Generate odata.nextLink and odata.deltaLink properties on delta functions response schemas

src/Microsoft.OpenApi.OData.Reader/Common/Constants.cs

@@ -115,6 +115,11 @@ internal static class Constants
         /// </summary>
         public static string BaseCollectionPaginationCountResponse = "BaseCollectionPaginationCountResponse";
 
+        /// <summary>
+        /// Suffix used for the base delta function response schemas.
+        /// </summary>
+        public static string BaseDeltaFunctionResponse = "BaseDeltaFunctionResponse";
+
         /// <summary>
         /// Name used for reference update.
         /// </summary>

src/Microsoft.OpenApi.OData.Reader/Edm/EdmOperationExtensions.cs

@@ -0,0 +1,22 @@
+using Microsoft.OData.Edm;
+
+namespace Microsoft.OpenApi.OData.Edm
+{
+    /// <summary>
+    /// Extension methods for <see cref="IEdmOperation"/>
+    /// </summary>
+    internal static class EdmOperationExtensions
+    {
+        /// <summary>
+        /// Checks whether the EDM is a delta function
+        /// </summary>
+        /// <param name="operation">The EDM operation.</param>
+        /// <returns></returns>
+        public static bool IsDeltaFunction(this IEdmOperation operation)
+        {
+            if (operation.IsFunction() && operation.Name == "delta")
+                return true;
+            return false;
+        }
+    }
+}

src/Microsoft.OpenApi.OData.Reader/Edm/EdmTypeExtensions.cs

@@ -13,7 +13,7 @@ namespace Microsoft.OpenApi.OData.Edm
     public static class EdmTypeExtensions
     {
         /// <summary>
-        /// Determines wether a path parameter should be wrapped in quotes based on the type of the parameter.
+        /// Determines whether a path parameter should be wrapped in quotes based on the type of the parameter.
         /// </summary>
         /// <param name="edmType">The type of the parameter.</param>
         /// <param name="settings">The conversion settings.</param>

src/Microsoft.OpenApi.OData.Reader/Generator/OpenApiResponseGenerator.cs

@@ -191,18 +191,60 @@ public static OpenApiResponse CreateOperationResponse(this ODataContext context,
             OpenApiSchema schema;
             if (operation.ReturnType.IsCollection())
             {
-                schema = new OpenApiSchema
+                OpenApiSchema baseSchema = new()
                 {
-                    Title = operation.ReturnType.Definition.AsElementType() is not IEdmEntityType entityType 
-                        ? null : $"Collection of {entityType.Name}",
-                    Type = "object",
+                    Type = Constants.ObjectType,
                     Properties = new Dictionary<string, OpenApiSchema>
                     {
                         {
                             "value", context.CreateEdmTypeSchema(operation.ReturnType)
                         }
                     }
                 };
+
+                if (context.Settings.EnableODataAnnotationReferencesForResponses && 
+                    (operation.IsDeltaFunction() || context.Settings.EnablePagination || context.Settings.EnableCount))
+                {
+                    schema = new OpenApiSchema
+                    {
+                        AllOf = new List<OpenApiSchema>
+                        {
+                            new OpenApiSchema
+                            {
+                                UnresolvedReference = true,
+                                Reference = new OpenApiReference
+                                {
+                                    Type = ReferenceType.Schema,
+                                    Id = operation.IsDeltaFunction() ? Constants.BaseDeltaFunctionResponse  // @odata.nextLink + @odata.deltaLink
+                                        : Constants.BaseCollectionPaginationCountResponse // @odata.nextLink + @odata.count
+                                }
+                            },
+                            baseSchema
+                        }
+                    };
+                }
+                else if (operation.IsDeltaFunction())
+                {
+                    baseSchema.Properties.Add(ODataConstants.OdataNextLink);
+                    baseSchema.Properties.Add(ODataConstants.OdataDeltaLink);
+                    schema = baseSchema;
+                }
+                else
+                {
+                    if (context.Settings.EnablePagination)
+                    {
+                        baseSchema.Properties.Add(ODataConstants.OdataNextLink);
+                    }
+                    if (context.Settings.EnableCount)
+                    {
+                        baseSchema.Properties.Add(ODataConstants.OdataCount);
+                    }
+                    schema = baseSchema;
+                }
+
+                schema.Title = operation.ReturnType.Definition.AsElementType() is not IEdmEntityType entityType
+                        ? null : $"Collection of {entityType.Name}";
+                schema.Type = "object";             
             }
             else if (operation.ReturnType.IsPrimitive())
             {

src/Microsoft.OpenApi.OData.Reader/Generator/OpenApiSchemaGenerator.cs

@@ -129,20 +129,34 @@ public static IDictionary<string, OpenApiSchema> CreateSchemas(this ODataContext
                 }
             };
 
