clean code

lib/presentation/custom_widgets/widget_action_field_date.dart

 class _FieldDateWidgetState extends State<FieldDateWidget> {
   ChangeDateTimePicker controller;
   final textController = TextEditingController();
-  var isShowError = false;
 
   @override
   void initState() {
         builder: (data) {
           return SizedBox(
             width: double.infinity,
-            height: Validators.stringNotNullOrEmpty(textController.text) &&
-                    validators != null
-                ? 65
-                : widget.isValidated
-                    ? 85
-                    : 85,
+            height: isShowError() ? 85 : 65,
             child: Column(
               crossAxisAlignment: CrossAxisAlignment.start,
               children: [
-                Validators.stringNotNullOrEmpty(
-                        data?.selectedDateTime?.displayDateTime_DDMMYYYY_HHmm())
+                isShowError()
                     ? Text(
                         widget.hint ?? '',
-                        style: TextStyle(
-                            color: Validators.stringNotNullOrEmpty(
-                                        textController.text) &&
-                                    validators != null
-                                ? Colors.black54
-                                : Colors.red,
-                            fontSize: 13.0),
+                        style: TextStyle(color: Colors.red, fontSize: 13.0),
                       )
                     : Text(
                         '',
                                 border: Border(
                                     bottom: BorderSide(
                                   width: 0.5,
-                                  color: Validators.stringNotNullOrEmpty(
-                                              textController.text) &&
-                                          validators != null
-                                      ? Colors.black54
-                                      : widget.isValidated
-                                          ? Colors.red
-                                          : Colors.black54,
+                                  color: isShowError()
+                                      ? Colors.red
+                                      : Colors.black54,
                                 )),
                               ),
                               child: Row(
                         ],
                       )),
                 ),
-                Validators.stringNotNullOrEmpty(textController.text) &&
-                        validators != null
-                    ? SizedBox()
-                    : Text(
+                isShowError()
+                    ? Text(
                         widget.isValidated
                             ? 'Vui lòng nhập ${widget.hint}'
                             : '',
                             color: Colors.red,
                             fontWeight: FontWeight.normal),
                         textAlign: TextAlign.left,
-                      ),
+                      )
+                    : SizedBox(),
                 Container(
                   height: 0,
                   child: TextFormField(
           );
         });
   }
+
+  bool isShowError() {
+    if (widget.validator == null) {
+      return false;
+    } else {
+      if (widget.isValidated) {
+        return Validators.stringNotNullOrEmpty(textController.text)
+            ? false
+            : true;
+      } else {
+        return false;
+      }
+    }
+  }
 }