Enable input Accessory View for RCTTextField

Some keyboard types does not have buttons correspondent for keyReturnType such as Next, Done. It is observable on IPhone for numeric keyboard types. That prevents traversing forms with "number" input fields and impacts end-user experience.

The improvement allows application for adding extra buttons via inputAccessoryView.
Because RCTText is not a project exposed to React application calling all methods to add a handler is done using selectors.

Here is a code fragment which has an example on how to achieve it:
Within application:
facebook#1 Create a keyboard Handle
 KeyboardAccessory keyboardHandler = ^UIView *(UITextField *textField) {
    ReactTextAdapter *kAdapter = [[ReactTextAdapter alloc] init:textField];
    return [kAdapter getInputAccessory];
  };

2. Register an adapter

  Class clz = NSClassFromString(@"RCTTextField");

  SEL selector = NSSelectorFromString(@"registerForKeyboardType:handler:");
  if ([clz respondsToSelector:selector]) {
  [   clz performSelector:selector withObject:[NSNumber numberWithInt:UIKeyboardTypeNumberPad] withObject:keyboardHandler];
  }

facebook#3 Example of Keyboard Adapter

@interface ReactTextAdapter :UIToolbar

-(instancetype) init:(UITextField *)textField;
-(UIView *)getInputAccessory;

@EnD

//
//  ReactTextAdapter.m
//  KeyboardTest
//
//  Created by Krivopaltsev, Eugene on 3/11/16.
//

#import "ReactTextAdapter.h"

@interface ReactTextAdapter()

@Property (nonatomic) UITextField *textField;

//@Property (nonatomic)UIToolbar *toolBar;
@Property (nonatomic)UIBarButtonItem *flexible;

@EnD

@implementation ReactTextAdapter

-(instancetype) init:(UITextField *)textField {
  self = [super init];
  if (self) {
    self.textField = textField;

    [self setBarStyle:UIBarStyleDefault];
    self.translatesAutoresizingMaskIntoConstraints = NO;
    self.flexible = [[UIBarButtonItem alloc]
                     initWithBarButtonSystemItem:UIBarButtonSystemItemFlexibleSpace
                     target:self action:nil];

    // since there is a next field, add a NEXT button to the picker
    if (self. textField. returnKeyType == UIReturnKeyNext) {
      NSString *nextText = @"Next";
      UIBarButtonItem *nextButton = [[UIBarButtonItem alloc] initWithTitle:nextText
                                                                   style:UIBarButtonItemStyleDone
                                                                  target:self
                                                                  action:@selector(next)];

      self.items = [[NSArray alloc] initWithObjects: self.flexible, nextButton, nil];
    }else if (self.textField. returnKeyType == UIReturnKeyContinue) {

      NSString *continueText = @"Continue";
      UIBarButtonItem *contButton = [[UIBarButtonItem alloc] initWithTitle:continueText
                                                                     style:UIBarButtonItemStyleDone
                                                                    target:self
                                                                    action:@selector(next)];

      self.items = [[NSArray alloc] initWithObjects: self.flexible, contButton, nil];
    }
    else if (self. textField.returnKeyType == UIReturnKeyDone) {

      NSString *doneText = @"Done";
      UIBarButtonItem *doneButton = [[UIBarButtonItem alloc] initWithTitle:doneText
                                                                     style:UIBarButtonItemStyleDone
                                                                    target:self
                                                                    action:@selector(done)];
      doneButton.enabled = YES;

      self.items = [[NSArray alloc] initWithObjects: self.flexible, doneButton, nil];
    }

  }
  return self;
}
-(void) done {
  [self passToReactNative];
  [self.textField resignFirstResponder];
}

-(void) next {
  [self passToReactNative];
}

-(void) passToReactNative {
  SEL selector = @selector(textFieldSubmitEditing);
  if ([self.textField respondsToSelector:selector]) {
    [self.textField performSelector:selector withObject:nil];
  }
}

-(UIView *)getInputAccessory {
  return self;
}

Libraries/Text/RCTTextField.m

@@ -14,6 +14,16 @@
 #import "RCTUtils.h"
 #import "UIView+React.h"
 
+//
+// Repository of accessory Handles
+//
+
+static NSMutableDictionary *textFieldAccessoryMapping;
+
+// input View Accessory Handle definition
+
+typedef UIView * (^KeyboardAccessory)(UITextField *);
+
 @implementation RCTTextField
 {
   RCTEventDispatcher *_eventDispatcher;
@@ -257,6 +267,13 @@ - (BOOL)canBecomeFirstResponder
 
 - (void)reactWillMakeFirstResponder
 {
+
+  // This fragment was added to let application inject input accessory view if needed
+  //
+  KeyboardAccessory handler = [RCTTextField getAcessoryMapping][[NSNumber numberWithInt:self.keyboardType]];
+  if (handler) {
+    self.inputAccessoryView = handler(self);
+  }
   _jsRequestingFirstResponder = YES;
 }
 
@@ -279,4 +296,28 @@ - (BOOL)resignFirstResponder
   return result;
 }
 
+
++(NSMutableDictionary*)getAcessoryMapping {
+  static dispatch_once_t onceToken = 0;
+
+  dispatch_once(&onceToken, ^{
+    textFieldAccessoryMapping = [[NSMutableDictionary alloc] init];
+    // Do any other initialisation stuff here
+  });
+
+  return textFieldAccessoryMapping;
+}
+
+/**
+ * The method to allow application register for injecting inputAccessoryView for particular keyboard type
+ * handler presents instancdispatch_oncee of KeyboardAccessory type
+ */
+
++(void) registerForKeyboardType:(NSNumber *)type handler:(KeyboardAccessory)handler{
+
+  NSMutableDictionary *dct = [RCTTextField getAcessoryMapping];
+  dct[type] = handler;
+
+}
+
 @end