What i learned today.

Working with ASP.Net and SilverLight in my current project i learned two important things today

SL will always show generic NotFound exception for a remote call failures irrespective of what was returned from server. This limitation roots in the browser which does not pass the exception details to the SL plugin. The only way around is to always send a responses which have Fault property for the SL client to work with.
ASP.Net forms authentication mechanism always redirects on 404 error and behaviour is hard to change. This becomes a problem working with SL or ASP.Net MVC clients which expect Http error code (REST clients). The workaround that i found on Stackoverflow was to thrown 403 Error Code instead of 401. This way service calls made from SL or ASP.Net MVC can return http status codes (REST endpoints) and will not cause server redirects.

Comments

Caching Images downloaded from web on Windows Phone Isolated storage

I was helping on a Windows Phone application where the requirement was to cache the images the phone downloads on the isolated storage for offline viewing. I wanted a solution which was simple and as transparent as possible. While researching I found someone wrote a Silverlight converter for loading images from isolated storage. Taking that as a base I created a converted which can Load image from web (http + https), and persist it to isolated storage. In case of network connectivity issues can load the same image from isolated storage. It does that by mapping the http url to a isolated storage location. In case the network is down and the image is neither there in cache, loads a default image, passed as parameter to converter. Here is the gist for the implementation. To use the converter Import the name space. Declare the converter as resource. Set the Image Source Property to use this converter like this

Integrating ASP.Net MVC with AngularJS

We recently released a Project Template for ASP.Net MVC and AngularJS here and here . I did a follow up post detailing how the project template has been setup and how to make AngularJS and MVC play well together on my company blog . If you are interested in understanding how the template works head over to my blog post and read it!

IIS Url Rewrite and HTTP POST data

If you play around with IIS Url Rewriting rules and try to do redirects on an HTTP POST you loose your POST data. To make sure you get the post data you have to set the `redirectType` to `Temporary` within your rules. So the action configuration looks like this <action redirectType=" Temporary " type="Redirect" url="http://{HTTP_HOST}{REQUEST_URI}"> </action> You may think what scenario warrant a POST request redirect. We faced one such scenario while doing SSO with a federated Identity Provider (IP) such as Google, Azure AD. In federated authentication scenario once the user is authenticated by the IP, it redirects back to your site with claim tokens in a POST request over secure channel (https). In our case we wanted to redirect to user back http after receiving the request. But any redirects were causing loss of token. By doing a 307 (Temporary) redirect we were able to preserve the post data.

Random Thoughts

Search This Blog