Codeharder

Creating a custom configuration section can be done in 3 easy steps. However, accessing section with a ConfigurationElementCollection can be tedious. Let me explain.

Let’s pretend you have a section that looks like this:

<namedUrlSection favoriteUrl="CodeHarder">
  <namedUrls>
    <add name="Twitter" url="http://twitter.com"/>
    <add name="CodeHarder" url="http://codeharder.com"/>
    <add name="Stackoverflow" url="http://www.stackoverflow.com"/>
  </namedUrls>
</namedUrlSection>

And the accompanying code to read it:

public class UrlConfigSection : ConfigurationSection
{
    public static UrlConfigSection ConfigSection = ConfigurationManager.GetSection("namedUrlSection") as UrlConfigSection;

    [ConfigurationProperty("favoriteUrl")]
    public string Favorite
    {
        get
        {
            return this["favoriteUrl"].ToString();
        }
    }

    [ConfigurationProperty("namedUrls")]
    public NamedUrlCollection Urls
    {
        get
        {
            return this["namedUrls"] as NamedUrlCollection;
        }
    }
}

If you wanted to get the name of your favorite URL, it is very simple syntax.

string favUrlName = UrlConfigSection.ConfigSection.Favorite;

But, when you want to access one of the child namedUrl elements, it just doesn’t look very nice. Not ugly, just verbose. Wouldn’t you agree?

UrlConfigSection.ConfigSection.Urls["CodeHarder"].Url

I always wished I could just flatten it out to something like .CodeHarder. I don’t know why I didn’t think of this before, but with the new DynamicObject in .net4 I can! Creating a wrapper to give me that syntax is ~10 lines of code.

public class DynamicUrlConfig:DynamicObject
{
    public override bool TryGetMember(GetMemberBinder binder, out object result)
    {
        result = null;
        NamedUrl url = UrlConfigSection.ConfigSection.Urls[binder.Name];
                    
        if (url != null)
        {
            result = url.Url;
            return true;
        }
        return false;
    }
}

Now, when I want to get anything from the namedUrls section, I can use the syntax I always wanted.

dynamic urlSection = new DynamicUrlConfig();
string favUrl = urlSection.CodeHarder;

I know this isn’t new, and a quick google would probably give me several people who have done it before, but I was quite pleased and thought I would share.

.net, Fun with .net programming, dynamic, configuration, .net4