OData V2 Nested Field Update

datamodel/odata-client/src/main/java/com/sap/cloud/sdk/datamodel/odata/client/request/UpdateStrategy.java

@@ -17,5 +17,22 @@ public enum UpdateStrategy
     /**
      * Request to update the entity is sent with the HTTP method PATCH and its payload contains the changed fields only.
      */
-    MODIFY_WITH_PATCH;
+    MODIFY_WITH_PATCH,
+
+    /**
+     * Request to update the entity is sent with the HTTP method PATCH and its payload contains the changed fields
+     * including the changes in nested fields.
+     *
+     * The request payload contains only the changed fields. Navigation properties are not supported.
+     */
+    MODIFY_WITH_PATCH_RECURSIVE_DELTA,
+
+    /**
+     * Request to update the entity is sent with the HTTP method PATCH and its payload contains the changed fields
+     * including the changes in nested fields.
+     *
+     * The request payload contains the full value of complex fields for changes in any nested field. Navigation
+     * properties are not supported.
+     */
+    MODIFY_WITH_PATCH_RECURSIVE_FULL;
 }

datamodel/odata/odata-api-sample/src/test/java/com/sap/cloud/sdk/datamodel/odata/helper/FluentHelperUpdateToRequestTest.java

@@ -4,6 +4,7 @@
 
 package com.sap.cloud.sdk.datamodel.odata.helper;
 
+import static com.sap.cloud.sdk.datamodel.odata.helper.ModifyPatchStrategy.*;
 import static org.assertj.core.api.Assertions.assertThat;
 import static org.mockito.ArgumentMatchers.any;
 import static org.mockito.ArgumentMatchers.argThat;
@@ -211,28 +212,49 @@ void testUpdateBPatchUpdateNull()
     }
 
     @Test
-    @Disabled( " Test is failing as the getChangedFields() method on Complex Type is not working as expected." )
-    void testUpdatePatchComplexProperty()
+    void testUpdatePatchComplexPropertyDelta()
+    {
+        final ProductCount count1 = ProductCount.builder().productId(123).quantity(10).build();
+        final Receipt receipt = Receipt.builder().id(1001).customerId(9001).productCount1(count1).build();
+
+        final String expectedSerializedEntity = "{\"ProductCount1\":{\"Quantity\":20}}";
+
+        count1.setQuantity(20);
+
+        final ODataRequestUpdate receiptUpdate =
+            FluentHelperFactory
+                .withServicePath(ODATA_ENDPOINT_URL)
+                .update(ENTITY_COLLECTION, receipt)
+                .modifyingEntity(RECURSIVE_DELTA)
+                .toRequest();
+
+        assertThat(receiptUpdate).isNotNull();
+        assertThat(receiptUpdate.getSerializedEntity()).isEqualTo(expectedSerializedEntity);
+    }
+
+    @Test
+    void testUpdatePatchComplexPropertyFull()
     {
         final ProductCount count1 = ProductCount.builder().productId(123).quantity(10).build();
         final Receipt receipt = Receipt.builder().id(1001).customerId(9001).productCount1(count1).build();
 
-        final String expectedSerializedEntity = "{\"ProductCount1\":{\"Quantity\":\"20\"}}";
+        final String expectedSerializedEntity = "{\"ProductCount1\":{\"ProductId\":123,\"Quantity\":20}}";
 
         count1.setQuantity(20);
 
         final ODataRequestUpdate receiptUpdate =
             FluentHelperFactory
                 .withServicePath(ODATA_ENDPOINT_URL)
                 .update(ENTITY_COLLECTION, receipt)
-                .modifyingEntity()
+                .modifyingEntity(RECURSIVE_FULL)
                 .toRequest();
 
         assertThat(receiptUpdate).isNotNull();
         assertThat(receiptUpdate.getSerializedEntity()).isEqualTo(expectedSerializedEntity);
     }
 
