diff --git a/Examples/Objective-C/Podfile.lock b/Examples/Objective-C/Podfile.lock
index 0a609a3f..906962d1 100644
--- a/Examples/Objective-C/Podfile.lock
+++ b/Examples/Objective-C/Podfile.lock
@@ -43,7 +43,7 @@ PODS:
   - XLData/RemoteDataStore (2.0.0):
     - XLData/CoreRemote
     - XLData/DataStore
-  - XLForm (4.2.0)
+  - XLForm (4.3.0)
 
 DEPENDENCIES:
   - AFNetworking (~> 2.0)
@@ -78,8 +78,8 @@ SPEC CHECKSUMS:
   JVFloatLabeledTextField: 58a3a32cfb800e5b224f676987e7c13abf50a14d
   SHSPhoneComponent: 4cec0653a150ad63cbc52b0c8b29ce2d3c9c26f0
   XLData: df725c6179e2e0c80bf56a1ecad9afd169707a6d
-  XLForm: eb04ea4104f26250b70a72a7fa2eed3748dca5cd
+  XLForm: a439f9512078ed538e8335c8b06d3f3286bbfd37
 
 PODFILE CHECKSUM: 64fbcd03a2c13762b2c18e3938cc8008807937c9
 
-COCOAPODS: 1.9.3
+COCOAPODS: 1.11.3
diff --git a/Examples/Swift/SwiftExample/CustomRows/InlineSegmentedCell/InlineSegmentedCell.swift b/Examples/Swift/SwiftExample/CustomRows/InlineSegmentedCell/InlineSegmentedCell.swift
index e98f3a32..899b95a3 100644
--- a/Examples/Swift/SwiftExample/CustomRows/InlineSegmentedCell/InlineSegmentedCell.swift
+++ b/Examples/Swift/SwiftExample/CustomRows/InlineSegmentedCell/InlineSegmentedCell.swift
@@ -88,7 +88,7 @@ class InlineSegmentedControl : XLFormBaseCell, XLFormInlineRowDescriptorCell {
     
     var inlineRowDescriptor : XLFormRowDescriptor?
     lazy var segmentedControl : UISegmentedControl = {
-        return UISegmentedControl.autolayout()!
+        return UISegmentedControl.autolayout()
     }()
     
     override func configure() {
diff --git a/XLForm/XL/NSArray+XLFormAdditions.h b/XLForm/XL/NSArray+XLFormAdditions.h
index 9ae99440..7207aed5 100644
--- a/XLForm/XL/NSArray+XLFormAdditions.h
+++ b/XLForm/XL/NSArray+XLFormAdditions.h
@@ -27,6 +27,6 @@
 
 @interface NSArray (XLFormAdditions)
 
--(NSInteger)formIndexForItem:(id)item;
+-(NSInteger)formIndexForItem:(nonnull id)item;
 
 @end
diff --git a/XLForm/XL/NSArray+XLFormAdditions.m b/XLForm/XL/NSArray+XLFormAdditions.m
index 28eda59e..434b3b63 100644
--- a/XLForm/XL/NSArray+XLFormAdditions.m
+++ b/XLForm/XL/NSArray+XLFormAdditions.m
@@ -28,7 +28,7 @@
 
 @implementation NSArray (XLFormAdditions)
 
--(NSInteger)formIndexForItem:(id)item
+-(NSInteger)formIndexForItem:(nonnull id)item
 {
     for (id selectedValueItem in self) {
         if ([[selectedValueItem valueData] isEqual:[item valueData]]){
diff --git a/XLForm/XL/NSExpression+XLFormAdditions.h b/XLForm/XL/NSExpression+XLFormAdditions.h
index 6052833a..28ed545d 100644
--- a/XLForm/XL/NSExpression+XLFormAdditions.h
+++ b/XLForm/XL/NSExpression+XLFormAdditions.h
@@ -28,6 +28,6 @@
 
 @interface NSExpression (XLFormAdditions)
 
--(NSMutableArray*) getExpressionVars;
+-(nullable NSMutableArray*) getExpressionVars;
 
