Simplified the widget.onChanged call expression.

Author: awhitford

lib/src/fields/form_builder_checkbox.dart

@@ -79,7 +79,7 @@ class _FormBuilderCheckboxState extends State<FormBuilderCheckbox> {
           : (bool value) {
               FocusScope.of(context).requestFocus(FocusNode());
               field.didChange(value);
-              if (widget.onChanged != null) widget.onChanged(value);
+              widget.onChanged?.call(value);
             },
     );
   }

lib/src/fields/form_builder_checkbox_list.dart

@@ -85,7 +85,7 @@ class _FormBuilderCheckboxListState extends State<FormBuilderCheckboxList> {
                 currValue.remove(widget.options[i].value);
               }
               field.didChange(currValue);
-              if (widget.onChanged != null) widget.onChanged(currValue);
+              widget.onChanged?.call(currValue);
             },
     );
   }

lib/src/fields/form_builder_chips_input.dart

@@ -121,7 +121,7 @@ class _FormBuilderChipsInputState extends State<FormBuilderChipsInput> {
           findSuggestions: widget.findSuggestions,
           onChanged: (data) {
             field.didChange(data);
-            if (widget.onChanged != null) widget.onChanged(data);
+            widget.onChanged?.call(data);
           },
           maxChips: widget.maxChips,
           chipBuilder: widget.chipBuilder,

lib/src/fields/form_builder_color_picker.dart

@@ -222,7 +222,7 @@ class _FormBuilderColorPickerState extends State<FormBuilderColorPicker> {
 
   void _setColor(Color color) {
     _fieldKey.currentState.didChange(color);
-    if (widget.onChanged != null) widget.onChanged(color);
+    widget.onChanged?.call(color);
     _effectiveController.text = HexColor(color)?.toHex();
   }
 

lib/src/fields/form_builder_date_range_picker.dart

@@ -170,7 +170,7 @@ class FormBuilderDateRangePickerState
       text: _valueToText(),
     );
     _effectiveController.addListener(() {
-      if (widget.onChanged != null) widget.onChanged(_effectiveController.text);
+      widget.onChanged?.call(_effectiveController.text);
     });
     _focusNode = FocusNode();
     widget.focusNode?.addListener(_handleFocus);

lib/src/fields/form_builder_date_time_picker.dart

@@ -284,7 +284,7 @@ class _FormBuilderDateTimePickerState extends State<FormBuilderDateTimePicker> {
             FormBuilderValidators.validateValidators(val, widget.validators),
         onShowPicker: _onShowPicker,
         onChanged: (val) {
-          if (widget.onChanged != null) widget.onChanged(val);
+          widget.onChanged?.call(val);
         },
         autovalidate: widget.autovalidate,
         resetIcon: widget.resetIcon,

lib/src/fields/form_builder_dropdown.dart

@@ -179,7 +179,7 @@ class _FormBuilderDropdownState extends State<FormBuilderDropdown> {
           ? null
           : (value) {
         FocusScope.of(context).requestFocus(FocusNode());
-        if (widget.onChanged != null) widget.onChanged(value);
+        widget.onChanged?.call(value);
       },
       validator: (val) {
         for (int i = 0; i < widget.validators.length; i++) {

lib/src/fields/form_builder_radio.dart

@@ -73,7 +73,7 @@ class _FormBuilderRadioState extends State<FormBuilderRadio> {
           : (dynamic value) {
               FocusScope.of(context).requestFocus(FocusNode());
               field.didChange(value);
-              if (widget.onChanged != null) widget.onChanged(value);
+              widget.onChanged?.call(value);
             },
     );
   }

lib/src/fields/form_builder_radio_group.dart

@@ -104,7 +104,7 @@ class _FormBuilderRadioGroupState extends State<FormBuilderRadioGroup> {
                 : (value) {
                     FocusScope.of(context).requestFocus(FocusNode());
                     field.didChange(value);
-                    if (widget.onChanged != null) widget.onChanged(value);
+                    widget.onChanged?.call(value);
                   },
             items: widget.options
                 .map((option) => option.value)

lib/src/fields/form_builder_rate.dart

@@ -135,7 +135,7 @@ class _FormBuilderRateState extends State<FormBuilderRate> {
       onRatingChanged: (value) {
         FocusScope.of(context).requestFocus(FocusNode());
         field.didChange(value);
-        if (widget.onChanged != null) widget.onChanged(value);
+        widget.onChanged?.call(value);
         return value;
       },
     );