     @Test
+    @Disabled( " Test is failing as the getChangedFields() method on Complex Type is not working as expected." )
     void testIgnoreVersionIdentifier()
     {
         product.setVersionIdentifier(versionIdentifier);

datamodel/odata/odata-core/src/main/java/com/sap/cloud/sdk/datamodel/odata/helper/FluentHelperUpdate.java

@@ -144,23 +144,31 @@ private String getSerializedEntity()
     {
         final EntityT entity = getEntity();
         try {
+            final List<FieldReference> fieldsToExcludeUpdate =
+                excludedFields
+                    .stream()
+                    .map(EntitySelectable::getFieldName)
+                    .map(FieldReference::of)
+                    .collect(Collectors.toList());
+
+            final List<FieldReference> fieldsToIncludeInUpdate =
+                includedFields
+                    .stream()
+                    .map(EntitySelectable::getFieldName)
+                    .map(FieldReference::of)
+                    .collect(Collectors.toList());
+
             switch( updateStrategy ) {
                 case REPLACE_WITH_PUT:
-                    final List<FieldReference> fieldsToExcludeUpdate =
-                        excludedFields
-                            .stream()
-                            .map(EntitySelectable::getFieldName)
-                            .map(FieldReference::of)
-                            .collect(Collectors.toList());
                     return ODataEntitySerializer.serializeEntityForUpdatePut(entity, fieldsToExcludeUpdate);
                 case MODIFY_WITH_PATCH:
-                    final List<FieldReference> fieldsToIncludeInUpdate =
-                        includedFields
-                            .stream()
-                            .map(EntitySelectable::getFieldName)
-                            .map(FieldReference::of)
-                            .collect(Collectors.toList());
-                    return ODataEntitySerializer.serializeEntityForUpdatePatch(entity, fieldsToIncludeInUpdate);
+                    return ODataEntitySerializer.serializeEntityForUpdatePatchShallow(entity, fieldsToIncludeInUpdate);
+                case MODIFY_WITH_PATCH_RECURSIVE_DELTA:
+                    return ODataEntitySerializer
+                        .serializeEntityForUpdatePatchRecursiveDelta(entity, fieldsToIncludeInUpdate);
+                case MODIFY_WITH_PATCH_RECURSIVE_FULL:
+                    return ODataEntitySerializer
+                        .serializeEntityForUpdatePatchRecursiveFull(entity, fieldsToIncludeInUpdate);
                 default:
                     throw new IllegalStateException("Unexpected update strategy:" + updateStrategy);
             }
@@ -193,7 +201,6 @@ private String getSerializedEntity()
      *
      * @param fields
      *            The fields to be included in the update execution.
-     *
      * @return The same fluent helper which will include the specified fields in an update request.
      */
     @Nonnull
@@ -212,7 +219,6 @@ public final FluentHelperT includingFields( @Nonnull final EntitySelectable<Enti
      *
      * @param fields
      *            The fields to be excluded in the update execution.
-     *
      * @return The same fluent helper which will exclude the specified fields in an update request.
      */
     @Nonnull
@@ -255,4 +261,33 @@ public final FluentHelperT modifyingEntity()
         updateStrategy = UpdateStrategy.MODIFY_WITH_PATCH;
         return getThis();
     }
+
+    /**
+     * Allows to control that the request to update the entity is sent with the HTTP method PATCH and its payload
+     * contains the changed fields only, with different strategies for handling nested fields.
+     *
+     * @param strategy
+     *            The strategy to use for the PATCH update.
+     * @return The same fluent helper which will modify the entity in the remote system.
+     * @throws IllegalArgumentException
+     *             If an unknown ModifyPatchStrategy is provided.
+     */
+    @Nonnull
+    public final FluentHelperT modifyingEntity( @Nonnull final ModifyPatchStrategy strategy )
+    {
+        switch( strategy ) {
+            case SHALLOW:
+                return modifyingEntity();
+            case RECURSIVE_DELTA:
+                updateStrategy = UpdateStrategy.MODIFY_WITH_PATCH_RECURSIVE_DELTA;
+                break;
+            case RECURSIVE_FULL:
+                updateStrategy = UpdateStrategy.MODIFY_WITH_PATCH_RECURSIVE_FULL;
+                break;
+            default:
+                throw new IllegalArgumentException("Unknown ModifyPatchStrategy: " + strategy);
+        }
+        return getThis();
+    }
+
 }

datamodel/odata/odata-core/src/main/java/com/sap/cloud/sdk/datamodel/odata/helper/ModifyPatchStrategy.java

