ResourceManager with External Localization Assembly



As a software developer I like to work with everything that is related to software Localization known as L10n. Besides being a developer working defining the architecture that will be adopted in a given project and doing the hard “FUN” work writing the code, I’m also a translator if you don’t know it yet.

One thing I've been trying to do recently is to be able to use localized strings that are present in an external assembly [ DLL ] using the ResourceManager object.
I have localized strings in resource [ .resx ] files that are specific for each locale I support. I place these .resx files in a separate class library project to maintain things organized.

So, suppose the namespace of this class library is MyProject.L10n and the .resx file name is Localization.resx. This gives me access to a class named Localization within the code. I also have Localization.pt.resx. I support English and Portuguese locales in my project for now. This naming pattern allows me to have in the future a file called Localization.es-ES.resx for Castilian Spanish (as written and spoken in Spain) and another one called Localization.es-AR.resx for Argentine Spanish. During runtime the .NET framework will select the correct .resx file to extract the localized string from based on the current culture the user has set while browsing my website.

After adding a reference to this class library, I'm able to use this code in my ASP.NET MVC project in a Razor view:

MyProject.L10n.Localization.LocalizedString;

This works as expected, but it's not what I need, though. As you see the localized string key [ LocalizedString ] is hard coded. I want to be able to use the method GetString from the ResourceManager object so that I can write code like this:

ResourceManager.GetString(item.DynamicLocalizedStringValue);

The problem and the catchy here is that in order to use the resource manager the way I want, I have to point it to the external assembly this way:

grid.Column(
columnName: "Type",
header: Localization.Type,format: (item) => new ResourceManager("MyProject.L10n.Localization", typeof(Localization).Assembly).GetString(item.Type.ToString()))

This part does the tricky: typeof(Localization).Assembly

In the code block above I’m using WebGrid that is a new helper that comes with ASP.NET MVC 3. It simplifies the task of rendering tabular data. When I do item.Type.ToString() I’m actually getting different values for each row of my grid and I pass this dynamic value to ResourceManager that in return gives me the translated/localized version of a give string key.

Going even further I’ve implemented a Razor’s Helper method in a file called Helpers.cshtml and placed such file inside the App_Code folder. This is the helper’s code:

@using System.Resources
@using MyProject.L10n

@helper GetLocalizedString(string stringValue)
{
    ResourceManager rm = new ResourceManager("MyProject.L10n.Localization", typeof (Localization).Assembly);

    @rm.GetString(stringValue);
}

Now it’s just a matter of calling the helper this way in whatever place/view I need it:

grid.Column(
columnName: "Type",
header: Localization.Type,
format: (item) => @Helpers.GetLocalizedString(item.Type.ToString()))

The above code is way more clear than the one I showed your before…

Hope this post helps shed some light in this subject since the only thing that should be done is to get a reference to the assembly that holds the Localization class and pass it to the ResourceManger’s constructor.