Use ASP.NET Resource strings from within javascript files

Here is my solution for now. I am sure I will need to make it more versatile in the future... but so far this is good.

using System.Collections;
using System.Linq;
using System.Resources;
using System.Web.Mvc;
using System.Web.Script.Serialization;

public class ResourcesController : Controller
{
    private static readonly JavaScriptSerializer Serializer = new JavaScriptSerializer();

    public ActionResult GetResourcesJavaScript(string resxFileName)
    {
        var resourceDictionary = new ResXResourceReader(Server.MapPath("~/App_GlobalResources/" + resxFileName + ".resx"))
                            .Cast<DictionaryEntry>()
                            .ToDictionary(entry => entry.Key.ToString(), entry => entry.Value.ToString());
        var json = Serializer.Serialize(resourceDictionary);
        var javaScript = string.Format("window.Resources = window.Resources || {{}}; window.Resources.{0} = {1};", resxFileName, json);

        return JavaScript(javaScript);
    }

}

// In the RegisterRoutes method in Global.asax:
routes.MapRoute("Resources", "resources/{resxFileName}.js", new { controller = "Resources", action = "GetResourcesJavaScript" });

So I can do

<script src="/resources/Foo.js"></script>

and then my scripts can reference e.g. window.Resources.Foo.Bar and get a string.

whereas "Common" is the name of the resource file and Msg1 is the fieldname. This also works for culture changes.

            Partial Javascript...:
            messages: 
            {
                <%=txtRequiredField.UniqueID %>:{                       
                    required: "<%=Resources.Common.Msg1 %>",
                    maxlength: "Only 50 character allowed in required field."
                }
            }

If you have your resources in a separate assembly you can use the ResourceSet instead of the filename. Building on @Domenics great answer:

public class ResourcesController : Controller
{
    private static readonly JavaScriptSerializer Serializer = new JavaScriptSerializer();

    public ActionResult GetResourcesJavaScript()
    {
        // This avoids the file path dependency.
        ResourceSet resourceSet = MyResource.ResourceManager.GetResourceSet(CultureInfo.CurrentUICulture, true, true);

        // Create dictionary.
        var resourceDictionary = resourceSet
                        .Cast<DictionaryEntry>()
                        .ToDictionary(entry => entry.Key.ToString(), entry => entry.Value.ToString());
        var json = Serializer.Serialize(resourceDictionary);
        var javaScript = string.Format("window.Resources = window.Resources || {{}}; window.Resources.resources = {1};", json);

        return JavaScript(javaScript);
    }
}

The downside is that this will not enable more than one resource-file per action. In that way @Domenics answer is more generic and reusable.

You may also consider using OutputCache, since the resource won't change a lot between requests.

[OutputCache(Duration = 3600, Location = OutputCacheLocation.ServerAndClient)]
public ActionResult GetResourcesJavaScript()
{ 
    // Logic here...
}

http://www.asp.net/mvc/overview/older-versions-1/controllers-and-routing/improving-performance-with-output-caching-cs

In a nutshell, make ASP.NET serve javascript rather than HTML for a specific page. Cleanest if done as a custom IHttpHandler, but in a pinch a page will do, just remember to:

1) Clear out all the ASP.NET stuff and make it look like a JS file.

2) Set the content-type to "text/javascript" in the codebehind.

Once you have a script like this setup, you can then create a client-side copy of your resources that other client-side scripts can reference from your app.

I usually pass the resource string as a parameter to whatever javascript function I'm calling, that way I can continue to use the expression syntax in the HTML.

I the brown field application I'm working on we have an xslt that transforms the resx file into a javascript file as part of the build process. This works well since this is a web application. I'm not sure if the original question is a web application.

use a hidden field to hold the resource string value and then access the field value in javascript for example : " />

var todayString= $("input[name=TodayString][type=hidden]").val();

Add the function in the BasePage class:

    protected string GetLanguageText(string _key)
    {
        System.Resources.ResourceManager _resourceTemp = new System.Resources.ResourceManager("Resources.Language", System.Reflection.Assembly.Load("App_GlobalResources"));
        return _resourceTemp.GetString(_key);
    }

Javascript:

    var _resurceValue = "<%=GetLanguageText("UserName")%>";

or direct use:

    var _resurceValue = "<%= Resources.Language.UserName %>";

Note: The Language is my resouce name. Exam: Language.resx and Language.en-US.resx