Unit testing your Silverlight/WP7 code with Portable Library Tools?

Thursday, 20 January 2011

I'm slowly improving my knowledge of developing in Silverlight and specifically apps for Windows Phone 7. My Internode Usage app has been out for almost a month, and I'm working on an update for that (including real Internode logos now that I've got permission). I've also been creating a new app that will display the nearest public toilet (particularly useful for parents of young kids, especially if you're travelling). That's been fun as I've got to use the Map control. I hope to publish that soon.

One thing I have missed was the ability to easily write unit tests for the code. The problem is that the code doesn't run on your desktop, it runs in the emulator or on a device. This has meant that most of the solutions so far have relied on running the test runner on the device as a separate application. That is certainly a valid way to test, but getting the results of the test back out isn't easy. Justin Angel describes one approach using the CoreCon API to read and write to the test app's Isolated Storage. Another way might be to get the test runner app to push the results back out to some kind of HTTP listener running externally to the emulator.

Enter the Portable Library Tools add-in. Just released as a CTP, this allows code to be targeted at both Windows Phone 7 and the regular CLR (as well as Silverlight and XNA) without having to jump through lots of hoops.

It should now be possible to create a regular .NET unit testing assembly (say using MbUnit with the Gallio test runner) and run tests over most of your code, and then just recompile to have the same code be deployed to WP7.

There will be exceptions, as you may need to refactor your code to extract out specific WP7 dependencies (that obviously have no equivalent in the desktop .NET Framework), but this looks like a promising step forward.

One caveat is that to install the Portable Library Tools, you need to have installed VS 2010 SP1 Beta. I'm being more careful about keeping my work laptop (which has also become my main dev machine) in good working order, so I'll be installing the SP1 beta on a separate VM just to be safe.

I'll do a follow-up post with my experiences. It might take a few days, as tomorrow I'm off riding in the Tour Down Under (again!), and might need a day or two to recover!

T-SQL int equivalents of decimal/numeric types

Monday, 17 January 2011

The DECIMAL type in T-SQL is for storing fixed precision numbers. You can define the total number of digits to store (the precision), as well as how many digits are to the right of the decimal point (the scale)

eg. to store a number in the range –9.9 to 9.9 (with 0.1 increments), you could use decimal(2, 1).

Sometimes database systems may store integer values using their equivalent of the decimal type (with a scale of zero), and when you use SSIS to import the data, it just defaults to creating a compatible schema.

There are some storage and potential performance benefits to using integer data types, so it may be worth checking whether the source data would actually fit inside a native int (or tinyint or bigint).

First, let's look at the storage requirements for decimal types. As you can see from Table 1, even a decimal(1,0) will still take up 5 bytes.

Table 1 - Bytes required to store decimal precision types
Decimal precision Storage bytes
1-9 5
10-19 9
20-28 13
29-38 17

Contrast this with the requirements for the integer types.

Table 2 - Bytes required to store integer types
Data type Range Storage bytes
tinyint 0 to 255 1
smallint -215 (-32,768) to 215-1 (32,767) 2
int -231 (-2,147,483,648) to 231-1 (2,147,483,647) 4
bigint -263 (-9,223,372,036,854,775,808) to 263-1 (9,223,372,036,854,775,807) 8

So for certain ranges of precision, the value can safely be stored in an equivalent integer type.

Table 3 - Compatible integer types
Decimal precision Integer equivalent Bytes saved
1-2 tinyint 4
3-4 smallint 3
5-9 int 1
10-18 bigint 1

If you do this, be very careful that you are not inviting overflow errors into your application.

Trial by Media Center

Monday, 10 January 2011

My Media Center has been misbehaving a bit lately, much to my (and the family's) annoyance.

First off, it the receiver started showing "tuner not available" errors. Restarting the machine would resolve the problem, but only temporarily. Installing the newer Hauppauge driver 7.9.1.28162 seems to have mostly fixed that (from the Hauppauge UK website). Along the way to resolving this, I also tried swapping the card into the other PCI Express slot, just in case that helped.

