How Force browser to reload cached static file with versioning?

Question

After deploying a new version of a website the browser loads everything from its cache from the old webpage until a hard, force refresh is done.

In ASP.NET MVC if the file becomes in Bundle, it handled by Optimization framework. a version added to your file link, and if a change occurs in your bundle's file a new token generate. follow below code :

for example, js file name is: datatables

when you put it in a bundle with the same name, you will see the

datatables?v=anY9_bo7KitrGnXQr8ITP3ylmhQe9NDzSjgLpLQWQFE1

as a file name. change datatables and watch again the name of the file in the browser, surely it will change:

datatables?v=r8yhQBxKyDgrOGyqr1ndtdG92Ije09nqTY7yogrOSTk1

But there's two questions:

• What we can do if our file wasn't in Bundle?
• Is a way to force the browser to refresh cache?

Answer 1

Assuming you cannot use bundling for some reason, the solution suggested by the original poster is good enough, however it's better to put the logic inside a helper method.

It makes the code testable, it helps to change the logic without changing .cshtml , and also helps to not repeat the filename twice. Then you can have have a much cleaner code:

<script src="@Url.ContentWithVersion("~/scripts/main.js")"></script>

To do so, you can add ContentWithVersion extension method to the existing UrlHelper:

using System;
using System.IO;
using System.Web;
using System.Web.Mvc;
public static class UrlHelperExtensions
{
    public static string ContentWithVersion(this UrlHelper urlHelper, string path)
    {
        if (urlHelper == null)
            throw new ArgumentNullException(nameof(urlHelper));
        var result = urlHelper.Content(path);
        var file = HttpContext.Current.Server.MapPath(path);
        if (File.Exists(file))
            result += $"?v={File.GetLastWriteTime(file).ToString("yyyyMMddHHmmss")}";
        return result;
    }
}

Answer 2

we have one solution with some different way for implementation. we use above solution for it.

datatables?v=1

we can handle the version of the file, it's mean that every time that we change our file, change the version of it too. but it's not a suitable way.

another way used Guide, it wasn't suitable too, because each time it fetches the file and doesn't use from the browser cache.

datatables?v=Guid.NewGuid()

The last way that is the best Way is :

when file change occur , change version too. check follow code :

<script src="~/scripts/[email protected](Server.MapPath("/scripts/main.js")).ToString("yyyyMMddHHmmss")"></script>

by this way, when you change the file, LastWriteTime change too, so the version of the file will change and in the next when you open the browser, it detects a new file and fetch it.