What HTTP User-Agent does my iOS program advertise itself as?

Question

I've written an app for my podcast, Otaku no Podcast. In various parts of the app, I use NSURLConnection (fetch RSS feeds), UIWebView (display website content), AVPlayer (play MP3 audio files off our CDN), and MPMoviePlayerViewController (play video files off our CDN). Now, since all of these make HTTP requests of some sort, I'm assuming that they will advertise themselves with the standard iPhone User-agent string. (if my assumption is incorrect please let me know) This means that, based on reading my log files, I have no way of telling which of my visitors is coming in via plain old mobile Safari, vs. using my app.

Is there a way of changing the User-Agent to one of my own? I found this question on SO that describes how to do this with NSURL but I can't find any information about any of the above classes that I am using.

Answer 1

Your original assumption is partly incorrect- A custom User-agent string is used for NSURLRequests from your app. In my testing, the string is

<product-name>/<build-number> CFNetwork/548.0.3 Darwin/11.2.0

However, some requests from UIWebView use this user-agent string

Mozilla/5.0 (iPhone Simulator; CPU iPhone OS 5_0 like Mac OS X) AppleWebKit/534.46 (KHTML, like Gecko) Mobile/9A334

presumably so that websites can optimise their HTML for the device even if it's not MobileSafari.

Answer 2

According to this blog post, you may be able to set a pseudo-global User-Agent string (pseudo in that I'm not sure which other classes outside of UIWebView use it).

Here is the class method to add to your main controller (or app delegate) :

+ (void)initialize {
    // Set user agent (the only problem is we can't modify it later)
    NSDictionary *dictionary =
    [[NSDictionary alloc] initWithObjectsAndKeys:
     @"Your desired user agent", @"UserAgent", nil];
    [[NSUserDefaults standardUserDefaults] registerDefaults:dictionary];
    [dictionary release];
}

According to the comments on that post, "we can't modify it later" is a bit of an overstatement: you can modify the UserAgent value later, but you have to release and re-alloc any UIWebViews (and I presume NSURLConnections if they use it too) for the changes to take effect.

Answer 3

Looking at this related question ( Changing the userAgent of NSURLConnection ), it looks like it is pretty easy to make a user-agent change for NSURLConnection.

As for the other classes (UIWebView, AVPlayer, MPMoviePlayerViewController), there's no easy way to mess with the underlying NSURLConnections.

If you really want to change the user-agent for all HTTP requests, I'd suggest looking into Objective-C Class Posing to replace NSURLConnection (which hopefully wouldn't require completely reimplementing it).