@@ -0,0 +1,18 @@
+package com.sap.cloud.sdk.datamodel.odata.helper;
+
+/**
+ * Strategy to determine how a patch operation should be applied to an entity.
+ */
+public enum ModifyPatchStrategy
+{
+    /** Only the top level fields can be patched */
+    SHALLOW,
+
+    /** All top level and nested fields can be patched, resulting in JSON containing only the changed fields */
+    RECURSIVE_DELTA,
+
+    /**
+     * All top level and nested fields can be patched, resulting in JSON containing the full value of complex object.
+     */
+    RECURSIVE_FULL
+}

datamodel/odata/odata-core/src/main/java/com/sap/cloud/sdk/datamodel/odata/helper/ODataEntitySerializer.java

@@ -9,6 +9,7 @@
 import java.util.Collection;
 import java.util.HashSet;
 import java.util.List;
+import java.util.Map;
 import java.util.Set;
 import java.util.function.BiConsumer;
 import java.util.function.BiPredicate;
@@ -104,7 +105,7 @@ static String serializeEntityForCreate( @Nonnull final VdmEntity<?> entity )
      * @return The serialized JSON string for entity update request.
      */
     @Nonnull
-    static String serializeEntityForUpdatePatch(
+    static String serializeEntityForUpdatePatchShallow(
         @Nonnull final VdmEntity<?> entity,
         @Nonnull final Collection<FieldReference> includedFields )
     {
@@ -122,6 +123,143 @@ static String serializeEntityForUpdatePatch(
         return GSON_SERIALIZING_NULLS.toJson(partialEntity);
     }
 
