How to return a 401 status code using ASP.NET MVC 5 and OWIN

This time I was trying to force users to the login page after an Ajax request failed because of an expired session. I was getting something like this in the response:

X-Responded-JSON: {"status":401,"headers":...
  
I investigated a little and turned out you have to add this code to your Startup.Auth.cs file:

Provider = new CookieAuthenticationProvider

{

  OnApplyRedirect = ctx =>

  {

    if (!IsAjaxRequest(ctx.Request))

    {

       ctx.Response.Redirect(ctx.RedirectUri);

    }

  }

}


Also, in your filter I suggest you do something like this:


if (filterContext.HttpContext.Request.IsAjaxRequest())
{
filterContext.HttpContext.Items["RequestWasNotAuthorized"] = true;
filterContext.HttpContext.Response.StatusCode = 401;
filterContext.HttpContext.Response.End();
filterContext.Result = new HttpUnauthorizedResult();
}

And then handle it in JavaScript like this:

$(document).ajaxError(function (xhr, props) {
if (props.status === 401) {
location.reload();
}
});

More information on the error can be found here:
http://kevin-junghans.blogspot.mx/2013/12/returning-401-http-status-code-on.html
https://brockallen.com/2013/10/27/using-cookie-authentication-middleware-with-web-api-and-401-response-codes/

A connection was successfully established with the server, but then an error occurred during the login process. (provider: Shared Memory Provider, error: 0 - The handle is invalid.)

The solution is simple, just reset IIS. If that doesn't work, this SO question will help

http://stackoverflow.com/questions/3270199/a-connection-was-successfully-established-with-the-server-but-then-an-error-occ

Run Visual Studio as an administrator all the time

Why is it that right-clicking the Visual Studio icon and then clicking Visual studio opens the application as an administrator (after you configure it this way in the properties window) but right-clicking the Visual Studio icon and then clicking a project doesn't? In Windows 8 and 10 you have to follow a few more steps as defined here (http://stackoverflow.com/questions/9654833/how-to-run-visual-studio-as-administrator-by-default)

Right-click devenv.exe and select "Troubleshoot compatibility".

1. select "Troubleshoot program"
2. check "The program requires additional permissions" click "Next", click "Test the program..."
3. wait for the program to launch
4. click "Next"
5. select "Yes, save these settings for this program"
6. click "Close"

Entity Framework - Store update, insert, or delete statement affected an unexpected number of rows (0)

This error can have several causes, in my case it was that I had forgotten to create the PK and identity columns in a table. More complex causes can be found here http://stackoverflow.com/questions/1836173/entity-framework-store-update-insert-or-delete-statement-affected-an-unexpec

PowerShell - "AuthorizationManager check failed" from Octopus Deploy

I came across this error when trying to run Import-Module in an Octopus Deploy PowerShell script. This script was in the source code. What I end up doing was taking out Import-Module into its own Octopus Deploy step "Run a Script".

This article also thoroughly explain the reason for the error http://tgnp.me/2011/09/powershell-authorizationmanager-check-failed-resolution/

In the process, I also learned that Octopus Deploy changes the execution policy of the Powershell process to unrestricted.

Tracking changes in a database in a .NET project

Java has a very neat package to do this, called torque. In .NET we're not quite there yet, so I highly recommend https://github.com/bilal-fazlani/tracker-enabled-dbcontext for .NET projects. Here are some things to keep in mind:

1) It will log all changes into only 2 (master-detail) tables (instead of having as many tables as entities as in torque).
2) You need to create those 2 tables manually, the schema is derived from screenshots in the wiki of the project (don't forget your PK's).
3) Setting it up is quite simple, only annotate the entities you want to track and inherit from TrackerContext instead of DbContext.

Debugging minified code in Chrome's Developer Tools

There are 2 options. The first one is really simple, just go to Developer Tools > Sources > Find the minified script > Click it to open it > Click the {} button on the bottom-left corner of the script. That is going to un-minify the script. In other words, it's going to add a carriage return to make it readable but will still be the same file contents.

The second option is to use the Workspace of the Developer Tools. You can read more about it here https://developers.google.com/web/tools/setup/setup-workflow?hl=en.