Return to app behavior after phone call different in native code than UIWebView

Question

According to Apple's documentation, in order to make phone call from my app, I need to implement the following protocols:

HTML link:

<a href="tel:1-408-555-5555">1-408-555-5555</a>

Native application URL string:

tel:1-408-555-5555

However, upon completion of a phone call initiated from an HTML link inside a UIWebView, I am redirected right back to my application. But upon completion of a phone call made from a native application URL string, my iphone stays in the iphone's regular phone application, and if I want to return to my application I have to do so manually.

As far as I can tell from reading what others have said, there is no way to change this behavior.

Here is my question:

1. Is it true that it's impossible to return to an application after making a phone call from a native application URL string?
2. Would there be any downside to implementing a UIWebView instead of a UILabel in situations where I really wanted the user to be redirected back to my application after completing a phone call?

Answer 1

The simplest way seems to be:

[[UIApplication sharedApplication] openURL:[NSURL URLWithString:@"telprompt:0123456789"]];

You will get a prompt and your app will regain focus after the call is finished.

Answer 2

1. Behavior does differ between calling -[UIApplication openURL:] with a tel: URL, and clicking a link to the same URL in a UIWebView.

2. Using a UIWebView instead of a UILabel might have some downsides, but you don't have to actually display the UIWebView to get its tel URL handling behavior. Instead, just load a tel URL request in an instance of UIWebView without adding it to your view hierarchy.

For example:

#import <Foundation/Foundation.h>
#import <UIKit/UIKit.h>

@interface PhoneCaller : NSObject
{
  @private
    UIWebView *webview;
}
- (void)callTelURL:(NSURL *)url;
@end

@implementation
- (id)init
{
    self = [super init];
    if (self)
    {
        webview = [[UIWebView alloc] init];
    }
    return self;
}
- (void)callTelURL:(NSURL *)url
{
    [webview loadRequest:[NSURLRequest requestWithURL:url]];
}
- (void)dealloc
{
    [webview release];
    [super dealloc];
}
@end

Answer 3

Allow me to simplify a bit. All you need is this little snippet:

UIWebView *callWebview = [[UIWebView alloc] init];
NSURL *telURL = [NSURL URLWithString:@"tel:number-to-call"];
[callWebview loadRequest:[NSURLRequest requestWithURL:telURL]];

which I got here.

*Recently tested successfully on iOS 5.0.

Answer 4

The Eric's Brotto method still works in 5.1. You have to add the webview to the main view before the loadRequest, like this:

NSString *cleanedString = [[phoneNumber componentsSeparatedByCharactersInSet:[[NSCharacterSet characterSetWithCharactersInString:@"0123456789-+()"] invertedSet]] componentsJoinedByString:@""];
NSString *escapedPhoneNumber = [cleanedString stringByAddingPercentEscapesUsingEncoding:NSUTF8StringEncoding];
NSURL *telURL = [NSURL URLWithString:[NSString stringWithFormat:@"tel://%@", escapedPhoneNumber]];
UIWebView *mCallWebview = [[UIWebView alloc] init]  ;
[self.view addSubview:mCallWebview];
[mCallWebview loadRequest:[NSURLRequest requestWithURL:telURL]]; 

(I added a phone number cleaner, to delete any non-number char that blocks this method)