handle paths and use caching when getting data type

akgulebubekir · Jan 1, 2024 · d9c50cc · d9c50cc
1 parent d9dd3c4
commit d9c50cc
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Showing 2 changed files with 74 additions and 11 deletions.
diff --git a/Maui.DataGrid/DataGridColumn.cs b/Maui.DataGrid/DataGridColumn.cs
@@ -363,20 +363,38 @@ public bool IsSortable()
 
     internal void InitializeDataType()
     {
+        if (DataType != null || string.IsNullOrEmpty(PropertyName))
+        {
+            return;
+        }
+
         ArgumentNullException.ThrowIfNull(DataGrid);
 
-        if (DataType == null && PropertyName != null)
+        try
         {
-            try
+            Type? rowDataType = null;
+
+            var genericArguments = DataGrid.ItemsSource.GetType().GetGenericArguments();
+
+            if (genericArguments.Length == 1)
             {
-                var rowDataType = DataGrid.ItemsSource.GetType().GetGenericArguments().Single();
-                DataType = rowDataType.GetProperty(PropertyName)?.PropertyType;
+                rowDataType = genericArguments[0];
             }
-            catch (Exception ex)
-                when (ex is NotSupportedException or ArgumentNullException or InvalidOperationException)
+            else
             {
-                Debug.WriteLine($"Initializing the data type for the column '{Title}' resulted in the following error: {ex.Message}");
+                var firstItem = DataGrid.ItemsSource.OfType<object>().FirstOrDefault(i => i != null);
+                if (firstItem != default)
+                {
+                    rowDataType = firstItem.GetType();
+                }
             }
+
+            DataType = rowDataType?.GetPropertyTypeByPath(PropertyName);
+        }
+        catch (Exception ex)
+            when (ex is NotSupportedException or ArgumentNullException or InvalidCastException)
+        {
+            Debug.WriteLine($"Attempting to obtain the data type for the column '{Title}' resulted in the following error: {ex.Message}");
         }
     }
 

diff --git a/Maui.DataGrid/Extensions/ReflectionExtensions.cs b/Maui.DataGrid/Extensions/ReflectionExtensions.cs
@@ -43,18 +43,63 @@ internal static class ReflectionExtensions
         return result;
     }
 
+    public static Type? GetPropertyTypeByPath(this Type type, string path)
+    {
+        if (type == null || string.IsNullOrWhiteSpace(path))
+        {
+            return null;
+        }
+
+        Type? resultType;
+
+        if (path.Contains(PropertyOfOp, StringComparison.Ordinal))
+        {
+            var tokens = path.Split(PropertyOfOp);
+
+            resultType = type;
+
+            foreach (var token in tokens)
+            {
+                resultType = resultType.GetPropertyType(token);
+
+                if (resultType == null)
+                {
+                    break;
+                }
+            }
+        }
+        else
+        {
+            resultType = type.GetPropertyType(path);
+        }
+
+        return resultType;
+    }
+
+    private static Type? GetPropertyType(this Type type, string propertyName)
+    {
+        var propertyDescriptor = GetPropertyDescriptor(type, propertyName);
+
+        return propertyDescriptor?.PropertyType;
+    }
+
     private static object? GetPropertyValue(object obj, string propertyName)
     {
         var type = obj.GetType();
 
+        var propertyDescriptor = GetPropertyDescriptor(type, propertyName);
+
+        return propertyDescriptor?.GetValue(obj);
+    }
+
+    private static PropertyDescriptor? GetPropertyDescriptor(Type type, string propertyName)
+    {
         if (!PropertyTypeCache.TryGetValue(type, out var properties))
         {
-            properties = TypeDescriptor.GetProperties(obj);
+            properties = TypeDescriptor.GetProperties(type);
             PropertyTypeCache[type] = properties;
         }
 
-        var propertyDescriptor = properties.Find(propertyName, false);
-
-        return propertyDescriptor?.GetValue(obj);
+        return properties.Find(propertyName, false);
     }
 }