Add OpenXmlElement.IsValidChild method

src/DocumentFormat.OpenXml.Framework/OpenXmlElement.cs

@@ -1330,6 +1330,21 @@ public bool IsBefore(OpenXmlElement element)
             return GetOrder(this, element) == ElementOrder.Before;
         }
 
+        /// <summary>
+        /// Determines if the specified element is a valid child of the current element.
+        /// </summary>
+        /// <param name="element">The element to check.</param>
+        /// <returns>True if the specified element is a valid child; otherwise, false.</returns>
+        public bool IsValidChild(OpenXmlElement element)
+        {
+            if (element is null)
+            {
+                throw new ArgumentNullException(nameof(element));
+            }
+
+            return Metadata.Children.Elements.Any(el => el.Type.Name.Equals(element.Metadata.Type.Name));
+        }
+
         private enum ElementOrder
         {
             Same, // same element

src/DocumentFormat.OpenXml.Framework/PublicAPI/PublicAPI.Shipped.txt

@@ -1009,3 +1009,4 @@ DocumentFormat.OpenXml.OpenXmlPartWriterSettings.Encoding.set -> void
 DocumentFormat.OpenXml.OpenXmlPartWriterSettings.OpenXmlPartWriterSettings() -> void
 DocumentFormat.OpenXml.OpenXmlPartWriter.OpenXmlPartWriter(DocumentFormat.OpenXml.Packaging.OpenXmlPart! openXmlPart, DocumentFormat.OpenXml.OpenXmlPartWriterSettings! settings) -> void
 DocumentFormat.OpenXml.OpenXmlPartWriter.OpenXmlPartWriter(System.IO.Stream! partStream, DocumentFormat.OpenXml.OpenXmlPartWriterSettings! settings) -> void
+DocumentFormat.OpenXml.OpenXmlElement.IsValidChild(DocumentFormat.OpenXml.OpenXmlElement! element) -> bool

test/DocumentFormat.OpenXml.Tests/ofapiTest/OpenXmlElementTest2.cs

@@ -240,5 +240,43 @@ public void GetOrAddFirstChildTest()
             var r2 = p.GetOrAddFirstChild<Run>();
             Assert.Same(r, r2);
         }
+
+        [Fact]
+        public void IsValidChild_ValidChild_ReturnsTrue()
+        {
+            // Arrange
+            var parentElement = new Paragraph();
+            var validChild = new Run();
+
+            // Act
+            var result = parentElement.IsValidChild(validChild);
+
+            // Assert
+            Assert.True(result);
+        }
+
+        [Fact]
+        public void IsValidChild_InvalidChild_ReturnsFalse()
+        {
+            // Arrange
+            var parentElement = new Paragraph();
+            var invalidChild = new Table();
+
+            // Act
+            var result = parentElement.IsValidChild(invalidChild);
+
+            // Assert
+            Assert.False(result);
+        }
+
+        [Fact]
+        public void IsValidChild_NullChild_ThrowsArgumentNullException()
+        {
+            // Arrange
+            var parentElement = new Paragraph();
+
+            // Act & Assert
+            Assert.Throws<ArgumentNullException>(() => parentElement.IsValidChild(null));
+        }
     }
 }