Friday, October 14, 2011

ASP.NET MVC Localization: Generate resource files and localized views using custom templates

Overriding ASP.NET MVC custom templates

The Add View dialog perform code generation that use T4 templates behind the scenes. These templates can be modified to customize the generated code from these tools. You can also add custom templates.

Basically you have to copy the default templates to your project. This is the path:

[Visual Studio Install Directory]\Common7\IDE\ItemTemplates\[CSharp | VisualBasic]\Web\MVC\CodeTemplates\

I have created a custom template that generates resource files (.resx), and I have modified the default templates to use the generated resource files.

You can find more information here:

T4 Templates: A Quick-Start Guide for ASP.NET MVC Developers

Understanding .resx file format

From MSDN [1]:

The .resx resource file format consists of XML entries, which specify objects and strings inside XML tags. One advantage of a .resx file is that when opened with a text editor (such as Notepad or Microsoft Word) it can be written to, parsed, and manipulated.(…) Each entry is described as a name/value pair.(…) When a string is added to a .resx file, the name of the string is embedded in a <data> tag, and the value is enclosed in a<value> tag

For a resource file like this:

You have the corresponding XML:

I created a custom template that generates the resource file in the specified format.

Creating resource files

Add a strongly-type view using the custom template and the resource file will be generated for you:

This is the generated file:

It’s necessary to edit the generated text. I decided to surround some properties with[[propertie-name]] – this way is easy to replace it using Find-Replace inside a text editor. Don’t forget to set the Access Modifier property to Public