/// <summary>
/// Attempts to initiate a data stream with the XMPP entity with the specified
/// JID.
/// </summary>
/// <param name="to">The JID of the XMPP entity to initiate a data-stream
/// with.</param>
/// <param name="mimeType">The MIME type of the data to be transferred across
/// the stream.</param>
/// <param name="profile">The 'Stream Initiation' profile to use.</param>
/// <param name="streamOptions">An enumerable collection of supported
/// stream methods which are advertised to the receiving XMPP
/// entity.</param>
/// <param name="data">An XML element containing any additional data the
/// specified 'Stream Initiation' profile may require.</param>
/// <param name="cb">A callback method to invoke once the result of the
/// stream-initation operation has been received.</param>
/// <returns>An initialized instance of the InitiationResult class containing
/// the negotiated stream-method and session identifier.</returns>
/// <exception cref="ArgumentNullException">The to parameter or the mimeType
/// parameter or the profile parameter or the streamOptions parameter
/// is null.</exception>
/// <exception cref="ArgumentException">The streamOptions enumerable contains
/// no elements, or the stream-initiation response received contained no
/// selection for the stream-method.</exception>
/// <exception cref="NotSupportedException">The XMPP entity with
/// the specified JID does not support the 'Stream Initiation' XMPP
/// extension.</exception>
public void InitiateStreamAsync(Jid to, string mimeType, string profile,
IEnumerable <string> streamOptions, XmlElement data = null,
Action <InitiationResult, Iq> cb = null)
{
to.ThrowIfNull("to");
mimeType.ThrowIfNull("mimeType");
profile.ThrowIfNull("profile");
streamOptions.ThrowIfNull("streamOptions");
if (streamOptions.Count() == 0)
{
throw new ArgumentException("The streamOptions enumerable must " +
"include one or more stream-options.");
}
if (!ecapa.Supports(to, Extension.StreamInitiation))
{
throw new NotSupportedException("The XMPP entity does not support " +
"the 'Stream Initiation' extension.");
}
string sid = GenerateSessionId();
var si = CreateSiElement(sid, mimeType, profile, streamOptions, data);
// Perform the actual request.
im.IqRequestAsync(IqType.Set, to, im.Jid, si, null, (id, iq) => {
if (cb == null)
{
return;
}
InitiationResult result = null;
if (iq.Type != IqType.Error)
{
// Result must contain a 'feature' element.
var feat = iq.Data["si"]["feature"];
string selected = ParseStreamMethod(feat);
// Construct the initiation result and call the provided callback.
result = new InitiationResult(sid, selected, iq.Data["si"]);
}
cb(result, iq);
});
}
/// <summary>
/// Invoked once the result of a pending stream-initiation operation has been
/// received.
/// </summary>
/// <param name="result">The result of the stream-initiation operation. If
/// this parameter is null, stream-initiation failed.</param>
/// <param name="to">The JID of the XMPP user to offer the file to.</param>
/// <param name="stream">The stream to read the file-data from.</param>
/// <param name="name">The name of the file, as offered to the XMPP user
/// with the specified JID.</param>
/// <param name="size">The number of bytes to transfer.</param>
/// <param name="cb">A callback method invoked once the other site has
/// accepted or rejected the file-transfer request.</param>
/// <param name="description">A description of the file so the receiver can
/// better understand what is being sent.</param>
/// <remarks>This is called in the context of an arbitrary thread.</remarks>
void OnInitiationResult(InitiationResult result, Jid to, string name,
Stream stream, long size, string description, Action <bool, FileTransfer> cb)
{
FileTransfer transfer = new FileTransfer(im.Jid, to, name, size, null,
description);
try {
// Get the instance of the data-stream extension that the other site has
// selected.
IDataStream ext = im.GetExtension(result.Method) as IDataStream;
// Register the session.
SISession session = new SISession(result.SessionId, stream, size, false,
im.Jid, to, ext);
siSessions.TryAdd(result.SessionId, session);
// Store the file's meta data.
metaData.TryAdd(result.SessionId, new FileMetaData(name, description));
// Invoke user-provided callback.
if (cb != null)
{
cb.Invoke(true, transfer);
}
// Perform the actual data-transfer.
try {
ext.Transfer(session);
} catch (Exception e) {
// Nothing to do here.
}
} catch {
// Something went wrong. Invoke user-provided callback to let them know
// the file-transfer can't be performed.
if (cb != null)
{
cb.Invoke(false, transfer);
}
}
}