{version} wildcard in MVC4 Bundle

Question

In MVC 4 we have bundles. While defining the bundles we can use wildcards like * for all files in a folder.

In the example below what does -{version} mean?

public static void RegisterBundles(BundleCollection bundles)
{
    bundles.Add(new ScriptBundle("~/bundles/jquery").Include(
        "~/Scripts/jquery-{version}.js"));
}

Answer 1

The -{version} basically maps to a version regex, or to be precise: (\d+(?:\.\d+){1,3}).
Using * tends to grab too much, for example if you bundle jquery*, that will include jquery-ui as well which might mess up the ordering. But using jquery-{version}.js would let you avoid having to update your bundle definition every time you upgrade jquery.

Additional things to note:

• {version} only works for the last part of the path--basically the file name--not a directory.
• multiple version of jquery in the same folder will all get caught up.

Answer 2

This bundle is able to accomodate version numbers in script names. So updating jQuery to a new version in your application (via NuGet or manually) doesn't require any code / markup changes.

See the following link for more information on bundling: http://weblogs.asp.net/jgalloway/archive/2012/08/16/asp-net-4-5-asp-net-mvc-4-asp-net-web-pages-2-and-visual-studio-2012-web-developer-features.aspx