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Merged
thjaeckle merged 4 commits into from
Jan 28, 2026
+290 −10
Merged

add deleteField mapping #2307

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8c81b56
add deleteField mapping
hu-ahmed Jan 17, 2026
d8289d9
add JsonFieldMarker for _deletedFields
hu-ahmed Jan 18, 2026
ff8b0d9
update the toString
hu-ahmed Jan 26, 2026
0e68887
review: don't use Optional as method parameters
thjaeckle Jan 28, 2026
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87 changes: 81 additions & 6 deletions ...src/main/java/org/eclipse/ditto/connectivity/service/mapping/NormalizedMessageMapper.java
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -50,7 +50,7 @@
* A message mapper implementation for normalized changes.
* Create-, modify-, merged- and deleted-events are mapped to nested sparse JSON.
* For complete thing deletions (ThingDeleted), a special `_deleted` field is included with the deletion timestamp.
* Partial deletions (AttributeDeleted, FeatureDeleted, etc.) are not mapped and will be dropped.
* Partial deletions (AttributeDeleted, FeatureDeleted, etc.) can be mapped to `_deletedFields` when enabled.
* All other signals and incoming messages are dropped.
*/
public final class NormalizedMessageMapper extends AbstractMessageMapper {
Expand All @@ -61,6 +61,7 @@ public final class NormalizedMessageMapper extends AbstractMessageMapper {
* Config property to project parts from the mapping result.
*/
public static final String FIELDS = "fields";
static final String INCLUDE_DELETED_FIELDS = "includeDeletedFields";

private static final JsonFieldDefinition<String> THING_ID = Thing.JsonFields.ID;
private static final JsonFieldDefinition<String> MODIFIED = Thing.JsonFields.MODIFIED;
Expand All @@ -74,9 +75,15 @@ public final class NormalizedMessageMapper extends AbstractMessageMapper {
FieldType.SPECIAL,
FieldType.HIDDEN,
JsonSchemaVersion.V_2);
private static final JsonFieldDefinition<JsonObject> DELETED_FIELDS =
JsonFactory.newJsonObjectFieldDefinition("_deletedFields",
FieldType.SPECIAL,
FieldType.HIDDEN,
JsonSchemaVersion.V_2);

@Nullable
private JsonFieldSelector jsonFieldSelector;
private boolean includeDeletedFields;

/**
* Constructs a new instance of NormalizedMessageMapper extension.
Expand All @@ -91,6 +98,7 @@ public final class NormalizedMessageMapper extends AbstractMessageMapper {
private NormalizedMessageMapper(final NormalizedMessageMapper copyFromMapper) {
super(copyFromMapper);
this.jsonFieldSelector = copyFromMapper.jsonFieldSelector;
this.includeDeletedFields = copyFromMapper.includeDeletedFields;
}

@Override
Expand All @@ -114,6 +122,9 @@ public void doConfigure(final Connection connection, final MappingConfig mapping
fields.ifPresent(s ->
jsonFieldSelector =
JsonFactory.newFieldSelector(s, JsonParseOptions.newBuilder().withoutUrlDecoding().build()));
includeDeletedFields = configuration.findProperty(INCLUDE_DELETED_FIELDS)
.map(Boolean::parseBoolean)
.orElse(false);
}

@Override
Expand All @@ -129,7 +140,7 @@ public DittoHeaders getAdditionalInboundHeaders(final ExternalMessage message) {
@Override
public List<ExternalMessage> map(final Adaptable adaptable) {
final TopicPath topicPath = adaptable.getTopicPath();
return isThingChangeEvent(topicPath, adaptable.getPayload())
return isThingChangeEvent(topicPath, adaptable.getPayload(), includeDeletedFields)
? Collections.singletonList(flattenAsThingChange(adaptable))
: Collections.emptyList();
}
Expand Down Expand Up @@ -157,15 +168,21 @@ private ExternalMessage flattenAsThingChange(final Adaptable adaptable) {

payload.getTimestamp().ifPresent(timestamp -> builder.set(MODIFIED, timestamp.toString()));
payload.getRevision().ifPresent(revision -> builder.set(REVISION, revision));

