/// <summary>
/// Internal callback method that fired when twin json is changed on server side
/// </summary>
private async Task OnDesiredPropertiesUpdate(TwinCollection desiredProperties, object userContext)
{
try
{
Console.WriteLine("Desired property change:");
Console.WriteLine(JsonConvert.SerializeObject(desiredProperties));
//Checking that changed properties is related to blob extended properties
if (desiredProperties[blobConfigPropertyName] != null)
{
var ts = desiredProperties[blobConfigPropertyName]["ts"].Value;
string sasUri = desiredProperties[blobConfigPropertyName]["uri"].Value;
if (string.IsNullOrWhiteSpace(sasUri))
{
Console.WriteLine("Unable to apply blob update: uri is null or whitespace.");
return;
}
if (ts <= lastTimestamp && string.Compare(sasUri, lastUri, true) == 0)
{
Console.WriteLine("Skipping blob update: for the same sas uri, the ts is less than or equal to the currently applied configuration.");
return;
}
lastContent = await DownloadBlobAsync(sasUri);
lastTimestamp = ts;
lastUri = sasUri;
BlobPropertyUpdatedArgs args = new BlobPropertyUpdatedArgs();
args.BlobContent = lastContent;
args.DateTimeUpdated = ts;
//Raise event
OnBlobPropertyUpdatedEvent(args, this);
//Notify IoT hub twin json file that we successfully download the extended blob file
await NotifyIoTHubOfUpdatedBlob(sasUri, ts.ToString("o"));
}
}
catch (AggregateException ex)
{
foreach (Exception exception in ex.InnerExceptions)
{
Console.WriteLine();
Console.WriteLine("Error when receiving desired property: {0}", exception);
}
}
catch (Exception ex)
{
Console.WriteLine();
Console.WriteLine("Error when receiving desired property: {0}", ex.Message);
}
}
protected virtual void OnBlobPropertyUpdatedEvent(BlobPropertyUpdatedArgs e, object sender)
{
var BlobPropertyUpdatedEvent = this._BlobPropertyUpdatedEvent;
if (BlobPropertyUpdatedEvent == null)
{
return;
}
BlobPropertyUpdatedEvent(e, sender);
}