Add nullable property support to API modeling

Introduces IsNullable detection in ReflectionHelper and propagates it to PropertyApiDescriptionModel and TypeScript models. Updates logic to consider nullable properties when determining optionality, improving API schema accuracy for nullable reference types.

framework/src/Volo.Abp.Core/Volo/Abp/Reflection/ReflectionHelper.cs

@@ -8,6 +8,26 @@ namespace Volo.Abp.Reflection;
 //TODO: Consider to make internal
 public static class ReflectionHelper
 {
+    /// <summary>
+    /// Checks whether the property is nullable, including nullable reference types (NRT).
+    /// </summary>
+    /// <param name="propertyInfo">Property info to check</param>
+    public static bool IsNullable(PropertyInfo propertyInfo)
+    {
+        if (propertyInfo.PropertyType.IsValueType)
+        {
+            return false;
+        }
+
+#if NET6_0_OR_GREATER
+        var nullabilityInfoContext = new System.Reflection.NullabilityInfoContext();
+        var nullabilityInfo = nullabilityInfoContext.Create(propertyInfo);
+        return nullabilityInfo.ReadState == System.Reflection.NullabilityState.Nullable;
+#else
+        return false;
+#endif
+    }
+
     //TODO: Ehhance summary
     /// <summary>
     /// Checks whether <paramref name="givenType"/> implements/inherits <paramref name="genericType"/>.

framework/src/Volo.Abp.Http/Volo/Abp/Http/Modeling/PropertyApiDescriptionModel.cs

@@ -29,6 +29,8 @@ public class PropertyApiDescriptionModel
 
     public string? Regex { get; set; }
 
+    public bool IsNullable { get; set; }
+
     public static PropertyApiDescriptionModel Create(PropertyInfo propertyInfo)
     {
         var customAttributes = propertyInfo.GetCustomAttributes(true);
@@ -39,6 +41,7 @@ public class PropertyApiDescriptionModel
             Type = ApiTypeNameHelper.GetTypeName(propertyInfo.PropertyType),
             TypeSimple = ApiTypeNameHelper.GetSimpleTypeName(propertyInfo.PropertyType),
             IsRequired = customAttributes.OfType<RequiredAttribute>().Any() || propertyInfo.GetCustomAttributesData().Any(attr => attr.AttributeType.Name == "RequiredMemberAttribute"),
+            IsNullable = Volo.Abp.Reflection.ReflectionHelper.IsNullable(propertyInfo),
             Minimum = customAttributes.OfType<RangeAttribute>().Select(x => x.Minimum).FirstOrDefault()?.ToString(),
             Maximum = customAttributes.OfType<RangeAttribute>().Select(x => x.Maximum).FirstOrDefault()?.ToString(),
             MinLength = customAttributes.OfType<MinLengthAttribute>().FirstOrDefault()?.Length ?? customAttributes.OfType<StringLengthAttribute>().FirstOrDefault()?.MinimumLength,

npm/ng-packs/packages/schematics/src/models/api-definition.ts

@@ -20,6 +20,7 @@ export interface PropertyDef {
   type: string;
   typeSimple: string;
   isRequired: boolean;
+  isNullable: boolean;
 }
 
 export interface Module {

npm/ng-packs/packages/schematics/src/utils/model.ts

@@ -187,6 +187,7 @@ export function createRefToImportReducerCreator(params: ModelGeneratorParams) {
 
 function isOptionalProperty(prop: PropertyDef) {
   return (
+    prop.isNullable ||
     prop.typeSimple.endsWith('?') ||
     ((prop.typeSimple === 'string' || prop.typeSimple.includes('enum')) && !prop.isRequired)
   );