Add method for formatting (possibly regional) phone numbers in an "absolute" international way.

RMPhoneFormat/RMPhoneFormat.h

@@ -35,6 +35,7 @@
 - (id)initWithDefaultCountry:(NSString *)countryCode;
 
 - (NSString *)format:(NSString *)str;
+- (NSString *)absoluteInternationalFormat:(NSString *)str;
 
 // Calling code for the user's default country based on their Region Format setting
 - (NSString *)defaultCallingCode;

RMPhoneFormat/RMPhoneFormat.m

@@ -763,6 +763,55 @@ - (NSString *)format:(NSString *)orig {
     //return orig;
 }
 
+- (NSString *)absoluteInternationalFormat:(NSString *)orig {
+    // Don't deal with invalid numbers.
+    if (![self isPhoneNumberValid:orig]) {
+        return nil;
+    }
+
+    NSString *str = [RMPhoneFormat strip:orig];
+
+    if ([str hasPrefix:@"+"]) {
+        // This is already an absolute number -- return the stripped version.
+        return str;
+    }
+
+    CallingCodeInfo *info = [self callingCodeInfo:_defaultCallingCode];
+    if (info == nil) {
+        // No way to determine absolute international format for this number.
+        return nil;
+    }
+
+    NSString *absoluteInternational;
+
+    // See if the entered number begins with an access code valid for the user's region format.
+    NSString *accessCode = [info matchingAccessCode:str];
+    if (accessCode) {
+        // Strip off the access code -- the rest should start with a country code followed by
+        // the regional number.
+        NSString *rest = [str substringFromIndex:[accessCode length]];
+        absoluteInternational = [@"+" stringByAppendingString:rest];
+    } else {
+        // No international prefix.
+        NSString *trunkCode = [info matchingTrunkCode:str];
+        if (trunkCode.length) {
+            str = [str substringFromIndex:trunkCode.length];
+        }
+
+        // Attempt to create a full-fledged +xx number from this number to see if it's valid.
+        absoluteInternational = [NSString stringWithFormat:@"+%@%@", info.callingCode, str];
+    }
+
+    if (![self isPhoneNumberValid:absoluteInternational]) {
+        // This might not be valid eg. in the case of regional numbers, like
+        // 555-5555 in the US — not direct-dialable from outside the country.
+        return nil;
+    }
+
+    return absoluteInternational;
+}
+
+
 - (BOOL)isPhoneNumberValid:(NSString *)phoneNumber {
     // First remove all added punctuation to get just raw phone number characters.
     NSString *str = [RMPhoneFormat strip:phoneNumber];

RMPhoneFormat/RMViewController.m

@@ -34,6 +34,7 @@ @implementation RMViewController {
     RMPhoneFormat *_phoneFormat;
     NSMutableCharacterSet *_phoneChars;
     UITextField *_textField;
+    UILabel *_absoluteNumberLabel;
 }
 
 - (id)init {
@@ -92,6 +93,22 @@ - (BOOL)textField:(UITextField *)textField shouldChangeCharactersInRange:(NSRang
     BOOL valid = [_phoneFormat isPhoneNumberValid:phone];
 
     textField.textColor = valid ? [UIColor blackColor] : [UIColor redColor];
+
+    if (valid) {
+        NSString *absoluteNumber = [_phoneFormat absoluteInternationalFormat:txt];
+
+        if (absoluteNumber) {
+            _absoluteNumberLabel.text = absoluteNumber;
+        } else {
+            _absoluteNumberLabel.text = @"(Valid regional number, but no given area code)";
+        }
+        _absoluteNumberLabel.textColor = [UIColor blackColor];
+    } else {
+        textField.textColor = [UIColor redColor];
+
+        _absoluteNumberLabel.text = @"(Not a valid number)";
+        _absoluteNumberLabel.textColor = [UIColor darkGrayColor];
+    }
 
     // If these are the same then just let the normal text changing take place
     if ([phone isEqualToString:txt]) {
@@ -141,12 +158,15 @@ - (void)viewDidLoad {
 
     self.view.backgroundColor = [UIColor lightGrayColor];
 
-    UIView *bg = [[UIView alloc] initWithFrame:CGRectMake(20, 40, self.view.frame.size.width - 40, 44)];
+    CGRect bgFrame = CGRectMake(20, 40, self.view.frame.size.width - 40, 44);
+    UIView *bg = [[UIView alloc] initWithFrame:bgFrame];
     bg.autoresizingMask = UIViewAutoresizingFlexibleWidth;
     bg.backgroundColor = [UIColor whiteColor];
     bg.layer.cornerRadius = 10;
 
-    UITextField *tf = [[UITextField alloc] initWithFrame:CGRectMake(10, 10, bg.frame.size.width - 20, 24)];
+    // The text field where you type the number.
+    CGRect tfFrame = CGRectMake(10, 10, bg.frame.size.width - 20, 24);
+    UITextField *tf = [[UITextField alloc] initWithFrame:tfFrame];
     tf.keyboardType = UIKeyboardTypePhonePad;
     tf.backgroundColor = [UIColor whiteColor];
     tf.clearButtonMode = UITextFieldViewModeWhileEditing;
@@ -159,6 +179,16 @@ - (void)viewDidLoad {
     [self.view addSubview:bg];
 
     _textField = tf;
+
+    // Label below the text field showing the absolute international number.
+    CGRect absoluteFrame = CGRectMake(bgFrame.origin.x,
+                                      bgFrame.origin.y + bgFrame.size.height + 10.0,
+                                      bgFrame.size.width,
+                                      16.0);
+    _absoluteNumberLabel = [[UILabel alloc] initWithFrame:absoluteFrame];
+    _absoluteNumberLabel.font = [UIFont systemFontOfSize:13.0];
+    _absoluteNumberLabel.backgroundColor = [UIColor clearColor];
+    [self.view addSubview:_absoluteNumberLabel];
 }
 
 - (void)viewWillAppear:(BOOL)animated {