Designing a Short Course on IoC: Day 2
So, yesterday, a lot of thinking. Today it’s time to start fleshing out some of the things we’ll need.
The course is going to be split into four sections, to match the natural division of the day by morning tea, lunch and afternoon tea:
Resources and Units of Work
Containers and Tooling
Session 1: Fundamentals
First up, we’ll set the theme of the day with some collaborative development. To introduce the vocabulary and concepts of IoC, we’ll write a simple IoC container in C# and integrate it into an ASP.NET MVC application. There are plenty of interesting design issues along the way that we’ll come back to in our discussion of containers and tooling.
Session 2: Effective IoC
The second session will introduce a ‘real’ IoC container. The focus will be on techniques and features that allow IoC to support large, complex applications in the real world. We’ll touch on all of the typical components of MVC web applications as we migrate from the simple container we built ourselves, but we’ll pay special attention to the integration between IoC and domain models because of the challenges and opportunities they present.
Session 3: Resources and Units of Work
Lifetime, AKA “resource management” can be the toughest aspect of IoC to master. We’ll take an excursion outside of the comfort of the web tier, to develop a thorough understanding of the issues involved and their solutions.
Although it is far from being ready for prime time, Whitebox will be a great way to explore the runtime behaviour of lifetime scenarios, so sometime over the coming week I’ll look at filling remaining gaps there.
Session 4: Containers and Tooling
To round out the day, we’ll use the last session to take a leisurely tour of the sights, sounds and smells of the .NET IoC ecosystem. Choosing an IoC container can be tricky business, especially when the easiest metrics to grasp, for example throughput performance, are often misleading or irrelevant. In addition to looking at some of the popular offerings and their relative strengths, I think this is where a discussion of MEF and its role will fit in nicely.
Session 4 will also give us an opportunity to examine debugging and diagnostics issues.
So, what do you think?
Today’s focus for me will be to take a first cut at building the example application. I’m going to leave the ‘simple container’ design task for the event, so that we can truly do it on the fly! I want the day to be heavy on code and light on slides, so dressing up a slide deck with some guiding material will wait for later in the week.
Choosing what kind of application to build is tricky. I want attendees to be able to take something away, ideally a sample that isn’t too far from production readiness. In that respect, simpler will be better, though it can be hard to get enough breadth out of something like a ‘to-do’ or ‘timesheeting’ application. There’s some high-quality code on the web that might be reused for this purpose (e.g. FunnelWeb) so building something that mimics an existing open source application has advantages.
I’ll update you tomorrow on where things land.