James Crisp

Optus, my ISP, is kind enough to give subscribers a free copy of F-Secure’s security suite which offers anti-virus, anti-spam and firewall. I read some half decent reviews of the product so I thought I’d install it and give it a go. Unfortunately, it was fraught with problems. First of all, after installing I got a blue screen on reboots. After uninstalling AVG (my previous anti-virus) in safe mode, my computer could boot. Next, I tried to do a full system scan, but the F-Secure automatic update kicked in at the same time and it crashed the scanner. So, I rebooted, and tried a full system scan. I tried twice, but each time, it hung on a random .class (compiled Java) from GlassFish. Not great. So I went to the F-Secure website to submit a bug report. I filled in the form, and couldn’t submit it because one of the drop down lists which was mandatory was disabled in Opera. I then thought I’d try the site in IE7, but IE7 just hung, presumably thanks to F-Secure’s firewall.

Overall, I would strongly suggest that you do not bother to try the F-Secure product suite, even if it is offered to you for free.

Just finished reading “The Long Tail - How Endless Choice is Creating Unlimited Demand” by Chris Anderson. In summary, the long tail is about selling small volumes of a vast variety of items instead of large volumes of a small number of “hits”. This possible when the cost of distribution to geographically distant customers is low and the cost of storage for stock is not a concern (eg, intellectual property in electronic format, JIT manufacture). Popular companies capitalising on the long tail include eBay, Amazon, Google Adwords and Lulu.

The book has a lot of interesting stories and statistics but tends to repeat itself often. The long tail idea is probably not new to most readers these days, and I think if you’re familiar with Amazon, there’s little that comes as a surprise. However, I did find an interesting section in the book about the tyranny of choice. Anderson suggests that choice is good, customers want choice, and choice is only a problem if you don’t know what to choose to suit your taste. Hence, an important part of a long tail business is helping people find what they want (ie, filter out noise) in all the vast array of choices. He suggests using user reviews, rankings, sorting etc as means to help people find the “best” choice for them. I also hadn’t come across Lulu before - looks worth checking out, a site for mini self-publishing.

In .NET 2, it was all the rage to make hand-crafted, clever IDisposables that let you do a bounded action with clean up. Eg,

void SomeMethod()
{
        using (new SetCursorToWaitEggTimer())
        {
            VerySlowOperation();
        }
}

void VerySlowOperation()
{
    ... etc ...
}

This was kind of cute - you could make sure that, even if an exception was thrown, your clean up (eg, changing cursor back to normal) would occur. Implementing the IDisposable was a bit ugly but consuming it wasn’t bad.

Now, with the sexy C# 3 syntax, you can do something similar much more elegantly. Eg,

void SomeMethod()
{
       DoWithWaitEggTimer(VerySlowOperation);
}

void DoWithWaitEggTimer(Action action)
{
    try
    {
        Mouse.OverrideCursor = Cursors.Wait;
        action();
    }
    finally
    {
        Mouse.OverrideCursor = null;
    }
}

If you’re feeling like more adventures, you can also start passing these delegates around and injecting them. For example:

class SomeClass
{
    public Action RunSlowCode
    {
    	get { return runSlowCode ?? new Action(a => a.Invoke()); }
    	set { runSlowCode = value; }
    }
    Action runSlowCode;

    void DoSomethingSlow()
    {
         RunSlowCode(PullDataFromExternalSystem);
    }
}

This approach allows you to inject the delegate for what happens when slow code is run. So you could inject DoWithWaitEggTimer() or something new like DoWithWaitMessageDisplayedToUser(). Similarly, it could be used for unit testing or injecting between layers in your application.

The default access modifier for the members of a C# class (eg, fields, methods, and properties) is ‘private’. As such, I recommend never using the redundant ‘private’ keyword for class members. Leaving off the private nicely separates your privates from your public/inheritable interface in syntax highlighting. It also saves people having to read redundant code - you wouldn’t want your code to be full of un-needed casts, or redundant ‘this.’ references, would you?

Working in WPF is quite exciting - there’s a lot of new possibilities, especially with easy control composition, much improved binding and Expression Blend to make sexy interfaces. One of the things you’re likely to want to do though, when writing anything more than a toy application, is to have a base class for your UserControls or Windows, to share common functionality. It is also quite likely you will want to use generics in conjunction with control inheritance. With both the code behind, and the XAML, it’s not immediately obvious how to do generic inheritance. It is a bit fiddly to get going, and sometimes the errors are not helpful. Here’s a simple example that outlines how to bring it together.

