/// <summary>
/// Loads the syndication resource using the specified <see cref="XPathNavigator"/> and <see cref="SyndicationResourceLoadSettings"/>.
/// </summary>
/// <param name="navigator">A read-only <see cref="XPathNavigator"/> object for navigating through the syndication resource information.</param>
/// <param name="settings">The <see cref="SyndicationResourceLoadSettings"/> object used to configure the load operation of the <see cref="AtomFeed"/>.</param>
/// <param name="eventData">A <see cref="SyndicationResourceLoadedEventArgs"/> that contains the event data used when raising the <see cref="AtomFeed.Loaded"/> event.</param>
/// <remarks>
/// After the load operation has successfully completed, the <see cref="AtomFeed.Loaded"/> event is raised using the specified <paramref name="eventData"/>.
/// </remarks>
/// <exception cref="ArgumentNullException">The <paramref name="navigator"/> is a null reference (Nothing in Visual Basic).</exception>
/// <exception cref="ArgumentNullException">The <paramref name="settings"/> is a null reference (Nothing in Visual Basic).</exception>
/// <exception cref="ArgumentNullException">The <paramref name="eventData"/> is a null reference (Nothing in Visual Basic).</exception>
/// <exception cref="FormatException">The <paramref name="navigator"/> data does not conform to the expected syndication content format. In this case, the feed remains empty.</exception>
private void Load(XPathNavigator navigator, SyndicationResourceLoadSettings settings, SyndicationResourceLoadedEventArgs eventData)
{
//------------------------------------------------------------
// Validate parameters
//------------------------------------------------------------
Guard.ArgumentNotNull(navigator, "navigator");
Guard.ArgumentNotNull(settings, "settings");
Guard.ArgumentNotNull(eventData, "eventData");
//------------------------------------------------------------
// Load syndication resource using the framework adapters
//------------------------------------------------------------
SyndicationResourceAdapter adapter = new SyndicationResourceAdapter(navigator, settings);
adapter.Fill(this, SyndicationContentFormat.Atom);
//------------------------------------------------------------
// Raise Loaded event to notify registered handlers of state change
//------------------------------------------------------------
this.OnFeedLoaded(eventData);
}
/// <summary>
/// Called when a corresponding asynchronous load operation completes.
/// </summary>
/// <param name="result">The result of the asynchronous operation.</param>
private static void AsyncLoadCallback(IAsyncResult result)
{
//------------------------------------------------------------
// Local members
//------------------------------------------------------------
System.Text.Encoding encoding = System.Text.Encoding.UTF8;
XPathNavigator navigator = null;
WebRequest httpWebRequest = null;
AtomFeed feed = null;
Uri source = null;
WebRequestOptions options = null;
SyndicationResourceLoadSettings settings = null;
//------------------------------------------------------------
// Determine if the async send operation completed
//------------------------------------------------------------
if (result.IsCompleted)
{
//------------------------------------------------------------
// Extract the send operations parameters from the user state
//------------------------------------------------------------
object[] parameters = (object[])result.AsyncState;
httpWebRequest = parameters[0] as WebRequest;
feed = parameters[1] as AtomFeed;
source = parameters[2] as Uri;
settings = parameters[3] as SyndicationResourceLoadSettings;
options = parameters[4] as WebRequestOptions;
object userToken = parameters[5];
//------------------------------------------------------------
// Verify expected parameters were found
//------------------------------------------------------------
if (feed != null)
{
//------------------------------------------------------------
// Get the response to the syndication resource request
//------------------------------------------------------------
WebResponse httpWebResponse = (WebResponse)httpWebRequest.EndGetResponse(result);
//------------------------------------------------------------
// Load syndication resource
//------------------------------------------------------------
using (Stream stream = httpWebResponse.GetResponseStream())
{
if (settings != null)
{
encoding = settings.CharacterEncoding;
}
using (StreamReader streamReader = new StreamReader(stream, encoding))
{
XmlReaderSettings readerSettings = new XmlReaderSettings();
readerSettings.IgnoreComments = true;
readerSettings.IgnoreWhitespace = true;
readerSettings.ProhibitDtd = false;
using (XmlReader reader = XmlReader.Create(streamReader, readerSettings))
{
if (encoding == System.Text.Encoding.UTF8)
{
navigator = SyndicationEncodingUtility.CreateSafeNavigator(source, options, null);
}
else
{
navigator = SyndicationEncodingUtility.CreateSafeNavigator(source, options, settings.CharacterEncoding);
}
//------------------------------------------------------------
// Load syndication resource using the framework adapters
//------------------------------------------------------------
SyndicationResourceAdapter adapter = new SyndicationResourceAdapter(navigator, settings);
adapter.Fill(feed, SyndicationContentFormat.Atom);
//------------------------------------------------------------
// Raise Loaded event to notify registered handlers of state change
//------------------------------------------------------------
feed.OnFeedLoaded(new SyndicationResourceLoadedEventArgs(navigator, source, options, userToken));
}
}
}
//------------------------------------------------------------
// Reset load operation in progress indicator
//------------------------------------------------------------
feed.LoadOperationInProgress = false;
}
}
}
