feat: set & get validation

CarManagerV3/CarDetailsForm.cs

@@ -29,34 +29,85 @@ namespace CarManagerV3
             lblID.Text = $"ID: {car.Id}";
         }
 
+        /// <summary>
+        /// Updates a car property safely by executing the update action and reverting it if an exception occurs.
+        /// </summary>
+        /// <param name="updateAction">The update action.</param>
+        /// <param name="revertAction">The action to perform when the update fails.</param>
+        private void SafeUpdate(Action updateAction, Action revertAction)
+        {
+            try
+            {
+                updateAction();
+            }
+            catch (ArgumentException ex)
+            {
+                MessageBox.Show(ex.Message, "Invalid Input", MessageBoxButtons.OK, MessageBoxIcon.Error);
+                revertAction();
+            }
+        }
+
+        //private string ValueOrFormer(string newValue, string oldValue)
+        //{
+        //    return string.IsNullOrWhiteSpace(newValue) ? oldValue : newValue;
+        //}
+
+        private T ValueOrFormer<T>(T newValue, T oldValue)
+        {
+            if (newValue is string str)
+            {
+                return string.IsNullOrWhiteSpace(str) ? oldValue : newValue;
+            }
+            return newValue;
+        }
+
         private void tbxMake_TextChanged(object sender, EventArgs e)
         {
-            car.Make = tbxMake.Text;
+            SafeUpdate(
+                () => car.Make = ValueOrFormer(tbxMake.Text, car.Make),
+                () => tbxMake.Text = car.Make
+            );
         }
 
         private void tbxModel_TextChanged(object sender, EventArgs e)
         {
-            car.Model = tbxModel.Text;
+            SafeUpdate(
+                () => car.Model = ValueOrFormer(tbxModel.Text, car.Model),
+                () => tbxModel.Text = car.Model
+            );
         }
 
         private void nudYear_ValueChanged(object sender, EventArgs e)
         {
-            car.Year = (int)nudYear.Value;
+            Console.WriteLine("Year value changed: " + nudYear.Value);
+            SafeUpdate(
+                () => car.Year = (int)ValueOrFormer(nudYear.Value, car.Year),
+                () => nudYear.Value = car.Year
+            );
         }
 
         private void tbxColor_TextChanged(object sender, EventArgs e)
         {
-            car.Color = tbxColor.Text;
+            SafeUpdate(
+                () => car.Color = ValueOrFormer(tbxColor.Text, car.Color),
+                () => tbxColor.Text = car.Color
+            );
         }
 
         private void nudMileage_ValueChanged(object sender, EventArgs e)
         {
-            car.Mileage = (int)nudMileage.Value;
+            SafeUpdate(
+                () => car.Mileage = (int)nudMileage.Value, 
+                () => nudMileage.Value = car.Mileage
+            );
         }
 
         private void nudPrice_ValueChanged(object sender, EventArgs e)
         {
-            car.Price = nudPrice.Value;
+            SafeUpdate(
+                () => car.Price = nudPrice.Value, 
+                () => nudPrice.Value = car.Price
+            );
         }
 
         private async void btnSave_Click(object sender, EventArgs e)
@@ -113,5 +164,22 @@ namespace CarManagerV3
             }
             return base.ProcessCmdKey(ref msg, keyData);
         }
+
+        private void tbxMake_Leave(object sender, EventArgs e)
+        {
+            tbxMake.Text = ValueOrFormer(tbxMake.Text, car.Make);
+        }
+
+        private void tbxModel_Leave(object sender, EventArgs e)
+        {
+            tbxModel.Text = ValueOrFormer(tbxModel.Text, car.Model);
+        }
+
+        private void tbxColor_Leave(object sender, EventArgs e)
+        {
+            tbxColor.Text = ValueOrFormer(tbxColor.Text, car.Color);
+        }
+
+
     }
 }