The base control

namespace WpfGenericsDemo
{
    public class BaseUserControl<T> : UserControl where T : IPresenter
    {
        public BaseUserControl()
        {
            ... various configurations ...
        }

         ... Awesome functionality to share ...
    }
}

The child control code-behind

namespace WpfGenericsDemo
{
    public partial class ChildUserControl : BaseUserControl<ChildPresenter>
    {
        public ChildUserControl()
        {
            InitializeComponent();
        }

         ... More code ...
    }
}

The child control XAML

<WpfGenericsDemo:BaseUserControl x:Class="WpfGenericsDemo.ChildUserControl"
    x:TypeArguments="WpfGenericsDemo:ChildPresenter"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    xmlns:WpfGenericsDemo="clr-namespace:WpfGenericsDemo">

    ... The rest of your awesome XAML ...

</WpfGenericsDemo:BaseUserControl>

Notes

• Your top level node is the parent class of the control you want to create (eg, BaseUserControl). You specify the control class you want to create with ‘x:class’ (eg, ChildUserControl)
• ‘x:TypeArguments’ is the way you specify the generic type (eg, ChildPresenter)
• You need to namespace your classes - eg, with ‘xmlns:WpfGenericsDemo’ which uses a clr-namespace style reference
• Only your top level node can be genericised in XAML

Recently, I’ve been disappointed to find my Treo 650 turning off the phone radio by itself. If I was lucky, I heard the melodic sound that means “radio now off”, and then I manually turned the radio back on. If I was unlucky, I didn’t hear it, and missed phone calls and messages.

It seems that the cause is that the Treo 650 SIM case gets looser with wear, and any break in connection between the SIM and the phone causes the phone radio to be deactivated. The solution is pretty easy, and described at the end of a FAQ I came across. In summary, take out the SIM tray from the phone, remove the SIM. Put several layers of paper (cut small to fit) in the SIM tray, and then clip the SIM back on top. When you put the SIM tray back into your phone, it should work reliably again, with no more random turn-offs!

Wondering if your loan repayment calculations have been performed correctly this month, taking into account interest rate rises and extra repayments? You might be interested in giving my monthly loan calculator a go.

As my home loan provider doesn’t show balances online, and only sends statements every 6 months, I like to ring up every month or two to make sure things are on track. I used to calculate interest, new balances etc in a spreadsheet / calculator but spent an afternoon writing a little Rails app to calculate it for me. Hopefully my little monthly loan calculator is of some use to you too.

NUnit tests can be run using a variety of different runners. Some common ones are:

• NUnit GUI
• Test Driven .NET
• Resharper test runner
• NUnit MS Build Task

The NUnit GUI and Test Driven create a new instance of the test class for each test run. This leads to more isolation but potentially slower performance.

Resharper and NUnit MSBuild Task re-use the same instance of the test class when running each test in the class. This can lead to unintended interaction between tests. Using these runners, it is vital to to assign initial values to instance variables in SetUp, rather than when they are defined or in the constructor.

If you use a mix of different test runners, you can end up with tests that pass on some machines and fail on others (eg, Test Driven locally works fine, but you use NUnit MSBuild Task on your build box and get intermittent failures).

If you have a ChildTestCase class that inherits from a ParentTestCase class, and both of these have a SetUp method, marked with the [SetUp] attribute, would you expect both to be called? If so, you would be sadly disappointed. Only the SetUp method of the ChildTestCase will be called, and the SetUp in the ParentTestCase will be ignored.

According to the NUnit documentation on the Set Up attribute, this is intended behaviour:

If you wish to add more SetUp functionality in a derived class you need to mark the method with the appropriate attribute and then call the base class method.

An alternative approach to get all your SetUps called is to have a base TestCase class define a protected virtual SetUp() (with the SetUp attribute), which all child classes override (and call base on their first line).

Sybase has some unusual features:

• Column names and table names are case sensitive
• Subqueries cannot include TOP 1 or ORDER BY
• Queries with max(COLUMN_NAME) and an ORDER BY seem to ignore the WHERE clause. Removing ORDER BY seems to fix this.
• Column names are 30 characters max
• Join syntax is: left_table [inner | left [outer] | right [outer]] join right_table on left_column_name = right_column_name
• Can’t do boolean operations in SELECT (eg, =, > <), but can do mathematical operations (eg, +, -) in SELECT clause

Just finished reading “Process Consulting” by Alan Weiss, lent to me by my talented colleague, Darren Smith. The book is concerned more with general consulting, not IT consulting or IT methodologies. I found the bigger picture view in Weiss’s book enlightening and helpful in evaluating and questioning my own consulting practices. Here’s a few thoughts from the book:

