MVC4 Conditional HTML Attributes

MVC4 made one simple and yet awesome improvement to View rendering that I don’t think many people are aware of. Have you ever had to conditionally add an attribute to an HTML element in your MVC View based on the presence of a variable? The typical use case is applying a CSS class to a div. Most of the time that code looks something like this: <div @(myClass == null ? [Read More]

Automatically Generate POCOs From DB With T4

The T4 template engine is insanely powerful. I didn’t really realize just how powerful it was until I had a use case for it today. I stood up a database with about 40 tables in it, and planned to use an ORM to access the database. To use the ORM, I needed POCOs (Plain Old C# Objects) that represented my database. Some of these tables had 30-50 or so columns and I didn’t want to code all of this by hand – it would take literally days. [Read More]

Web API Mapping QueryString/Form Input

If you’re using the Web API as part of the MVC4 framework, you may encounter a scenario in which you must map parameters of strange names to variables for which characters of the name would be illegal. That wasn’t very clear, so let’s do this by example. Consider part of the Facebook API: Firstly, Facebook servers will make a single HTTP GET to your callback URL when you try to add or modify a subscription. [Read More]

Generic Comparer

Have you ever had to write a comparer for a specific type, only to be frustrated when you needed to write a second and third comparer for other types? Fear not, a generic comparer can take care of this for you! /// <summary> /// Compares two objects of any type. /// </summary> /// <typeparam name="T">The type to be compared.</typeparam> public class GenericComparer<T> : IComparer<T> { // The compare method private readonly Func<T, T, int> _compareMethod = null; /// <summary> /// The constructor. [Read More]

Make Mostly Read, Seldom-Written Lists Much More Efficient

One of the many things that I do at work is run a full-blown Search Engine which I also developed from scratch. This Search Engine feeds all product related information to our websites. A search index consists of a pre-computed collection of products, their properties, a list of words that are correctly spelled, and some pre-computed faceted/guided navigation. A search index, until this week, took up approximately 10.7 gigs of memory. [Read More]

A Better MIME Mapping Stealer!

In the interest of self-improvement and sharing knowledge, I felt that I should share an update to my last post. I discovered a slightly better way to create the GetMimeMapping delegate/method via reflection that involves less casting and overhead, and is more Object Oriented in a sense. It allows the signature of the reflected method to be Func<string, string> instead of MethodInfo. Code below, note the use of Delegate.CreateDelegate(Type, MethodInfo): [Read More]

Determine MIME Type from File Name

I recently had a need, in an ASP.NET MVC3 application, to read raw HTML, CSS, JS, and image files from disk and return them to the user… A sort of “pass-through” if you will. Normally I’d have simply routed to a custom HTTP handler per file type or just allowed MVC3 to map existing files to supply its own .NET HTTP handlers and do all of this work for me, but in this case I needed the mapped “directory” to switch behind the scenes based on Session settings… So I ultimately had to feed these files through a Controller and Action Method to gain access to the Session. [Read More]

Published by Red Gate

As of today I’ve been published in an e-Book offered for free by Red Gate! It is called 50 Ways to Avoid, Find and Fix ASP.NET Performance Issues and contains many useful performance tips which have been contributed by various members of the .NET community. Many tips are ASP.NET MVC specific which is also a plus. My tip is #3 and has to do with debugging Microsoft symbols. Get a free copy here – it has already taught me a few things I had never thought to consider! [Read More]

But it Didn't Happen in DEV or QA!

Most of us have been there: you’ve written a fantastic application that performs perfectly in your Development and/or QA environments, but in Production something goes wrong. Your application spins out of control, utilizing 100% of your CPU. Maybe it simply stops responding as if it were deadlocked. Or maybe it simply crashes randomly. What now? Logic tells you that you have a problem in the code somewhere that is only encountered in a Production-like environment… and if you could JUST get into the Production box, install Visual Studio (or at least the Remote Debugger), and debug the application, you’d be able to solve the problem. [Read More]