 @end
diff --git a/XLForm/XL/NSExpression+XLFormAdditions.m b/XLForm/XL/NSExpression+XLFormAdditions.m
index 55f7bcff..7e86139a 100644
--- a/XLForm/XL/NSExpression+XLFormAdditions.m
+++ b/XLForm/XL/NSExpression+XLFormAdditions.m
@@ -29,7 +29,7 @@
 @implementation NSExpression (XLFormAdditions)
 
 
--(NSMutableArray*) getExpressionVars{
+-(nullable NSMutableArray*) getExpressionVars{
     switch (self.expressionType) {
         case NSFunctionExpressionType:{
             NSString* str = [NSString stringWithFormat:@"%@", self];
@@ -38,11 +38,9 @@ -(NSMutableArray*) getExpressionVars{
             else
                 str = [str substringFromIndex:1];
             return [[NSMutableArray alloc] initWithObjects: str, nil];
-            break;
         }
         default:
             return nil;
-            break;
     }
 }
 
diff --git a/XLForm/XL/NSObject+XLFormAdditions.h b/XLForm/XL/NSObject+XLFormAdditions.h
index fd9fe246..49ff15fc 100644
--- a/XLForm/XL/NSObject+XLFormAdditions.h
+++ b/XLForm/XL/NSObject+XLFormAdditions.h
@@ -27,7 +27,7 @@
 
 @interface NSObject (XLFormAdditions)
 
--(NSString *)displayText;
--(id)valueData;
+-(nullable NSString *)displayText;
+-(nullable id)valueData;
 
 @end
diff --git a/XLForm/XL/NSObject+XLFormAdditions.m b/XLForm/XL/NSObject+XLFormAdditions.m
index 13b6214e..78e2420d 100644
--- a/XLForm/XL/NSObject+XLFormAdditions.m
+++ b/XLForm/XL/NSObject+XLFormAdditions.m
@@ -29,7 +29,7 @@
 
 @implementation NSObject (XLFormAdditions)
 
--(NSString *)displayText
+-(nullable NSString *)displayText
 {
     if ([self conformsToProtocol:@protocol(XLFormOptionObject)]){
         return [(id<XLFormOptionObject>)self formDisplayText];
@@ -40,7 +40,7 @@ -(NSString *)displayText
     return nil;
 }
 
--(id)valueData
+-(nullable id)valueData
 {
     if ([self isKindOfClass:[NSString class]] || [self isKindOfClass:[NSNumber class]] || [self isKindOfClass:[NSDate class]]){
         return self;
diff --git a/XLForm/XL/NSPredicate+XLFormAdditions.h b/XLForm/XL/NSPredicate+XLFormAdditions.h
index 181a2b84..107f04b1 100644
--- a/XLForm/XL/NSPredicate+XLFormAdditions.h
+++ b/XLForm/XL/NSPredicate+XLFormAdditions.h
@@ -27,5 +27,5 @@
 
 @interface NSPredicate (XLFormAdditions)
 
--(NSMutableArray*) getPredicateVars;
+-(nonnull NSMutableArray*) getPredicateVars;
 @end
diff --git a/XLForm/XL/NSPredicate+XLFormAdditions.m b/XLForm/XL/NSPredicate+XLFormAdditions.m
index 75fa9adc..625a8661 100644
--- a/XLForm/XL/NSPredicate+XLFormAdditions.m
+++ b/XLForm/XL/NSPredicate+XLFormAdditions.m
@@ -28,7 +28,7 @@
 @implementation NSPredicate (XLFormAdditions)
 
 
--(NSMutableArray*) getPredicateVars{
+-(nonnull NSMutableArray*) getPredicateVars{
     NSMutableArray* ret = [[NSMutableArray alloc] init];
     if ([self isKindOfClass:([NSCompoundPredicate class])]) {
         for (id object in ((NSCompoundPredicate*) self).subpredicates ) {
diff --git a/XLForm/XL/NSString+XLFormAdditions.h b/XLForm/XL/NSString+XLFormAdditions.h
index 7cdc14b0..f9711687 100644
--- a/XLForm/XL/NSString+XLFormAdditions.h
+++ b/XLForm/XL/NSString+XLFormAdditions.h
@@ -28,8 +28,8 @@
 
 @interface NSString (XLFormAdditions)
 
