Fix applying underline to the whole text on singleline input blur

apple/MarkdownTextFieldObserver.h

@@ -10,6 +10,8 @@ NS_ASSUME_NONNULL_BEGIN
 
 - (void)textFieldDidChange:(UITextField *)textField;
 
+- (void)textFieldDidEndEditing:(UITextField *)textField;
+
 @end
 
 NS_ASSUME_NONNULL_END

apple/MarkdownTextFieldObserver.mm

@@ -44,4 +44,18 @@ - (void)textFieldDidChange:(__unused UITextField *)textField {
   [_textField setSelectedTextRange:textRange notifyDelegate:NO];
 }
 
+- (void)textFieldDidEndEditing:(__unused UITextField *)textField
+{
+  // In order to prevent iOS from applying underline to the whole text if text ends with a link on blur,
+  // we need to update `defaultTextAttributes` which at this point doesn't contain NSUnderline attribute yet.
+  // It seems like the setter performs deep comparision, so we differentiate the new value using a counter,
+  // otherwise this trick would work only once.
+  static NSAttributedStringKey RCTLiveMarkdownForceUpdateAttributeName = @"RCTLiveMarkdownForceUpdate";
+  static NSUInteger counter = 0;
+  NSMutableDictionary *defaultTextAttributes = [_textField.defaultTextAttributes mutableCopy];
+  defaultTextAttributes[RCTLiveMarkdownForceUpdateAttributeName] = @(counter++);
+  _textField.defaultTextAttributes = defaultTextAttributes;
+  [self textFieldDidChange:_textField];
+}
+
 @end

apple/MarkdownTextInputDecoratorView.mm

@@ -74,6 +74,7 @@ - (void)didMoveToWindow {
 
     // register observers for future edits
     [_textField addTarget:_markdownTextFieldObserver action:@selector(textFieldDidChange:) forControlEvents:UIControlEventEditingChanged];
+    [_textField addTarget:_markdownTextFieldObserver action:@selector(textFieldDidEndEditing:) forControlEvents:UIControlEventEditingDidEnd];
     [_textField addObserver:_markdownTextFieldObserver forKeyPath:@"text" options:NSKeyValueObservingOptionNew context:NULL];
     [_textField addObserver:_markdownTextFieldObserver forKeyPath:@"attributedText" options:NSKeyValueObservingOptionNew context:NULL];
 
@@ -132,6 +133,7 @@ - (void)willMoveToWindow:(UIWindow *)newWindow
 
   if (_textField != nil) {
     [_textField removeTarget:_markdownTextFieldObserver action:@selector(textFieldDidChange:) forControlEvents:UIControlEventEditingChanged];
+    [_textField removeTarget:_markdownTextFieldObserver action:@selector(textFieldDidEndEditing:) forControlEvents:UIControlEventEditingDidEnd];
     [_textField removeObserver:_markdownTextFieldObserver forKeyPath:@"text" context:NULL];
     [_textField removeObserver:_markdownTextFieldObserver forKeyPath:@"attributedText" context:NULL];
     _markdownTextFieldObserver = nil;