21/09/2016

Report from the battlefield #6 - Auto-Property Initializers + a non-binary serialization

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Source: own resources, Authors: Agnieszka and Michał Komorowscy

I can bet that you've already heard about and used Auto-Property Initializers and that you love them. At least I do so ;) Here is a small example. In this case an Auto-Property Initializer was used to generate unique identifiers for instances of Entity class. Trivial, isn't it?
public class Entity
{
   public string Guid { get; } = System.Guid.NewGuid().ToString();
   /*...*/
}
What is important we have guaranteed that a given initializer will be executed only ONCE for an instance of a class. Otherwise it will have no sense! In other words our expectations is that if we create a new instance of Entity class it's identifier will not change. It is generally true, but there are some caveats.

16/09/2016

.NET Developer Days 2016 - Workshops

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In my previous post about .NET Developer Days 2016 I wrote generally about the conference and about presentations I'd like to see. This time I want to drop a few lines about pre-conference workshops (sessions). They will take place just a day before the actual conference (GoldenFloor, Millenium Plaza – Warsaw, Al. Jerozolimskie 123 a) and you could choose from:
The links above will lead you to the description of each session. However, I have a surprise for you. I contacted with experts who will conduct workshops and asked them a few questions. Here are additional information that I got. You'll not find them anywhere else.

31/08/2016

AjaxExtensions.BeginForm doesn't work. Really?

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Source: own resources, Authors: Agnieszka and Michał Komorowscy

The goal of using Ajax is to communicate with the server asynchronously without reloading the entire page. Specifically AjaxExtensions.BeginForm can be used to updated a selected part of a web page. It is relatively easy in use but can be also troublesome. Especially, when we try to apply it in an application which wasn't using Ajax earlier. I decided to wrote this short technical post because recently I came across the following issue the few times:

AjaxExtensions.BeginForm redirects a user to a new page instead of refreshing a fragment of a current one.

This problem has an easy explanation. Under the hood AjaxExtensions.BeginForm uses Java Script library called Microsoft jQuery Unobtrusive Ajax. The issue is that this library is not installed by default if we create a new project. It's easy to forget about it.

If you have the described problem:
  • Check in packages.config file contains Microsoft.jQuery.Unobtrusive.Ajax package.
  • Check if jquery.unobtrusive-ajax.js file is referenced in html e.g.: <script src="/scripts/jquery.unobtrusive-ajax.js"></script>
  • If you use bundles checik if jquery.unobtrusive-ajax.js was included in a bundle e.g.:
    public static void RegisterBundles(BundleCollection bundles)
    {
       ...
       var js = new ScriptBundle("~/bundles/MyBundle").Include("~/Scripts/jquery.unobtrusive-ajax.js");
       ...
    }
  • Besides, check if a bundle with jquery.unobtrusive-ajax.js is rendered properly e.g.:
    @Scripts.Render("~/bundles/MyBundle")

23/08/2016

.NET Developer Days 2016 are coming

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.NET Developer Days 2016 is a third edition of the biggest conference in Central and Eastern Europe dedicated to the .NET platform. I didn't participate in previous editions but this time I'll be. Why? Well, I read a few quite good reviews of a former editions. Besides, recently a friend of mine told me that he was going to go there what is also a good recomendation.

To make things funny, when I was about to buy tickets organizers of the conference asked me to write about it. So yes it is a sponsored text but I wouldn't write it if didn't want to go there anyway. Let's start with a few facts about .NET Developer Days 2016:
  • What: 3 tracks with 24 presentations.
  • Where: 
    • Conference: EXPO XXI Exhibition Center – Warsaw, Prądzyńskiego 12/14
    • Workshops: GoldenFloor, Millenium Plaza – Warsaw, Al. Jerozolimskie 123 a
  • When: 19th-21th October 2016. The workshops will take place on October 19th, and the conference will start one day later. Organizers also plan a party at the end of day one. I think that it'll be a good occasion for networking.
  • Language: 100% English
I'm still thinking which presentations to choose but I have a few solid candidates. I remember Jon Skeet from Dev Day conference. He gave a really good presentation so it is my number one. This time he will start the conference and then will talk about Abusing C# and Immutability. I also saw a few presentations delivered by Tomasz Kopacz in the past. As far as I remember he was always a mine of information. His presentations were advanced and demanding but you could learn a lot from them.