+    /**
+     * Serializes an entity for update request (PATCH) including changes in nested properties. Allowing null values.
+     * Resulting JSON contains the full value of complex fields for changing any nested field.
+     *
+     * @param entity
+     *            The OData V2 entity reference.
+     * @param includedFields
+     *            Collection of fields to be included in the update (PATCH) request.
+     * @return The serialized JSON string for entity update request.
+     */
+    @Nonnull
+    static String serializeEntityForUpdatePatchRecursiveFull(
+        @Nonnull final VdmEntity<?> entity,
+        @Nonnull final Collection<FieldReference> includedFields )
+    {
+        final JsonObject fullEntityJson = GSON_SERIALIZING_NULLS.toJsonTree(entity).getAsJsonObject();
+        final JsonObject patchObject = new JsonObject();
+
+        final Set<String> changedFieldNames = new HashSet<>(entity.getChangedFields().keySet());
+        includedFields.stream().map(FieldReference::getFieldName).forEach(changedFieldNames::add);
+        changedFieldNames.forEach(key -> patchObject.add(key, fullEntityJson.get(key)));
+
+        entity
+            .toMapOfFields()
+            .entrySet()
+            .stream()
+            .filter(entry -> !patchObject.has(entry.getKey()))
+            .filter(entry -> entry.getValue() instanceof VdmComplex<?>)
+            .filter(entry -> containsNestedChangedFields((VdmComplex<?>) entry.getValue()))
+            .forEach(entry -> patchObject.add(entry.getKey(), fullEntityJson.get(entry.getKey())));
+
+        log.debug("The following object is serialized for update : {}.", patchObject);
+
+        return GSON_SERIALIZING_NULLS.toJson(patchObject);
+    }
+
+    /**
+     * Checks if the given complex object contains any changed fields in its nested fields.
+     *
+     * @param vdmComplex
+     *            the complex object to check
+     * @return true if the complex object contains any changed fields, false otherwise
+     */
+    private static boolean containsNestedChangedFields( final VdmComplex<?> vdmComplex )
+    {
+        if( !vdmComplex.getChangedFields().isEmpty() ) {
+            return true;
+        }
+
+        return vdmComplex
+            .toMapOfFields()
+            .values()
+            .stream()
+            .filter(complexField -> complexField instanceof VdmComplex<?>)
+            .map(complexField -> (VdmComplex<?>) complexField)
+            .anyMatch(ODataEntitySerializer::containsNestedChangedFields);
+    }
+
+    /**
+     * Serializes an entity for update request (PATCH) including changes in nested properties. Allowing null values.
+     * Resulting JSON contains only the changed fields (including nested changes).
+     *
+     * @param entity
+     *            The OData V2 entity reference.
+     * @param includedFields
+     *            Collection of fields to be included in the update (PATCH) request.
+     * @return The serialized JSON string for entity update request.
+     */
+    @Nonnull
+    static String serializeEntityForUpdatePatchRecursiveDelta(
+        @Nonnull final VdmEntity<?> entity,
+        @Nonnull final Collection<FieldReference> includedFields )
+    {
+        final JsonObject fullEntityJson = GSON_SERIALIZING_NULLS.toJsonTree(entity).getAsJsonObject();
+        final JsonObject patchObject = new JsonObject();
+
+        // Recursively build patch object from changed fields
+        final JsonObject tempPatchObject = createPatchObjectRecursiveDelta(entity, fullEntityJson);
+
+        // Add included fields (from the root only)
+        includedFields
+            .stream()
+            .map(FieldReference::getFieldName)
+            .forEach(key -> patchObject.add(key, fullEntityJson.get(key)));
+
+        // Merge all fields from the tempPatchObject if not already present
+        tempPatchObject
+            .entrySet()
+            .stream()
+            .filter(entry -> !patchObject.has(entry.getKey()))
+            .forEach(entry -> patchObject.add(entry.getKey(), entry.getValue()));
+
+        log.debug("The following delta object is serialized for update : {}.", patchObject);
+
+        return GSON_SERIALIZING_NULLS.toJson(patchObject);
+    }
+
+    /**
+     * Recursively builds a patch object for a VdmObject by including only changed fields. Complex fields are traversed
+     * recursively.
+     *
+     * @param vdmObject
+     *            the VdmObject (entity or complex) to build the patch from
+     * @param jsonObject
+     *            the full JSON representation of this object
+     * @return a JsonObject that contains only changed fields (including nested changes)
+     */
+    @Nonnull
+    private static
+        JsonObject
+        createPatchObjectRecursiveDelta( @Nonnull final VdmObject<?> vdmObject, @Nonnull final JsonObject jsonObject )
+    {
+        final JsonObject patch = new JsonObject();
+
+        // Process all complex fields
+        vdmObject
+            .toMapOfFields()
+            .entrySet()
+            .stream()
+            .filter(entry -> entry.getValue() instanceof VdmComplex<?>)
+            .map(entry -> {
+                final String fieldName = entry.getKey();
+                final VdmComplex<?> complexField = (VdmComplex<?>) entry.getValue();
+                // Recursively build patch for the complex field
+                final JsonObject childJsonObject =
+                    createPatchObjectRecursiveDelta(complexField, jsonObject.getAsJsonObject(fieldName));
+                return Map.entry(fieldName, childJsonObject);
+            })
+            .filter(entry -> !entry.getValue().isEmpty())
+            .forEach(entry -> patch.add(entry.getKey(), entry.getValue()));
+
+        // Add changed primitive fields
+        vdmObject.getChangedFields().keySet().forEach(key -> patch.add(key, jsonObject.get(key)));
+
+        return patch;
+    }
+
     private static void removeVersionIdentifier( @Nonnull final JsonObject jsonObject )
     {
         log.debug("Removing redundant \"versionIdentifier\" recursively from JSON object: {}", jsonObject);