Lachlan B's Blog

Speaking at NDC Sydney

In a couple of months I'll be speaking at NDC Sydney - my topic is "How to change things at your company" - a lightning talk on how to enact change. This is a non technical talk, which is fantastic, because I don't fancy having to answer technical questions from such a tough audience!!

This will be my first "big" conference, and I have to thank Lars Klint for his fantastic support in choosing me to speak at the DDD conference last year, which really gave me the confidence to submit a few talks to NDC. I should also link to a great article by Troy Hunt titled Speaker Style Bingo which is a killer article that helped me a lot in preparing my talks. Thanks guys!


Toehider gig with gibson les paul

A few weeks back we did a great gig at the Ding Dong lounge. I borrowed my brother's Gibson Les Paul for a couple of songs and it ROCKED. I have to say.. I'm pretty darn proud of my solo in this video!


Arduino based midi patch changer

I thought it would be fun to build a MIDI patch changer, something like this one.

So I bought a simple arduino kit and started knocking it together. Fortunately I've done a bit of electronics beforehand so I found it quite easy. The prototype has been built:

The next step will be mounting it in a box. Good fun!


Using NuGet to manage shared code

Within your organisation you probably have shared code that is common across multiple projects? You know, code that does boring stuff like sending an email, error message logging or generating a nice bit of HTML.

So the question is, How do you manage that code? Do you:

  1. Copy around code files to multiple projects
  2. Factor out your common code to a new project and include that project in many solutions
  3. Compile down your common project into a DLL and copy that around
  4. Use revision control to import particular versions of common libraries

All of these solutions work, but when it comes to keeping your common code up to date, and knowing which versions are used by which applications, you're going to start running into problems.

Enter, NuGet!

But isn't NuGet what Visual Studio uses for managing external, public packages? Yes it is. But did you know you can host your own private NuGet repository, create your own...

ASP.NET Two Factor Auth with Google's Authenticator App part 2

This is part two in a series of posts. For the introduction post on how to do it all with a NuGet package, see two factor auth with google authenticator app. This article is about how to implement it manually and how it works behind the scenes. A lot of this code is based on an article by Jerrie Pelser titled Using google authenticator with identity.

If you already have an application that is utilising ASP.NET's identity service, you can made a few modifictions to include the Two Factor authentication code.

To show how this can be done, first off create a new ASP.NET application, choose "MVC", and set authentication to "Individual User Accounts". In this example we are creating a new application for managing our own movie DVD collection, so we will name it MovieManager.


ASP.NET Two Factor Auth with Google's Authenticator App part 1

So you want to add two factor authentication to your site?

auth 1 screenshot

I have created a NuGet package that will get it running in 10 minutes. Alternatively, I have also written an article on how you can implement it manually without using the NuGet package.

This method is using ASP.NET’s Identity and Google’s “Authenticator” app. The authenticator app is simple, very widely used (GitHub and Slack, to name two) and works very well.

If you are adding two-factor authentication to an existing site or codebase, I would suggest that you start by creating a brand new project and adding the already-prepared NuGet package that I have prepared. This will ...

Fixing oWasps CSS

This week I heard about the .NET Security Cheat Sheet written by the owasp guys. So I opened it up on my mobile and saw this:

Eish. The text is tiny and you need to scroll around the screen to be able to read a sentence. Someone needs a mobile friendly CSS! So I tweeted them and got this response:

Fair enough.

So I fixed it... how's this?

The "main" culprit was the TABLE tag inside the HTML:

Removing that got us 50% of the way there... then we just needed a bit more CSS to clean it up:


Update for android app for East Timor

The last couple of months we have made some nice progress on our app. It's got a cool name, "Local Linguist", and it's had a facelift and a workover by some UI guys:

Each screen is much simplier and it will also include a section for listening to audio and providing a translation in your own language.

There's also a great interview with Katrina Langford, the "change maker" (eg, product owner) for the application. I could point out that so far we've won the Rhok Hackathon ahem *twice* but there's not a lot of point other than boasting, the value is in the results, not the kudos awarded on the way - though that definitely helps keep the motivation going, we're all human after all.

Plus here is a photo of the LocalLinguist team at the recent hackathon winning the trophy!! I'm not in the photo, I wasn't there on the day, but I've somewhat contributed to the project! But even still, great job guys.

While I'm here I might as well briefly mention that I recently gave a talk on "How to change things at your company" at DDD night, which was great fun. Here's a blurry photo of me doing my thing:


How I could have saved Carlo from HumanKode lots of money

You might have read the story how Carlo lost $6,500 thanks to a bug in Visual Studio GitHub's plugin.

It turns out that the issue was caused by a checkbox not working.

So what was the problem? The issue was that it's super-easy to accidently completely break a WPF control when you're just trying to change it's color. Why? Because if you want to change it, you have to completely override the entire control. So you end up having to copy and paste the code for the entire control, and then change what you need. So to fix the issue for Carlo they had to fetch the right control template code and then put it back in. But really, that's just a bandaid over a much, much more complicated problem.

I came across this problem in 2014 and suggested a (horrible) workaround. As you can see it's not simple, but it's better than nothing.


Async, await and ASP.NET

Today I came across a brilliant explanation of c#'s await keyword. I've been trying to figure it out for a couple of weeks now and every time I read it the explanation gets too complicated too quickly. The essential problem is as follows:

Marking a method as Async doesn't make it Asynchronous

And therein lies the confusion.

(BTW I'm not sure which genius came up with this. Probably the same person who came up with "Visual Studio Online" - because.. you know.. it's not actually an online version of visual studio.)

So anyway marking a method as async doesn't make it asynchronous. What the heck does it do?

Async releases the thread from the server pool

Huh? Well, normally each request in IIS takes up a thread. While IIS has a bewildering number of performance tuning options it essentially has a fixed number of threads available to process simultaneous requests. Each request uses a thread. So normally, the maximum number of simultaneous requests possible comes down to the maximum number of threads. So, if suddenly 1000 users hit your app at the same time, the 1001st user's request is going to be put into a queue, and they will have to wait. Now if your queue size is say 5000, and you then suddenly get 5000 more users h...