I also heard a lot of good about Maciej Aniserowicz so his presentation about CQRS is also on my list. I don't know other speakers but there are many other promising topics to choose from. For example, I'd like to listen Alex Mang who will talk about containers or Adam Granicz who will give a presentation about funcional programming or ... Actually, I already see some potenial conflicts in my personal agenda so as you can see the choice is not easy. I encorage you to see the full agenda on the conference site. If you want to buy a ticket do it sooner than later because the price goes up every 2 months.

See you there!

19/08/2016

My struggels with GitHub, Subtrees and Nuget

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Source: own resources, Authors: Agnieszka and Michał Komorowscy

Some time ago I decided to publish my projects on GitHub. This decision had very positive repercussion because it mobilized me to do more refactoring and to clean my solutions. Additionally, I switched totally to management of external references via NuGet. Earlier, I had some binaries in a dedicated directory on my computer. It took me some time but it was worth doing it.

I also had to solve the following problem. I have a solution called Common. It is a collection of libraries, utilities, algorithms, helpers etc. that are used in my other projects. Before migration to GitHub, after a build, all Common binaries were copied to the well known location i.e. N:\bin Thanks to that all other projects could reference them from this location. It works. However, if someone wants to download my projects from GitHub, he or she will need to create a mapped drive N manually. I din't like it.

The next step was to switch from absolute references to binaries to relative references to projects. For example let's consider a library MK.Utilities and a project LanguageTrainer that uses it. Initially LanguageTrainer was referencing:

N:\bin\MK.Utilities.dll

After migration this reference was changed to:

..\..\Common\MK.Utilities\MK.Utilities.csproj

Much more better, isn't it? Still, it is not perfect. This relative path will work only if the folder with Common and LanguageTrainer solutions will be in the same place on the disk. Besides, in order to compile LanguageTrainer solution Common solution must be built first. What's more Common and LanguageTrainer are two separate repositories which have to be downloaded individually. My goal was to be able to download any repository/solution and then be able to compile it without any further steps.

I started reading about possible solutions and I found information about git submodules and git subtrees. There is so much about them in Internet so I will not repeat others. For example see this post. At the end I decided to use subtrees. Simplifying a subtree is a copy of some repository in the another one. Returning to my earlier example, by using subtrees I got a copy of Common repository/solution in LanguageTrainer repository/solution. Then I could change the reference to MK.Utilities as follows:

..\Common\MK.Utilities\MK.Utilities.csproj

Besides, I needed to add MK.Utilities project to LanguageTrainer.sln solution so that all projects could be build at the same time. Finally, my LanguageTrainer repository/solution looks in the following way. On left side you can see GitHub and on the right side Visual Studio:


If needed I can refresh a copy of Common repository/solution inside LanguageTrainer at any time. Why I used subtrees? Well, they work for me and are extreamly easy to create via Source Tree ;) By the way, I like git but I hate all this complex commands. Source Tree solves this problem and allows me to use git via friendly GUI. I strongly recommend it.

At the end I had to solve one more problem with Nuget. Let's return again to my example and let's assume that LanguageTrainer solution is located here:

C:\LanguageTrainer

In that case, by default, Nuget packages will be located here:

C:\LanguageTrainer\packages

However, we also have a subtree:

C:\LanguageTrainer\Common

And projects from a subtree expects that their packages will be here:

C:\LanguageTrainer\Common\packages

Of course they won't be there so Common projects will not compile. To overcome this problem I had to manually update csproj files and replace ..\packages with $(Solutiondir)packages. For example:

..\packages\structuremap.3.1.6.186\lib\net40\StructureMap.dll

Was changed as follows:

$(SolutionDir)packages\structuremap.3.1.6.186\lib\net40\StructureMap.dll

I hope that this post will help you in your struggles with GitHub, Subtrees and Nuget.