-            // @odata.nextLink + @odata.count
-            if ((context.Settings.EnablePagination || context.Settings.EnableCount) &&
-                context.Settings.RefBaseCollectionPaginationCountResponse)
+            if (context.Settings.EnableODataAnnotationReferencesForResponses)
             {
-                schemas[Constants.BaseCollectionPaginationCountResponse] = new()
+                // @odata.nextLink + @odata.count
+                if (context.Settings.EnablePagination || context.Settings.EnableCount)
                 {
-                    Title = "Base collection pagination and count responses",
-                    Type = Constants.ObjectType,                   
-                };
+                    schemas[Constants.BaseCollectionPaginationCountResponse] = new()
+                    {
+                        Title = "Base collection pagination and count responses",
+                        Type = Constants.ObjectType,
+                    };
 
-                if (context.Settings.EnableCount)
-                    schemas[Constants.BaseCollectionPaginationCountResponse].Properties.Add(ODataConstants.OdataCount);
-                if (context.Settings.EnablePagination)
-                    schemas[Constants.BaseCollectionPaginationCountResponse].Properties.Add(ODataConstants.OdataNextLink);
+                    if (context.Settings.EnableCount)
+                        schemas[Constants.BaseCollectionPaginationCountResponse].Properties.Add(ODataConstants.OdataCount);
+                    if (context.Settings.EnablePagination)
+                        schemas[Constants.BaseCollectionPaginationCountResponse].Properties.Add(ODataConstants.OdataNextLink);
+                }
+
+                // @odata.nextLink + @odata.deltaLink
+                if (context.Model.SchemaElements.OfType<IEdmFunction>().Any(x => x.IsDeltaFunction()))
+                {
+                    schemas[Constants.BaseDeltaFunctionResponse] = new()
+                    {
+                        Title = "Base delta function response",
+                        Type = Constants.ObjectType
+                    };
+                    schemas[Constants.BaseDeltaFunctionResponse].Properties.Add(ODataConstants.OdataNextLink);
+                    schemas[Constants.BaseDeltaFunctionResponse].Properties.Add(ODataConstants.OdataDeltaLink);
+                }
             }
 
             return schemas;
@@ -232,10 +246,10 @@ private static OpenApiSchema CreateCollectionSchema(ODataContext context, OpenAp
                 Properties = properties
             };
 
-            OpenApiSchema colSchema;
+            OpenApiSchema collectionSchema;
             if (context.Settings.EnablePagination || context.Settings.EnableCount)
             {
-                if (context.Settings.RefBaseCollectionPaginationCountResponse)
+                if (context.Settings.EnableODataAnnotationReferencesForResponses)
                 {
                     // @odata.nextLink + @odata.count
                     OpenApiSchema paginationCountSchema = new()
@@ -248,7 +262,7 @@ private static OpenApiSchema CreateCollectionSchema(ODataContext context, OpenAp
                         }
                     };
 
-                    colSchema = new OpenApiSchema
+                    collectionSchema = new OpenApiSchema
                     {
                         AllOf = new List<OpenApiSchema>
                         {
@@ -265,17 +279,17 @@ private static OpenApiSchema CreateCollectionSchema(ODataContext context, OpenAp
                     if (context.Settings.EnableCount)
                         baseSchema.Properties.Add(ODataConstants.OdataCount);
 
-                    colSchema = baseSchema;
+                    collectionSchema = baseSchema;
                 }               
             }
             else
             {
-                colSchema = baseSchema;
+                collectionSchema = baseSchema;
             }
 
-            colSchema.Title = $"Collection of {typeName}";
-            colSchema.Type = Constants.ObjectType;
-            return colSchema;
+            collectionSchema.Title = $"Collection of {typeName}";
+            collectionSchema.Type = Constants.ObjectType;
+            return collectionSchema;
         }
 
