The danger of frameworks

I introduced Entity Framework (Code first) to my team in the beginning of this week. The other devs have not used it before, but as they are a Microsoft focused shop it was the only option other than ADO.NET. EF is a great tool but yet again I’ve got an example of how it blinds developers. It’s not just a Entity Framework problem, but frameworks in general.

The thing is that we have tables which represents our entities. Some of the tables are loosely coupled, but the EF Power Tools interpreted the relations as strong (thus interpreting some tables as junction tables). Most of the problems was sorted quickly by the dev. But one problem remained. And that was that cascading deletes did not work.

Instead of writing the delete queries manually the dev spent a day or two to fix the problem. I’m quite certain that a vanilla ADO.NET solution would have taken at most 30 minutes. What I’m saying is that ORMs works for most cases but not all. Unfortunately they blind developers. ORMs are so easy to use for the more common cases that the devs doesn’t seem to see that they waste hours on something that could have taken minutes with an alternative solution.

Use the right tool for the job.

Introducing the data mapper in Griffin.Framework

As you might know I’m running a .NET exception service called OneTrueError. When I moved from a NoSQL db to SQL Azure I had to be able to work with the database in some way. I’m not using OR/Ms any more. They might significantly reduce the bootstrapping, but in the long run they always tend to make you struggle as the application grow. To me, ORMs is a bit like ASP.NET WebForms, but for data. i.e. it tries to make something what it isn’t. I therefore wanted something that did not take away the control from me nor hide the underlying layer. I still want to work with my domain entities though.

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OneTrueError and the WinForms/WPF integration

OneTrueError is a new startup which also is a member of Microsoft BizSpark. This post is about the client library for WinForms/WPF. It will catch and handle all uncaught exceptions automatically. The errors are also uploaded to our site for analysis to enable us to suggest possible solutions

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Alternative to IEnumerable for read-only collections

.NET 4.5 introduced a new interface which is great if you want to expose a collection as readonly.

The problem with IEnumerable<T> is that it’s forward only. i.e. there is no guarantee that you can traverse it multiple times. The collection size might also be unknown, depending on the implementation.

So if you want to expose a collection which can be traversed multiple times and where the size is know there is as of .NET 4.5 another alternative. And that’s IReadOnlyList<T>. It inherits another new interface called IReadOnlyCollection<out T>.

Code

public interface IReadOnlyCollection<out T> 
      : IEnumerable<T>, 
        IEnumerable
{
    int Count { get; }
}

public interface IReadOnlyList<out T> 
      : IReadOnlyCollection<T>
      , IEnumerable<T>
      , IEnumerable
{
    T this[int index] { get; }
}

Usage example

public class MyRepository
{
    public IReadOnlyList<User> FindUsers(string lastName)
    {
        // [...]
    }

    // [...]
}

Immutable collections should not implement mutable interfaces

I just read the new blog post about .NETs new mutable collections. It mostly looks really nice, but there is a major problem: They implement mutable interfaces like IList<T> which has an Add() method.

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Azure failed me

(this entry was previously published as a PDF on twitter since I couldn’t access my blog)
I really liked my first experience with Azure. I’m also going to certify myself (I still am). But that’s before things stopped working and I got some not very good support. This blog entry is awas a PDF because I currently can’tcan use my blog. This entry is all about why.

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