void DiscoverRsdOnPage(string webAPI, TextReader streamReader, TaskCompletionSource <DiscoveryResult> taskCompletionSource)
{
const string linkTagRegex = "(?<link>\\<link .*?type=\"application/rsd\\+xml\".*?/\\>)";
var response = streamReader.ReadToEnd();
var link = Regex.Match(response, linkTagRegex, RegexOptions.IgnoreCase);
var rsdLinkMatch = link.Groups["link"];
if (!rsdLinkMatch.Success)
{
taskCompletionSource.SetResult(DiscoveryResult.Failed("Unable to resolve link to rsd file from url"));
return;
}
var rsdLocationMatch = Regex.Match(rsdLinkMatch.Value, "href=(?:\"|')(?<link>.*?)(?:\"|')");
if (!rsdLocationMatch.Groups["link"].Success)
{
taskCompletionSource.SetResult(DiscoveryResult.Failed("Unable to parse rsd link tag"));
return;
}
var rsdUri = new Uri(rsdLocationMatch.Groups["link"].Value, UriKind.RelativeOrAbsolute);
if (!rsdUri.IsAbsoluteUri)
{
rsdUri = new Uri(new Uri(webAPI, UriKind.Absolute), rsdUri);
}
var rdsWebRequest = webRequestFactory.Create(rsdUri);
var rdsWebRequestTask = rdsWebRequest.GetResponseAsync();
// Add a continuation that will only execute if the request succeeds and continues processing the RSD
rdsWebRequestTask.ContinueWith(rdsWebRequestAntecedent =>
taskCompletionSource.SetResult(ProcessRsdResponse(rdsWebRequestAntecedent)),
TaskContinuationOptions.NotOnFaulted);
// Add a continuation that will only execute if the request faults and propagates the exception via the TCS
rdsWebRequestTask.ContinueWith(rdsWebRequestAntecdent =>
taskCompletionSource.SetResult(new DiscoveryResult(rdsWebRequestAntecdent.Exception)),
TaskContinuationOptions.ExecuteSynchronously | TaskContinuationOptions.OnlyOnFaulted);
}
static DiscoveryResult ProcessRsdResponse(Task <WebResponse> webResponseTask)
{
if (webResponseTask.IsFaulted)
{
return(new DiscoveryResult(webResponseTask.Exception));
}
try
{
using (var webResponse = webResponseTask.Result)
{
using (var responseStream = webResponse.GetResponseStream())
{
var document = XDocument.Load(responseStream);
var apiElement = GetMetaWebLogElement(document);
if (apiElement == null)
{
return(DiscoveryResult.Failed("Unable to get metaweblog api address from rds.xml"));
}
var xAttribute = apiElement.Attribute("apiLink");
if (xAttribute == null)
{
return(DiscoveryResult.Failed("apiLink attribute not present for metaweblog api reference"));
}
var webApiLink = xAttribute.Value;
return(new DiscoveryResult(webApiLink));
}
}
}
catch (Exception ex)
{
return(new DiscoveryResult(ex));
}
}
