UserAgent Parser (based on ua_parser C# Library)

This is the ASP.NET Core implementation of ua-parser.

The implementation uses the shared regex patterns and overrides from regexes.yaml (found in uap-core). The assembly embeds the latest regex patterns (enabled through a node module) which are loaded into the default parser. You can create a parser with more updated regex patterns by using the static methods on Parser to pass in specific patterns in yaml format.

Build and Run Tests

---

You can then build and run the tests by

> dotnet restore UAParser.Core.sln

> dotnet test UAParser.Core.sln

Update the embedded regexes

To pull the latest regexes into the project:

> npm install
> npm run update

How to use ?

Step 1: Install the UAParser.Core nuget package

> Install-Package UAParser.Core

Step 2: Enable the browser detection service inside the ConfigureServices method of Startup.cs.

public void ConfigureServices(IServiceCollection services)
{
    // Add user agent service
    services.AddUserAgentParser();

    services.AddMvc();
}

Step 3: Inject IUserAgentParser to your controller class or view file or middleware and access the ClientInfo property.

Example usage in controller code

public class HomeController : Controller
{
    private readonly IUserAgentParser userAgentParser;
    public HomeController(IUserAgentParser parser)
    {
        this.userAgentParser = parser;
    }
    public IActionResult Index()
    {
        var clientInfo = this.userAgentParser.ClientInfo;
        // Use ClientInfo object as needed.

        return View();
    }
}

Example usage in view code

@inject UAParser.Interfaces.IUserAgentParser parser

<h2> @parser.ClientInfo.Browser.Family </h2>
<h3> @parser.ClientInfo.Browser.Version </h3>
<h3> @parser.ClientInfo.OS.ToString() </h3>
<h3> @parser.ClientInfo.Device.ToString() </h3>

Optional: detect Windows 11. Windows 11 browsers still send Windows NT 10.0 in the User-Agent string, so the string alone reports Windows 10. Chromium based browsers (Edge, Chrome, Opera) can report the real version through the Sec-CH-UA-Platform-Version client hint, but only when the server asks for it. Add the middleware to request it:

app.UseUserAgentClientHints();

This sends Accept-CH and Critical-CH response headers (pass critical: false to skip Critical-CH, then the hint is only available from the second request on). When the hint reports Windows 11, ClientInfo.OS is Windows 11 (Major = "11"). Client hints are only sent over HTTPS; Firefox and Safari don't send them, so they keep reporting Windows 10. If you cache responses that depend on the OS, add Sec-CH-UA-Platform-Version to the Vary header.

Example usage in custom middlware

You can inject the IUserAgentParser to the InvokeAsync method.

public class MyCustomMiddleware
{
    private RequestDelegate next;
    public MyCustomMiddleware(RequestDelegate next)
    {
        this.next = next;
    }
    public async Task InvokeAsync(HttpContext httpContext, IUserAgentParser parser)
    {
        var clientInfo = parser.ClientInfo;

        if (clientInfo.Browser.Family == "Edge")
        {
            await httpContext.Response.WriteAsync("Have you tried the new chromuim based edge ?");
        }
        else
        {
            await this.next.Invoke(httpContext);
        }
    }
}

Authors:

• Søren Enemærke @sorenenemaerke / github
• Atif Aziz @raboof / github