
// {
// return null;
// }
// }
// }
// }
// }
// }
// }
// }
// return contentEncoding;
//}
#endregion
#region GetXmlEncoding(byte[] data)
/// <summary>
/// Returns an <see cref="Encoding"/> that represents the XML character encoding for the supplied array of bytes.
/// </summary>
/// <param name="data">An array of bytes that represents an XML data source to determine the character encoding for.</param>
/// <returns>
/// A <see cref="Encoding"/> that represents the character encoding specified by the XML data source.
/// If the character encoding is not specified or unable to be determined, returns <see cref="Encoding.UTF8"/>.
/// </returns>
/// <exception cref="ArgumentNullException">The <paramref name="data"/> is a null reference (Nothing in Visual Basic).</exception>
public static Encoding GetXmlEncoding(byte[] data)
{
//------------------------------------------------------------
// Validate parameter
//------------------------------------------------------------
Guard.ArgumentNotNull(data, "data");
//------------------------------------------------------------
// Create stream using data and return character encoding
//------------------------------------------------------------
using (MemoryStream stream = new MemoryStream(data))
{
return(SyndicationEncodingUtility.GetXmlEncoding(stream));
}
}