Patrick Steele's .NET Blog

Updates to Nino’s .hgignore files for Visual Studio

As I move more of my repositories from SVN to Mercurial, I’m constantly referring to Nino’s sample .hgignore file he provided for Visual Studio developers.  I always start with his file but add a few more lines and thought I’d share them here.  Start with Nino’s .hgignore file and add the following two lines at the bottom:

TestResults\*
glob:desktop.ini

Obviously, we don’t need to version our TestResults.  And I don’t want to version the occasional desktop.ini that gets generated by XP when you tweak folder settings.

Verbosity Isn’t Always a Bad Thing

There was a message posted to the Rhino.Mocks forums yesterday about verifying a single parameter of a method that accepted 5 parameters.  The code looked like this:

[TestMethod]

public void ShouldCallTheAvanceServiceWithTheAValidGuid()

{

    _sut.Send(_sampleInput);

    _avanceInterface.AssertWasCalled(x => x.SendData(

        Arg<Guid>.Is.Equal(Guid.Empty),

        Arg<string>.Is.Anything,

        Arg<string>.Is.Anything,

        Arg<string>.Is.Anything,

        Arg<string>.Is.Anything));

}

Not the prettiest code, but it does work.

I was going to reply that he could use the “GetArgumentsForCallsMadeOn” method to pull out an array that would contain all of the arguments.  A quick check of “args[0]” would be all that he needed.  But then Tim Barcz replied with the following:

Just to help allay your fears a bit...this verbosity isn't always a bad thing.  When I read the code, based on the syntax you have used I know that for this particular test no parameters matter except the first...extremely useful in my opinion.

An excellent point!  We need to make sure our unit tests are as clear as our code.

Backing Up with FTP

I finally set aside some time to upgrade to Windows 7.  Most everyone else in the office has already upgraded.  I was holding out so I could finish up a few client projects and get the Ann Arbor GiveCamp website up and running.  Now it’s my turn!

A Clean Install

A few people told me NOT to do an upgrade install of Windows 7.  Instead, do a clean install by formatting your hard drive.  Obviously, you’ll want to make sure everything is backed up before doing this.  At home, I have a FreeNAS server that does daily backups via rsync (thanks to DeltaCopy).  However, I wasn’t quite backing up everything so I had a little extra work to do.  Actually, I found quite a bit of important stuff that wasn’t on my daily schedule.

I originally was using Windows Explorer to copy/paste directories.  However, when you’ve got a lot of copying to do, it’s not very efficient.  Small hiccups along the way usually halt the entire operation and you have to start over.  I decided I’d just use FileZilla and FTP everything over to my NAS server (since it can be an FTP server as well).  I can place a whole ton of files in a queue, control the queue processing and easily retry failed transfers.  This type of control reduced my backup time immensely.

File Transfer Mode

The one problem with using FTP to backup files is that FTP has two different transfer modes: Binary and ASCII.  When moving files between a windows and unix-based system (as I was since FreeNAS is based on FreeBSD), ASCII/text files are converted so the CR/LF from windows gets converted just to a CR in unix.  Most FTP clients (including Mozilla) have an “auto-detect” mode and pick the appropriate mode to use based on the file type.  They always transfer things like .txt and .xml files as ASCII and other files like .png, .bmp or .mp3 as binary and everything just works.

But there are exceptions!  After moving some of my files back to my Win7 machine (using FileZilla in the opposite direction), I noticed that my Mercurial repositories were showing up as having changes (I committed everything before re-paving my machine).  And one repository was reporting a corrupt index.  Ugh…  As I started poking around inside the Mercurial data storage files, I started to think that perhaps some of these were transferred as ASCII when they actually should have been binary!

Once I realized what had happened, I felt pretty stupid.  Since I was using FTP solely as a backup tool (and not really to “transfer” a file for use on the other machine), I should have forced FileZilla to use binary transfer so everything would have been an exact copy, byte for byte.  I did a quick test of a Mercurial repository and transferred it in both “auto” mode as well as “binary” mode.  Of course, binary mode went back and forth without a hitch.

Fixing My Repositories

This isn’t FileZilla’s fault.  If I figured out exactly what caused the file corruption (and in what file), I probably could have just configured FileZilla to transfer those specific file types as binary.  Luckily, the repositories that showed some corruption were small, private repositories that only I used.  And the Mercurial wiki had a page that showed me how to fix the problem.  I ended up using the “Recovery using Convert extension” option.  It fixed my repositories and I didn’t loose any changesets.  Nice!

