I was doing something quite innocent the other day: I was trying to provide authentication on top of the .NET 4.0 WCF Data Services (DS) on a per method basis, e.g. let folks read all they want but stop them from writing unless they’re an authorized user. In the absence of an authorized user, I threw a DataServicesException with a 401 and the right header set to stop execution of my server-side method and communicate to the client that it should ask for a login.

In addition, on the DS client, also written in .NET 4.0, I was attempting to use batch mode to reduce the number of round trips between the client and the server.

I can’t imagine anyone reading this blog needs to read this, but I can’t help myself.

When I was just a wee lad, probably the most valuable thing I learned was how to perform mathematical estimation, the importance of which and several techniques you can get by reading Jon Bentley’s The Back of the Envelope (this essay along with several others, are collected in his most excellent books Programming Pearls and More Programming Pearls, both of which are still relevant a decade later). Not only is estimation generally quicker than running a calculator, but even when you do run a calculator, it helps you figure out when you did it wrong, the latter of which has saved my bacon time and again.

Years ago, when I was on my T-Mobile Dash, I would purchase a new phone every quarter or so, just to see if something better had come along. Always, within a week or so, I returned it and went happily back to my T-Mobile Dash. Then came the iPhone, which I instantly fell in love with. I didn’t think I’d ever give it up. Then came the Samsung Focus, one of the first Windows Phone 7 phones and I haven’t turned my iPhone 4 back on since. It’s not all I’d hoped for, but it’s damn close!

Meeting Expectations

I’m fond of quoting my father to my sons. I have a terrible memory for these kinds of things in general, but what he says sticks with me:

• “Anything worth doing is worth doing right.” –Mike Sells
• “Don’t start a fight, but be ready to finish one.” –Mike Sells
• “Who got the goddamn jelly in the goddamn peanut butter?!” –Mike Sells

I’ve been playing around with JavaScript a great deal lately and trying to find my way. I last programmed JS seriously about 10 years ago and it’s amazing to me how much the world has changed since then. For example, the fifth edition of ECMAScript (ES5) has recently been approved for standardization and it’s already widely implemented in modern browsers, including my favorite browser, IE9.

Fluent LINQ

I use LINQPad all the time for a bunch of stuff, but most recently and most relevant, I’ve been using it for a personal chore that isn’t developer-related: I’ve been using it to do budgeting.

What is LINQPad?

“If you want to build a ship, don’t drum up people to gather wood, divide the work, and give them orders. Instead, teach them to yearn for the vast and endless sea.”

Antoine De Saint-Exupery, author of “The Little Prince”

In the old days, the post-colonial, pre-LINQ days of yore, I’d have written a one-way MD5 encryption like so:

static string GetMD5String(string s) {
  MD5 md5 = new MD5CryptoServiceProvider();
  byte[] hash = md5.ComputeHash(Encoding.ASCII.GetBytes(s));
  StringBuilder sb = new StringBuilder();
  foreach( byte b in hash ) sb.AppendFormat("{0:x2}", b);
  return sb.ToString();
}