         /// <summary>

src/Microsoft.OpenApi.OData.Reader/Microsoft.OpenAPI.OData.Reader.csproj

@@ -15,7 +15,7 @@
     <TargetFrameworks>netstandard2.0</TargetFrameworks>
     <PackageId>Microsoft.OpenApi.OData</PackageId>
     <SignAssembly>true</SignAssembly>
-    <Version>1.2.0-preview3</Version>
+    <Version>1.2.0-preview4</Version>
     <Description>This package contains the codes you need to convert OData CSDL to Open API Document of Model.</Description>
     <Copyright>© Microsoft Corporation. All rights reserved.</Copyright>
     <PackageTags>Microsoft OpenApi OData EDM</PackageTags>
@@ -26,6 +26,7 @@
 - Set assembly version used for conversion in OpenApiInfo object #208
 - Add support for alternate keys parameters #120
 - Adds create and update operations to non-containment navigation properties when restrictions annotations are explicitly set to true #265
+- Generate odata.nextLink and odata.deltaLink properties on delta functions response schemas #285
     </PackageReleaseNotes>
     <AssemblyName>Microsoft.OpenApi.OData.Reader</AssemblyName>
     <AssemblyOriginatorKeyFile>..\..\tool\Microsoft.OpenApi.OData.snk</AssemblyOriginatorKeyFile>

src/Microsoft.OpenApi.OData.Reader/OData/ODataConstants.cs

@@ -30,6 +30,10 @@ internal static class ODataConstants
         /// @odata.count KeyValue pair
         /// </summary>
         public static KeyValuePair<string, OpenApiSchema> OdataCount = new("@odata.count", new OpenApiSchema { Type = "integer", Format = "int64", Nullable = true });
-
+
+        /// <summary>
+        /// @odata.deltaLink KeyValue pair
+        /// </summary>
+        public static KeyValuePair<string, OpenApiSchema> OdataDeltaLink = new("@odata.deltaLink", new OpenApiSchema { Type = Constants.StringType, Nullable = true });
     }
 }

src/Microsoft.OpenApi.OData.Reader/OpenApiConvertSettings.cs

@@ -17,6 +17,8 @@ namespace Microsoft.OpenApi.OData
     /// </summary>
     public class OpenApiConvertSettings
     {
+        private bool _enableODataAnnotationReferencesForResponses = true;
+
         /// <summary>
         /// Gets/sets the service root.
         /// </summary>
@@ -108,8 +110,19 @@ public class OpenApiConvertSettings
         /// <summary>
         /// Gets/sets a value indicating whether or not to reference @odata.nextLink and @odata.count in responses
         /// </summary>
+        [Obsolete("Deprecated in favor of EnableODataAnnotationReferencesForResponses. " +
+            "When both are provided, EnableODataAnnotationReferencesForResponses takes precedence.")]
         public bool RefBaseCollectionPaginationCountResponse { get; set; } = true;
 
+        /// <summary>
+        /// Gets/sets a value indicating whether or not to reference @odata.nextLink, @odata.deltaLink and @odata.count in responses
+        /// </summary>
+        public bool EnableODataAnnotationReferencesForResponses 
+        {
+            get => _enableODataAnnotationReferencesForResponses;
+            set => _enableODataAnnotationReferencesForResponses = value && this.RefBaseCollectionPaginationCountResponse;
+        }
+
         /// <summary>
         /// Gets/sets a value that specifies the name of the operation for retrieving the next page in a collection of entities.
         /// </summary>
@@ -342,6 +355,7 @@ internal OpenApiConvertSettings Clone()
                 UseSuccessStatusCodeRange = this.UseSuccessStatusCodeRange,
                 EnableCount = this.EnableCount,
                 IncludeAssemblyInfo = this.IncludeAssemblyInfo,
+                EnableODataAnnotationReferencesForResponses = this.EnableODataAnnotationReferencesForResponses,
                 RefBaseCollectionPaginationCountResponse = this.RefBaseCollectionPaginationCountResponse
             };
 

