public Task <ContentProviderResult> ExtractResource(string url)
{
Uri resultUrl;
if (Uri.TryCreate(url, UriKind.Absolute, out resultUrl))
{
var request = new ContentProviderHttpRequest(resultUrl);
return(ExtractContent(request));
}
return(TaskAsyncHelper.FromResult <ContentProviderResult>(null));
}
protected override Task <ContentProviderResult> GetCollapsibleContent(ContentProviderHttpRequest request)
{
var args = ExtractParameters(request.RequestUri);
if (args == null || !args.Any())
{
return(TaskAsyncHelper.FromResult <ContentProviderResult>(null));
}
return(TaskAsyncHelper.FromResult(new ContentProviderResult()
{
Content = String.Format(MediaFormatString, args.ToArray()),
Title = request.RequestUri.AbsoluteUri
}));
}
public virtual Task <ContentProviderResult> GetContent(ContentProviderHttpRequest request)
{
return(GetCollapsibleContent(request).Then(result =>
{
if (IsCollapsible && result != null)
{
result.Content = String.Format(CultureInfo.InvariantCulture,
ContentFormat,
IsPopOut ? @"<div class='collapsible_pin'></div>" : "",
result.Title,
result.Content);
}
return result;
}));
}
private Task <ContentProviderResult> ExtractContent(ContentProviderHttpRequest request)
{
var contentProviders = _contentProviders.Value;
var validProviders = contentProviders.Where(c => c.IsValidContent(request.RequestUri))
.ToList();
if (validProviders.Count == 0)
{
return(TaskAsyncHelper.FromResult <ContentProviderResult>(null));
}
var tasks = validProviders.Select(c => c.GetContent(request)).ToArray();
var tcs = new TaskCompletionSource <ContentProviderResult>();
Task.Factory.ContinueWhenAll(tasks, completedTasks =>
{
var faulted = completedTasks.FirstOrDefault(t => t.IsFaulted);
if (faulted != null)
{
tcs.SetException(faulted.Exception);
}
else if (completedTasks.Any(t => t.IsCanceled))
{
tcs.SetCanceled();
}
else
{
ContentProviderResult result = completedTasks.Select(t => t.Result)
.FirstOrDefault(content => content != null);
tcs.SetResult(result);
}
});
return(tcs.Task);
}
protected abstract Task <ContentProviderResult> GetCollapsibleContent(ContentProviderHttpRequest request);