Extension classes now inherit from ExtensionBase

Author: vpenades

src/SharpGLTF.CodeGen.Core/CodeGen/EmitCSharp.cs

@@ -44,7 +44,7 @@ public void SetRuntimeName(SchemaType stype, string runtimeName, string runtimeN
 
             t.RuntimeNamespace = runtimeNamespace;
             t.RuntimeName = runtimeName;
-        }
+        }        
 
         /// <summary>
         /// Gets the runtime name associated to the type with the given <paramref name="persistentName"/>
@@ -162,7 +162,7 @@ private _RuntimeType _UseType(SchemaType stype)
 
             rtype = new _RuntimeType()
             {
-                RuntimeName = _SanitizeName(stype.PersistentName)
+                RuntimeName = _SanitizeName(stype.PersistentName)                
             };
 
             _Types[key] = rtype;
@@ -451,7 +451,26 @@ private string _GetClassDeclaration(ClassType type)
             classDecl += "partial ";
             classDecl += "class ";
             classDecl += _GetRuntimeName(type);
-            if (type.BaseClass != null) classDecl += $" : {_GetRuntimeName(type.BaseClass)}";
+
+            if (type.BaseClass != null)
+            {
+                var baseClass = _GetRuntimeName(type.BaseClass);
+
+                // if type is an extension, replace ExtraProperties base class
+                // with the more meaningful ExtensionBase class
+                if (baseClass == "ExtraProperties" && type.PersistentName.EndsWith(" EXTENSION", StringComparison.OrdinalIgnoreCase))
+                {
+                    var parentIdentifier = type.Identifier.Split('.')[0];
+                    // parentIdentifier is glTF, material, node, etc
+                    // var parentClass = type._Owner.FindClass(parentIdentifier);
+                    // var parentName = _GetRuntimeName(parentClass);
+
+                    baseClass = "ExtensionBase";
+                }
+
+                classDecl += $" : {baseClass}";
+            }
+
             return classDecl;
         }
 

src/SharpGLTF.Core/Schema2/gltf.ExtensionsFactory.cs

@@ -80,38 +80,7 @@ static ExtensionsFactory()
 
         public static IEnumerable<string> SupportedExtensions => _Extensions
             .Select(item => item.Name)
-            .Concat(new[] { "KHR_mesh_quantization" }); // special case because it's a "typeless" extension.
-
-        /// <summary>
-        /// Registers a new extensions to be used globally.
-        /// </summary>
-        /// <typeparam name="TParent">The parent type to which this extension is attached.</typeparam>
-        /// <typeparam name="TExtension">The extension type.</typeparam>
-        /// <param name="persistentName">The extension name.</param>
-        /// <remarks>
-        /// The <paramref name="persistentName"/> is the value used for serialization<br/>
-        /// and it must meet <see href="https://github.com/KhronosGroup/glTF/blob/master/extensions/Prefixes.md">extension naming constraints</see>.
-        /// </remarks>
-        [Obsolete("Use RegisterExtension(name, factory) instead.")]
-        public static void RegisterExtension
-            <TParent,
-                #if NET6_0_OR_GREATER
-                [DYNAMICMEMBERS(DYNAMICCONSTRUCTORS)]
-                #endif
-            TExtension>
-            (string persistentName)
-            where TParent : JsonSerializable
-            where TExtension : JsonSerializable
-        {
-            Guard.NotNullOrEmpty(persistentName, nameof(persistentName));
-            Guard.MustBeNull(Identify(typeof(TParent), typeof(TExtension)), $"{nameof(TExtension)} already registered for {nameof(TParent)}");
-
-            // TODO: check that persistentName has a valid extension name.
-
-            var ext = ExtensionEntry.Create<TParent,TExtension>(persistentName);
-
-            _Extensions.Add(ext);
-        }
+            .Concat(new[] { "KHR_mesh_quantization" }); // special case because it's a "typeless" extension.        
 