--(NSPredicate *)formPredicate;
+-(nonnull NSPredicate *)formPredicate;
 
--(NSString *)formKeyForPredicateType:(XLPredicateType)predicateType;
+-(nonnull NSString *)formKeyForPredicateType:(XLPredicateType)predicateType;
 
 @end
diff --git a/XLForm/XL/NSString+XLFormAdditions.m b/XLForm/XL/NSString+XLFormAdditions.m
index 9f8bd5b4..3bb37f09 100644
--- a/XLForm/XL/NSString+XLFormAdditions.m
+++ b/XLForm/XL/NSString+XLFormAdditions.m
@@ -27,7 +27,7 @@
 
 @implementation NSString (XLFormAdditions)
 
--(NSPredicate *)formPredicate
+-(nonnull NSPredicate *)formPredicate
 {
     // returns an array of strings where the first one is the new string with the correct replacements
     // and the rest are all the tags that appear in the string
@@ -57,7 +57,7 @@ -(NSPredicate *)formPredicate
 }
 
 
--(NSString *)formKeyForPredicateType:(XLPredicateType)predicateType
+-(nonnull NSString *)formKeyForPredicateType:(XLPredicateType)predicateType
 {
     return [NSString stringWithFormat:@"%@-%@", self, (predicateType == XLPredicateTypeHidden ? @"hidden" : @"disabled") ];
 }
diff --git a/XLForm/XL/UIView+XLFormAdditions.h b/XLForm/XL/UIView+XLFormAdditions.h
index 34c1cef6..f26ff43b 100644
--- a/XLForm/XL/UIView+XLFormAdditions.h
+++ b/XLForm/XL/UIView+XLFormAdditions.h
@@ -28,9 +28,9 @@
 
 @interface UIView (XLFormAdditions)
 
-+(instancetype)autolayoutView;
--(NSLayoutConstraint *)layoutConstraintSameHeightOf:(UIView *)view;
--(UIView *)findFirstResponder;
--(UITableViewCell<XLFormDescriptorCell> *)formDescriptorCell;
++(nonnull instancetype)autolayoutView;
+-(nonnull NSLayoutConstraint *)layoutConstraintSameHeightOf:(nonnull UIView *)view;
+-(nullable UIView *)findFirstResponder;
+-(nullable UITableViewCell<XLFormDescriptorCell> *)formDescriptorCell;
 
 @end
diff --git a/XLForm/XL/UIView+XLFormAdditions.m b/XLForm/XL/UIView+XLFormAdditions.m
index c2bc45a6..678616b1 100644
--- a/XLForm/XL/UIView+XLFormAdditions.m
+++ b/XLForm/XL/UIView+XLFormAdditions.m
@@ -27,7 +27,7 @@
 
 @implementation UIView (XLFormAdditions)
 
-+ (instancetype)autolayoutView
++ (nonnull instancetype)autolayoutView
 {
     __kindof UIView *view = [self new];
     view.translatesAutoresizingMaskIntoConstraints = NO;
@@ -35,7 +35,7 @@ + (instancetype)autolayoutView
     return view;
 }
 
-- (NSLayoutConstraint *)layoutConstraintSameHeightOf:(UIView *)view
+- (nonnull NSLayoutConstraint *)layoutConstraintSameHeightOf:(nonnull UIView *)view
 {
     return [NSLayoutConstraint constraintWithItem:self
                                         attribute:NSLayoutAttributeHeight
@@ -46,7 +46,7 @@ - (NSLayoutConstraint *)layoutConstraintSameHeightOf:(UIView *)view
                                          constant:0.0];
 }
 
-- (UIView *)findFirstResponder
+- (nullable UIView *)findFirstResponder
 {
     UIView *firstResponder = nil;
     if (self.isFirstResponder) {
@@ -66,7 +66,7 @@ - (UIView *)findFirstResponder
     return firstResponder;
 }
 
-- (UITableViewCell<XLFormDescriptorCell> *)formDescriptorCell
+- (nullable UITableViewCell<XLFormDescriptorCell> *)formDescriptorCell
 {
     UITableViewCell<XLFormDescriptorCell> * tableViewCell = nil;