ASP.NET Web Api - How to Detect if Request is from Mobile in ApiController

Question

I have an old Controller class in my company which inherits ApiController.

One of the actions are a POST endpoint that receives data from browser.

Since I'm in the ApiController, I don't have the built-in property IsMobile to detect.

So, How do I Detect if Request is from Mobile in ApiController ?

Any alternatives to suggests ?

Answer 1

You might look at the User-Agent header, and look for hints of mobile client:

var userAgent = Request.Headers.UserAgent.ToString();

You might be able to look for certain strings like 'mobile' or 'mobi' (or search for multiple alternative keywords).

Here's a page that lists mobile client user agents: https://developers.whatismybrowser.com/useragents/explore/hardware_type_specific/mobile/7

Update:

Here's a library that's already doing something similar with the user-agent header: https://github.com/wangkanai/Detection

Answer 2

As suggested by the initial answers, the key is using UserAgent. I found this answer which I wrapped up in an ActionFilter in case I would like to use it thou out multiple actions

/// <summary>
/// This action filter sets Request's properties with a "BrowserCapabilitiesFactory" object. <br/>
/// To get it, use <b>Request.Properties.TryGetValue("UserBrowser", out yourObjectToSet);</b>. <br/>
/// With that, you can check browser details of the request. Use this for <b>ApiController</b> actions. <br/>
/// If browser was not found or any exception occured in filter, then the value of the key will be set to null, 
/// By doing that , ensures that the Properties will always have a key-value of UserBrowser
/// </summary>
public class GetUserBrowserActionFilter : ActionFilterAttribute
{
    public override void OnActionExecuting(HttpActionContext actionContext)
    {
        base.OnActionExecuting(actionContext);
        try
        {
            // ============================== Get User agent and parse it to a strongly type object ============================== //
            var userAgent = HttpContext.Current.Request.UserAgent;
            var userBrowser = new HttpBrowserCapabilities { Capabilities = new Hashtable { { string.Empty, userAgent } } };
            var factory = new BrowserCapabilitiesFactory();
            factory.ConfigureBrowserCapabilities(new NameValueCollection(), userBrowser);
            actionContext.Request.Properties.Add("UserBrowser", userBrowser);
        }
        catch (Exception ex)
        {
            actionContext.Request.Properties.Add("UserBrowser", null);
        }

    }
}