Added a copy button to modal window for easier bug fixing

XSDVisualiser.Desktop/Views/LeftTreeView.axaml.cs

@@ -186,13 +186,40 @@ public partial class LeftTreeView : UserControl
         // Compose content
         if (dialog.Content is Grid grid)
         {
-            var textBlock = new TextBlock
+            // Use a read-only TextBox so users can select text easily
+            var textBox = new TextBox
             {
                 Text = text,
+                IsReadOnly = true,
+                AcceptsReturn = true,
                 TextWrapping = Avalonia.Media.TextWrapping.Wrap,
                 Margin = new Thickness(12)
             };
-            var scroller = new ScrollViewer { Content = textBlock };
+
+            var scroller = new ScrollViewer { Content = textBox };
+
+            // Copy button
+            var copyButton = new Button
+            {
+                Content = "Copy",
+                MinWidth = 80,
+                HorizontalAlignment = HorizontalAlignment.Right,
+                Margin = new Thickness(8)
+            };
+            copyButton.Click += async (_, _) =>
+            {
+                var topLevel = TopLevel.GetTopLevel(this);
+                if (topLevel?.Clipboard != null)
+                {
+                    await topLevel.Clipboard.SetTextAsync(text);
+                    // Provide lightweight feedback by changing content briefly
+                    if (copyButton.Content is string)
+                        copyButton.Content = "Copied";
+                    await Task.Delay(1000);
+                    if (copyButton.Content is string)
+                        copyButton.Content = "Copy";
+                }
+            };
 
             var closeButton = new Button
             {
@@ -208,6 +235,7 @@ public partial class LeftTreeView : UserControl
                 Orientation = Orientation.Horizontal,
                 HorizontalAlignment = HorizontalAlignment.Right
             };
+            buttonsPanel.Children.Add(copyButton);
             buttonsPanel.Children.Add(closeButton);
 
             Grid.SetRow(buttonsPanel, 1);

XSDVisualiser/Utils/XmlValidation.cs

@@ -18,15 +18,7 @@ public static class XmlValidator
     {
         var result = new XmlValidationResult();
 
-        // Ensure the requested element exists in the schema set
+        // Probe XML root element first, we may use its namespace as a hint
-        var qname = new XmlQualifiedName(elementName, elementNamespace ?? string.Empty);
-        if (schemas.GlobalElements[qname] is not XmlSchemaElement)
-        {
-            result.AddError($"Element '{qname}' was not found in the compiled schema set.");
-            return result;
-        }
-
-        // Probe XML root element
         (string localName, string nsUri)? rootInfo = TryReadRoot(xmlPath);
         if (rootInfo is null)
         {
@@ -35,6 +27,42 @@ public static class XmlValidator
         }
 
         var (rootLocal, rootNs) = rootInfo.Value;
+
+        // Try to ensure the requested element exists in the schema set; if not, try to infer the correct namespace instead of failing hard.
+        var qname = new XmlQualifiedName(elementName, elementNamespace ?? string.Empty);
+        if (schemas.GlobalElements[qname] is not XmlSchemaElement)
+        {
+            // Try to find candidates with the same local name across namespaces
+            var candidates = schemas.GlobalElements.Names.Cast<XmlQualifiedName>().Where(n => string.Equals(n.Name, elementName, StringComparison.Ordinal)).Distinct().ToList();
+            if (candidates.Count == 1)
+            {
+                elementNamespace = candidates[0].Namespace;
+                qname = new XmlQualifiedName(elementName, elementNamespace ?? string.Empty);
+                result.AddWarning($"Element '{{{qname.Namespace}}}{qname.Name}' was not found with the provided namespace. Using detected namespace '{candidates[0].Namespace}'.");
+            }
+            else if (candidates.Count > 1)
+            {
+                // Prefer a candidate matching the XML root namespace if any
+                var preferred = candidates.FirstOrDefault(c => string.Equals(c.Namespace ?? string.Empty, rootNs ?? string.Empty, StringComparison.Ordinal));
+                if (preferred != null)
+                {
+                    elementNamespace = preferred.Namespace;
+                    qname = new XmlQualifiedName(elementName, elementNamespace ?? string.Empty);
+                    result.AddWarning($"Element namespace adjusted to match XML root namespace: '{{{preferred.Namespace}}}{preferred.Name}'.");
+                }
+                else
+                {
+                    var list = string.Join(", ", candidates.Select(c => $"'{{{c.Namespace}}}{c.Name}'"));
+                    result.AddWarning($"Element '{{{qname.Namespace}}}{qname.Name}' was not found in the compiled schema set. Candidates by name: {list}. Proceeding with best-effort validation.");
+                }
+            }
+            else
+            {
+                // No candidates at all; continue and let the validator report more actionable errors.
+                result.AddWarning($"Element '{{{qname.Namespace}}}{qname.Name}' was not found in the compiled schema set. Proceeding with best-effort validation.");
+            }
+        }
+
         var matchesRoot = string.Equals(rootLocal, elementName, StringComparison.Ordinal) && string.Equals(rootNs ?? string.Empty, elementNamespace ?? string.Empty, StringComparison.Ordinal);
 
         var settings = new XmlReaderSettings
@@ -99,8 +127,18 @@ public static class XmlValidator
 
                 if (elementNode is null)
                 {
-                    result.AddError($"Could not find any element '{{{elementNamespace}}}{elementName}' in the XML document to validate against.");
+                    // Try again ignoring namespace, in case the provided namespace was incorrect or omitted
-                    return result;
+                    var retry = FindFirstElementNode(xmlPath, elementName, null).Node;
+                    if (retry is not null)
+                    {
+                        result.AddWarning($"Could not find element '{{{elementNamespace}}}{elementName}' with the specified namespace; validating first occurrence by local name only.");
+                        elementNode = retry;
+                    }
+                    else
+                    {
+                        result.AddError($"Could not find any element '{{{elementNamespace}}}{elementName}' in the XML document to validate against.");
+                        return result;
+                    }
                 }
 
                 // Inform as a warning that we validate a subtree instead of the document root