“Cloudy with a chance of file uploads” or how to successfully upload files to Azure, Amazon S3 and Telerik Everlive in ASP.NET

With the Q3 2013 release the weather in Telerik’s ASP.NET AJAX suite became a bit cloudy, but the new Cloud Upload control makes the chance of file uploads in Azure, Amazon S3 and Telerik Everlive 100% positive. Try it out—get the new trial product version here or the licensed version from your account and have fun.

Supported providers 

Today marks the official release of Telerik’s own backend-as-a-service solution, Everlive. We hope that it will quickly become the preferred BaaS, especially for Telerik customers, so RadCloudUpload supports it out of the box as well.

Configuration bliss

To upload files you need to setup the control. The easiest way to do it is to use its smart tag. Choose a provider type and then open the configuration wizard. Here are the mandatory settings that should be set for each provider:

• Amazon S3
• Access Key
• Secret Key
• Bucket Name
• Azure
• Account Key
• Account Name
• Blob Container Name
• Telerik Everlive
  • API Key

Keep in mind that you should add a reference to the corresponding provider (e.g. Microsoft.WindowsAzure.StorageClient.dll) to your project. Here you can find detailed information about this. Also the Telerik.Web.UI.WebResource.axd handler should be registered in the web.config. In case that you forget some of the above configurations, the control will kindly remind you with a yellow screen of death.

How does the upload happen?

Under IE9, IE8 andIE7 the control uploads files by submitting “input type=’file‘ ”  element in a separate form to the control’s upload handler. After that the file is transferred to the storage. In the rest of the browsers the files are uploading on chunks to RadCloudUpload’s handler and after the last chunk is sent the file is assembled in the storage.

What’s great is that no files are kept on the hard drive of the server (even temporary), they are only transferred by the handler to the storage.

Other capabilities of Telerik’s ASP.NET Cloud Upload

We have experience with upload controls and we included the features we know are most valuable for our customers in the Cloud Upload, too.

• File Validation
• Multiple-file Selection
• Client-Side Events
• Information panel

Short Q&A

Q: What happens with the uploaded chunks, if the upload fails?
A: The control triggers a method from the application’s cache after a certain time to delete the chunks.

Q: What will happen with the uploaded files, if they are not processed after a postback (e.g. a user has an account and uploads images, but closes the browser without submitting the page)?
A: The answer here is similar to the previous one. The control triggers a method from the application’s cache after a certain time to delete the files if they are not processed after a postback.
(If you have experience with Telerik’s ASP.NET file upload control this will sound familiar to you)

Q: Are my configuration keys secured?
A: Yes, they are. All the configuration settings are kept in the web.config file.

Q: Why do I need to use a handler to double my traffic, if I am using a modern browser where CORS is available?
A: Because we need to support the old browsers. But keep calm because this is a feature that is in RadCloudUpload’s roadmap for the next releases.

Q: What is coming next?
A: Drag and Drop support.

Feedback please