         /// <summary>
         /// Registers a new extensions to be used globally.
@@ -126,7 +95,7 @@ public static void RegisterExtension
         /// </remarks>
         public static void RegisterExtension<TParent,TExtension>(string persistentName, Func<TParent, JsonSerializable> factory)
             where TParent : JsonSerializable
-            where TExtension : JsonSerializable
+            where TExtension : ExtensionBase
         {
             Guard.NotNullOrEmpty(persistentName, nameof(persistentName));
             Guard.MustBeNull(Identify(typeof(TParent), typeof(TExtension)), $"{nameof(TExtension)} already registered for {nameof(TParent)}");
@@ -299,13 +268,11 @@ internal void UpdateExtensionsSupport()
                     if (string.IsNullOrWhiteSpace(id)) continue;
 
                     bool isRequired = false;
-
-                    #pragma warning disable GLTF1001 // Type is for evaluation purposes only and is subject to change or removal in future updates. Suppress this diagnostic to proceed.
-                    if (ext is IExtensionTypeInfo extInfo)
+                    
+                    if (ext is ExtensionBase extInfo)
                     {
                         isRequired = extInfo.CheckIsRequiredExtension(c);
-                    }
-                    #pragma warning restore GLTF1001 // Type is for evaluation purposes only and is subject to change or removal in future updates. Suppress this diagnostic to proceed.
+                    }                    
 
                     if (exts.TryGetValue(id, out var stored)) { isRequired |= stored; }
 
@@ -344,21 +311,15 @@ internal void _ValidateExtensions(Validation.ValidationContext validate)
     }
 
     /// <summary>
-    /// Implemented by extensions
+    /// Base class for extensions
     /// </summary>
-    #if NET8_0_OR_GREATER
-    [Experimental("GLTF1001")] // I might move this functionality to an "ExtensionBase" class
-    #endif
-    public interface IExtensionTypeInfo
+    public abstract class ExtensionBase : ExtraProperties
     {
-        /// <summary>
-        /// Checks whether the extension instance implementing this interface should be tagged as required.
-        /// </summary>
-        /// <param name="extensionOwner">the owner of the extension</param>
-        /// <returns>true if the extension should be tagged as required</returns>
-        /// <remarks>
-        /// This is called just before saving the model.
-        /// </remarks>
-        public bool CheckIsRequiredExtension(ExtraProperties extensionOwner);
-    }
+        protected ExtensionBase() { }
+
+        public virtual bool CheckIsRequiredExtension(ExtraProperties extensionOwner)
+        {
+            return false;
+        }
+    }    
 }

src/SharpGLTF.Core/Schema2/gltf.Textures.cs

@@ -158,7 +158,7 @@ protected override void OnValidateReferences(ValidationContext validate)
 
     #pragma warning disable GLTF1001 // Type is for evaluation purposes only and is subject to change or removal in future updates. Suppress this diagnostic to proceed.
 
-    partial class TextureDDS : IExtensionTypeInfo
+    partial class TextureDDS
     {
         internal TextureDDS(Texture parent)
         {
@@ -182,15 +182,15 @@ public Image Image
             }
         }
 
-        public bool CheckIsRequiredExtension(ExtraProperties extensionOwner)
+        public override bool CheckIsRequiredExtension(ExtraProperties extensionOwner)
         {
             if (extensionOwner is not Texture tex) return false;
 
             return tex.FallbackImage == null;
         }
     }
 
-    partial class TextureWEBP : IExtensionTypeInfo
+    partial class TextureWEBP
     {
         internal TextureWEBP(Texture parent)
         {
@@ -214,15 +214,15 @@ public Image Image
             }
         }
 
-        public bool CheckIsRequiredExtension(ExtraProperties extensionOwner)
+        public override bool CheckIsRequiredExtension(ExtraProperties extensionOwner)
         {
             if (extensionOwner is not Texture tex) return false;
 
             return tex.FallbackImage == null;
         }
     }
 
-    partial class TextureKTX2 : IExtensionTypeInfo
+    partial class TextureKTX2
     {
         internal TextureKTX2(Texture parent)
         {
@@ -246,7 +246,7 @@ public Image Image
             }
         }
 
-        public bool CheckIsRequiredExtension(ExtraProperties extensionOwner)
+        public override bool CheckIsRequiredExtension(ExtraProperties extensionOwner)
         {
             if (extensionOwner is not Texture tex) return false;
 

tests/SharpGLTF.ThirdParty.Tests/GaussianSplatExtension.cs

@@ -37,7 +37,7 @@ public int BufferViewIndex
 	[System.Diagnostics.CodeAnalysis.DynamicallyAccessedMembers(System.Diagnostics.CodeAnalysis.DynamicallyAccessedMemberTypes.NonPublicConstructors | System.Diagnostics.CodeAnalysis.DynamicallyAccessedMemberTypes.PublicConstructors)]
 #endif
     [global::System.CodeDom.Compiler.GeneratedCodeAttribute("SharpGLTF.CodeGen", "1.0.0.0")]
-    partial class SpzGaussianSplatsCompression : ExtraProperties
+    partial class SpzGaussianSplatsCompression : ExtensionBase
     {
 
         #region reflection