Then the Microsoft Remote stopped working. The display on the front of the Antec case said something like "bad command" for any button I pressed. Opening up the iMON software, I enabled sounds for invalid commands, and sure enough every button press resulted in the warning sound. Bizarre! The batteries in the controller were still fresh, so the only thing I could think of was to find the original IR receiver that came with the controller and plug that in. I'd never used it as the Antec case came with a receiver built in. In any case (ha ha), that seemed to resolve that one.

Then a few hours later, the sound spontaneously muted. Attempts to increase the volume worked briefly, then the volume would auotmatically wind back down to zero/mute. Alternatively, it rolled right up to 50 (100%). Rebooting and that one went away – not sure what's going on there.

So I'm keeping a close eye on things. Maybe the MCE is feeling jealous that the XBox 360 is getting some of it's screen time Smile

Internode Usage meter for Windows Phone 7

Tuesday, 28 December 2010

Screen grab of Internode Usage appMy first application for Windows Phone 7 has now been published to the marketplace!

It's a free usage meter for Internode's broadband customers. Want to check how your much quota you have left on your ADSL plan? This app will tell you.

The first version is pretty simple. It displays two sections. The first (shown above) displays your total quota, amount used so far, and the time the data was retrieved. The second section displays details for your account (see below).

To install it on your Windows Phone 7 device, go to http://social.zune.net/redirect?type=phoneApp&id=c9ebe665-de0d-e011-9264-00237de2db9e (Opens in Zune)


Overview

ScreenGrab-WelcomeWelcome screen

When you first run the app, a welcome screen is displayed and you are prompted to go to the settings page to enter your username and password. (In version 1.0, there's a bug where the big 'Settings' button doesn't do anything – you'll have to click on the settings icon Settings icon instead. This will be fixed in the next update)


ScreenGrab-Settings

Settings

Enter your Internode username (just the bit before the @ works for me)and password.

Click on the 'Save' icon to store these credentials.


ScreenGrab-DetailsDetails

Your account details, including full username, monthly quota, plan name and plan speed.

Coming next

Features I'm thinking of adding for the next update:

I'm also keen to hear of any other suggestions.

Acknowledgements

This application uses the Internode API, however for the canonical source for your usage, please always refer to My Internode.

In many ways, the app is inspired by Angus Johnson's Internode Monthly Usage Meter (MUM). I've been a happy MUM user for as long as I've had Internode ADSL.

Christmas 2010

Sunday, 26 December 2010

It's been a big Christmas season in the Gardiner family this year. Last week we dressed up as New Testament-era characters in Aberfoyle Uniting's re-creation of Bethlehem in "The Road to Christmas". Thursday evening Narelle and I joined some friends for carol singing at a local hospital, then Christmas Eve we attended church as a family. It was a good service, and included this thought-provoking modern-day take on what Mary and Joseph went through:
On Christmas day we were hosting immediate family at our place for lunch, and were then joined by some extra friends for tea. Narelle had a thought a few weeks back that to cater for this many people, a second fridge would be useful. After checking out some second-hand stores, I ended up bidding (and winning) one on eBay.
It has been a great fridge. It fitted all we needed to fit in it, and saved all those minutes of "angst" when trying to fit the leftovers in it after lunch and tea.
I must say that Narelle did an amazing job – the meat and vegies were perfectly cooked...and the pudding was out of this world.
(Narelle added the above two paragraphs while I was playing Kinect) But I agree, the fridge was a great idea.
The day started at not an unreasonable time. We'd been to Church the previous evening, so things weren't so rushed in the morning.
The XBox 360 + Kinect has proved a big success. Our family present this year, and all the family has been having a go - even our youngest (though sometimes to the frustration of other players!) – she can play some of the games, though some of the finer controls are too tricky for her yet.
We've had a lot of fun playing:
(Kinectimals and Kinect Joy Ride were presents, the other two titles came with the bundle).
So far I'm totally impressed. The only thing I could wish for would be some family-friendly titles to be published that can have more than two players at one time (I've heard Kinect can track up to 6 people, though I think you'd need lots of space for that).

Sesame Street: A Celebration of 40 Years of Life on the Street One of my other favourite presents had me up far later than I should have been Christmas night. I was only thinking the other day when we were watching "A Muppet Christmas Carol" that one of the best things to ever come out of the USA is Jim Henson's Muppets. That thought was reinforced by me getting a copy of Sesame Street: A Celebration of 40 Years of Life on the Street. A fascinating read so far.