src/Microsoft.OpenApi.OData.Reader/Operation/EdmActionOperationHandler.cs

@@ -64,16 +64,6 @@ protected override void SetRequestBody(OpenApiOperation operation)
         protected override void SetExtensions(OpenApiOperation operation)
         {
             operation.Extensions.Add(Constants.xMsDosOperationType, new OpenApiString("action"));
-            if (Context.Settings.EnablePagination && EdmOperation.ReturnType?.TypeKind() == EdmTypeKind.Collection)
-            {
-                OpenApiObject extension = new OpenApiObject
-                {
-                    { "nextLinkName", new OpenApiString("@odata.nextLink")},
-                    { "operationName", new OpenApiString(Context.Settings.PageableOperationName)}
-                };
-
-                operation.Extensions.Add(Constants.xMsPageable, extension);              
-            }
             base.SetExtensions(operation);
         }
     }

src/Microsoft.OpenApi.OData.Reader/Operation/EdmFunctionOperationHandler.cs

@@ -42,16 +42,6 @@ protected override void SetBasicInfo(OpenApiOperation operation)
         protected override void SetExtensions(OpenApiOperation operation)
         {
             operation.Extensions.Add(Constants.xMsDosOperationType, new OpenApiString("function"));
-            if (Context.Settings.EnablePagination && EdmOperation.ReturnType?.TypeKind() == EdmTypeKind.Collection)
-            {
-                OpenApiObject extension = new OpenApiObject
-                {
-                    { "nextLinkName", new OpenApiString("@odata.nextLink")},
-                    { "operationName", new OpenApiString(Context.Settings.PageableOperationName)}
-                };
-
-                operation.Extensions.Add(Constants.xMsPageable, extension);
-            }
             base.SetExtensions(operation);
         }
     }

src/Microsoft.OpenApi.OData.Reader/Operation/EdmOperationOperationHandler.cs

@@ -6,7 +6,6 @@
 using System.Collections.Generic;
 using System.Linq;
 using Microsoft.OData.Edm;
-using Microsoft.OData.Edm.Vocabularies;
 using Microsoft.OpenApi.Any;
 using Microsoft.OpenApi.Models;
 using Microsoft.OpenApi.OData.Common;
@@ -165,7 +164,7 @@ protected override void SetParameters(OpenApiOperation operation)
         }
 
         /// <inheritdoc/>
-        protected override void SetResponses(OpenApiOperation operation)
+        protected override void SetResponses(OpenApiOperation operation) 
         {
             operation.Responses = Context.CreateResponses(EdmOperation);
             base.SetResponses(operation);
@@ -277,5 +276,21 @@ protected override void SetExternalDocs(OpenApiOperation operation)
                 };
             }
         }
+
+        // <inheritdoc/>
+        protected override void SetExtensions(OpenApiOperation operation)
+        {
+            if (Context.Settings.EnablePagination && EdmOperation.ReturnType?.TypeKind() == EdmTypeKind.Collection)
+            {
+                OpenApiObject extension = new OpenApiObject
+                {
+                    { "nextLinkName", new OpenApiString("@odata.nextLink")},
+                    { "operationName", new OpenApiString(Context.Settings.PageableOperationName)}
+                };
+
+                operation.Extensions.Add(Constants.xMsPageable, extension);
+            }
+            base.SetExtensions(operation);
+        }
     }
 }

src/Microsoft.OpenApi.OData.Reader/PublicAPI.Unshipped.txt

@@ -11,6 +11,8 @@ Microsoft.OpenApi.OData.OpenApiConvertSettings.CustomHttpMethodLinkRelMapping.ge
 Microsoft.OpenApi.OData.OpenApiConvertSettings.CustomHttpMethodLinkRelMapping.set -> void
 Microsoft.OpenApi.OData.OpenApiConvertSettings.EnableCount.get -> bool
 Microsoft.OpenApi.OData.OpenApiConvertSettings.EnableCount.set -> void
+Microsoft.OpenApi.OData.OpenApiConvertSettings.EnableODataAnnotationReferencesForResponses.get -> bool
+Microsoft.OpenApi.OData.OpenApiConvertSettings.EnableODataAnnotationReferencesForResponses.set -> void
 Microsoft.OpenApi.OData.OpenApiConvertSettings.ExpandDerivedTypesNavigationProperties.get -> bool
 Microsoft.OpenApi.OData.OpenApiConvertSettings.ExpandDerivedTypesNavigationProperties.set -> void
 Microsoft.OpenApi.OData.OpenApiConvertSettings.CustomXMLAttributesMapping.get -> System.Collections.Generic.Dictionary<string, string>