Tweaking log4net Settings Programmatically

A few months ago, I had to dynamically add a log4net appender at runtime.  Now I find myself in another log4net situation.  I need to modify the configuration of my appenders at runtime.

My client requires all files generated by our applications to be saved to a specific location.  This location is determined at runtime.  Therefore, I want my FileAppenders to log their data to this specific location – but I won't know the location until runtime so I can't add it to the XML configuration file I'm using.

No problem.  Bing is my new friend and returned a couple of hits.  I made a few tweaks to their LINQ queries and created a generic extension method for ILoggerRepository (just a hunch that I might want this functionality somewhere else in the future – sorry YAGNI fans):

public static void ModifyAppenders<T>(this ILoggerRepository repository, Action<T> modify) where T:log4net.Appender.AppenderSkeleton

{

    var appenders = from appender in log4net.LogManager.GetRepository().GetAppenders()

                        where appender is T

                        select appender as T;

    foreach (var appender in appenders)

    {

        modify(appender);

        appender.ActivateOptions();

    }

}

Now I can easily add the proper directory prefix to all of my FileAppenders at runtime:

log4net.LogManager.GetRepository().ModifyAppenders<FileAppender>(a =>

                {

                    a.File = Path.Combine(settings.ConfigDirectory,

                                          Path.GetFileName(a.File));

                });

Ann Arbor Day of .NET 2010 Recap

Had a great time at the Ann Arbor Day of .NET on Saturday.  Lots of great speakers and topics.  And chance to meet up with friends you usually only communicate with via email/twitter.

My Presentation

I presented "Getting up to speed with C# 3.5 — Just in time for 4.0!".  There's still a lot of devs that are either stuck in .NET 2.0 or just now moving to .NET 3.5.  This presentation gave highlights of a lot of the key features of 3.5.  I had great questions from the audience.  Afterwards, I talked with a few people who are just now getting in to 3.5 and they told me they had a lot of "A HA!" moments when something I said finally clicked and made sense from a code sample they had seen on the web.  Thanks to all who attended!

A few people have asked me for the slides and demo.  The slides were nothing more than a table of contents.  90% of the presentation was spent inside Visual Studio demo'ing new techniques.  However, I have included it in the ZIP file with the sample solution.  You can download it here.

Dennis Burton on MongoDB

I caught Dennis Burton's presentation on MongoDB.  I was really interested in this one as I've missed the last few times Dennis had given it to local user groups.  It was very informative and I want to spend some time learning more about MongoDB.  I'm still an old-school relational guy, but I'm willing to investigate alternatives.

Brian Genisio on Prism

Since I'm not a Silverlight/WPF guy (yet), I wasn't sure this would interest me.  But I talked with Brian for a couple of minutes before the presentation and he convinced me to catch it.  And I'm glad he did.  Prism looks like a very nice framework for "composable UI's" in Silverlight and WPF.  I like the whole "dependency injection" feel to it.  Nice job Brian!

GiveCamp Planning

I spent some time Saturday working on things for the upcoming GiveCamp (which is why I only caught a few sessions).  Ann Arbor's Day of .NET and GiveCamp have both been held at Washtenaw Community College so I took some time (along with fellow GiveCamp planners Mike Eaton and John Hopkins) to check out the new location for Ann Arbor GiveCamp this year!

In the past, WCC has let us use the Business Education (BE) building for our GiveCamp's.  But this year, they're moving us over to the Morris Lawrence (ML) building.  Let me tell you – this is a step UP!  In the BE building, we were spread across two floors and spread out into classrooms.  Plus, our opening and closing ceremonies were held in the Liberal Arts (LA) building – a bit of a walk from the BE building.

In the ML building, we're together for the whole weekend.  We've got a large open area (which can be sectioned off if needed) for everyone to work in:

Right next to that, we have a large area where we can set up tables and eat.  And it helps that we have a wonderful view while eating (yes, that's a lake out there with a fountain):

The ML building also has showers (which we'll have access to!) and it's own auditorium for our opening and closing ceremonies.

All in all, this year's GiveCamp will be great! Stay tuned to the Ann Arbor GiveCamp website.  We'll be looking for volunteers (devs, designers, PM's, etc…) soon!