Feature: Validate if folder exists for the export (#1760)

* Feature: Validate if folder exists for the export

* Docs: Add #1760

Author: BornToBeRoot

Source/NETworkManager.Validators/FolderInPathExistsValidator.cs

@@ -0,0 +1,29 @@
+using System.Globalization;
+using System.IO;
+using System.Windows.Controls;
+using NETworkManager.Localization.Resources;
+
+namespace NETworkManager.Validators
+{
+    /// <summary>
+    /// Check if the folder in the full path exists on the system (like "C:\Temp" from "C:\Temp\export.json").
+    /// </summary>
+    public class FolderInPathExistsValidator : ValidationRule
+    {
+        /// <summary>
+        /// Check if the string is a valid file path (like "C:\Temp\Test.txt"). The file path does not have to exist on the local system.
+        /// </summary>
+        /// <param name="value">File path like "C:\Temp\Test.txt"".</param>
+        /// <param name="cultureInfo">Culture to use for validation.</param>
+        /// <returns>True if the folder exists.</returns>
+        public override ValidationResult Validate(object value, CultureInfo cultureInfo)
+        {
+            string path = Path.GetDirectoryName((string)value);
+
+            if (Directory.Exists(path))
+                return ValidationResult.ValidResult;
+            else
+                return new ValidationResult(false, Strings.FolderDoesNotExist);
+        }
+    }
+}

Source/NETworkManager/Views/ExportDialog.xaml

@@ -61,6 +61,7 @@
                         <Binding.ValidationRules>
                             <validators:EmptyValidator ValidatesOnTargetUpdated="True" />
                             <validators:FilePathValidator ValidatesOnTargetUpdated="True" />
+                            <validators:FolderInPathExistsValidator ValidatesOnTargetUpdated="True" />
                         </Binding.ValidationRules>
                     </Binding>
                 </TextBox.Text>

docs/Changelog/next-release.md

@@ -27,6 +27,7 @@ New Feature
 - Performance of DNS resolutions improved [#1733](https://github.com/BornToBeRoot/NETworkManager/pull/1733){:target="\_blank"}
 - Detect new DNS servers if they have been changed e.g. by a new network connection (LAN, WLAN) or VPN connection [#1733](https://github.com/BornToBeRoot/NETworkManager/pull/1733){:target="\_blank"}
 - Error messages for failed DNS resolution improved [#1733](https://github.com/BornToBeRoot/NETworkManager/pull/1733){:target="\_blank"}
+- Check if folder exists in export dialog [#1760](https://github.com/BornToBeRoot/NETworkManager/pull/1760){:target="\_blank"}
 
 ## Bugfixes