• Remember that you are not the change agent. The client personnel are the change agents. You are the catalyst, but they are accountable for enduring change. Don’t be a hero…
• Cute phrases and pithy slogans don’t change behaviour. Aligning people’s objectives behind corporate objectives and supporting that behaviour with metrics and rewards will usually gain their attention. Rapidly.
• Is it really progress if we teach a cannibal to use a knife and fork? (from Stanislaw Lem, quoted by Weiss)
• At the outset of any change process, immediately after agreement with the buyer, identify and “recruit” these key positions [hierarchical leaders, front line management, respected leaders and experts]. Use the buyer’s clout if you must. The most crucial factor in organizational change occurs prior to implementation: It’s the conceptual agreement and acknowledged self-interest among the few people who actually have their hands on the controls.
• [Regarding change,] neutral is as bad as negative, since the default position for everyone else will always be the old behaviour.
• Don’t be anxious to “make change”. If you have a six month window, for example, invest at least the first month or more aligning your support and key sponsors and establishing their accountabilities. The more time you take with critical sponsors, the faster you will ultimately create change.
• When you find someone micromanaging, it is almost always because of a lack of trust. If you don’t do the job the way he or she would do it, you must be doing it incorrectly. If the leader has trust in subordinates, simply providing the goals should be sufficient.

BarCamp Sydney is two days long this year, and will span the whole of the coming weekend (5-6 April). I’ll be there on Saturday. It’s usually quite a fun event, lots of good sessions and you’re quite free to move around and find something that interests you. Part of the BarCamp manifesto is that you should also contribute as well as listen - I’ll probably give a JRuby talk and demo.

Hope to see you at BarCamp!

Here’s the slides from “JRuby: Enterprise 2.0″ from our recent talks at Sun Tech Day and the ACS Web Technologies SIG.

Josh Price and I will be co-presenting at the Melbourne Sun Tech Day and the Sydney ACS Web Technologies SIG. Here’s the low down:

Hope to see you there!

The fine folk at Apress sent me a copy of Ola Bini’s new book to review. The full title is “Practical JRuby on Rails Web 2.0 Projects - Bringing Ruby On Rails to the Java Platform”. Overall, it was a good read, and extremely valuable to anyone who is developing in JRuby. JRuby information and documentation is scarce and most of the time, a Google trawl does not give you good results on a JRuby related query. Ola’s is the first, and currently the only JRuby book available, and in my experience, the most valuable resource available to give you an all-round picture of JRuby capabilities and usage.

Audience
Despite comments on the cover, I would suggest that this book is not ideal for people new to Ruby / Rails. Ola jumps in the deep end quite quickly, and being a talented Ruby programmer, makes use of lots of shorthand, procs, code blocks etc which would likely be hard to follow for someone new to Ruby. Although there is a section at the back called “Ruby for Java programmers”, I think this would not be sufficient for somebody new to Ruby to understand all the code examples.

To get the most value out of the book, it would be good to have at least a basic understanding of Ruby and Rails (eg, having read Agile Web Development with Rails or messed around with Ruby/Rails a bit) and a basic understanding of Java syntax, deployment and Java EE.

What’s Covered?
The book is project based, so as to give context and useful examples of JRuby functionality. There are 4 projects:

• The Store (Shoplet) - a standard Rails app running under JRuby using Active Record JDBC.
• Content management system - general Java integration and using Java libraries for content rendering.
• Administration System - using EJBs, JMX and discussion of JRuby deployment options.
• Library System - JRuby as the “glue that never sets”. Using Java Web service frameworks and JMS from JRuby.

The Good

• Teaches you how to do all those tricky bits which are half-Java and half-Ruby and can’t be easily found online, such as converting between Ruby and Java types, including JAR files, implementing Java interfaces, etc
• Clever and concise Ruby code - I picked up some Ruby tricks reading Ola’s code.
• Complex code snippets are generally well explained in text.
• Useful tips on when to use Java libraries and when to use Ruby ones.
• Generally good and interesting example projects which justified the use of JRuby and the techniques shown in the book.
• Helpful discussion of JDBC and database connectivity options for JRuby.
• Nice overview of the many JRuby deployment options.
• Helpful “sidebars” about Java Enterprise Edition technologies.
• Covers the strong areas of JRuby well - web applications and system integration.
• Appendices provide useful reference information.
• Nice section at the end on how you can get involved in JRuby.

The Less Good

• Example views often contain table layouts, inline styles and other layout information that would be better done in separate CSS files.
• Variable names in code could be more descriptive. This would make example code easier to follow.
• Occasional odd spelling like “sur_name” and use of deprecated Rails features, such as “start_form_tag” (to be fair though, Rails API does change very quickly).
• The title suggests that the book is about Web 2.0. There is a little token AJAX, and I suppose a content management system is a bit Web 2.0, but overall, buy the book if you want to know about JRuby, not Web 2.0.
• Although REST is only mentioned briefly in a little sidebar, and not a focus of the book, I found the description of REST and CRUD a bit misleading, especially when considering PUT vs POST.
• The discussion of JRuby deployment provides a good overview, but more in depth discussion of major options (eg, GoldSpike), and production configurations would be great.

Conclusion
As the best and only JRuby reference, I’d highly recommend you buy a copy if you are working in, or planning to work in JRuby. The book will help you to write JRuby applications which make good use of Ruby, Rails, Java libraries and Java Enterprise Edition features.