// Add _deleted field only for complete thing deletions (ThingDeleted events)
// Partial deletions (AttributeDeleted, FeatureDeleted, etc.) are not mapped
if (isThingDeleted(topicPath, payload)) {
payload.getTimestamp().ifPresent(timestamp ->
builder.set(DELETED, timestamp.toString())
);
}


if (includeDeletedFields) {
final JsonObject deletedFields = extractDeletedFields(topicPath, payload, path, payloadValue.orElse(null));
if (!deletedFields.isEmpty()) {
builder.set(DELETED_FIELDS, deletedFields);
}
}

builder.set(ABRIDGED_ORIGINAL_MESSAGE, abridgeMessage(adaptable));

final var json = builder.build();
Expand Down Expand Up @@ -212,13 +229,16 @@ private static JsonObject dittoHeadersToJson(final DittoHeaders dittoHeaders) {
.collect(JsonCollectors.fieldsToObject());
}

private static boolean isThingChangeEvent(final TopicPath topicPath, final Payload payload) {
private static boolean isThingChangeEvent(final TopicPath topicPath,
final Payload payload,
final boolean includeDeletedFields) {
final var isThingEvent =
topicPath.isGroup(TopicPath.Group.THINGS) && topicPath.isCriterion(TopicPath.Criterion.EVENTS);

final var isChange = topicPath.isAction(TopicPath.Action.CREATED)
|| topicPath.isAction(TopicPath.Action.MODIFIED)
|| topicPath.isAction(TopicPath.Action.MERGED)
|| (includeDeletedFields && topicPath.isAction(TopicPath.Action.DELETED))
|| isThingDeleted(topicPath, payload);

return isThingEvent && isChange;
Expand All @@ -229,6 +249,60 @@ private static boolean isThingDeleted(final TopicPath topicPath, final Payload p
JsonPointer.of(payload.getPath()).isEmpty();
}

private static JsonObject extractDeletedFields(final TopicPath topicPath,
final Payload payload,
final JsonPointer path,
@Nullable final JsonValue payloadValue)
{
if (payload.getTimestamp().isEmpty()) {
return JsonObject.empty();
}
final JsonObjectBuilder deletedFieldsBuilder = JsonFactory.newObjectBuilder();
final String timestamp = payload.getTimestamp().orElseThrow().toString();

if (topicPath.isAction(TopicPath.Action.DELETED) && !path.isEmpty()) {
deletedFieldsBuilder.set(path.toString(), timestamp);
return deletedFieldsBuilder.build();
}

if (topicPath.isAction(TopicPath.Action.MERGED) && payloadValue != null) {
if (payloadValue.isNull() && !path.isEmpty()) {
deletedFieldsBuilder.set(path.toString(), timestamp);
} else if (payloadValue.isObject()) {
extractNullsFromMergePatch(payloadValue.asObject(), path, deletedFieldsBuilder, timestamp);
}
}

return deletedFieldsBuilder.build();
}

private static void extractNullsFromMergePatch(final JsonObject mergeObject,
final JsonPointer basePath,
final JsonObjectBuilder deletedFieldsBuilder,
final String timestamp) {
mergeObject.forEach(jsonField -> {
final JsonKey key = jsonField.getKey();
if (isRegexDeletionKey(key)) {
return;
}
final JsonPointer currentPath = basePath.isEmpty()
? JsonPointer.empty().addLeaf(key)
: basePath.addLeaf(key);
final JsonValue value = jsonField.getValue();
if (value.isNull()) {
deletedFieldsBuilder.set(currentPath.toString(), timestamp);
} else if (value.isObject()) {
extractNullsFromMergePatch(value.asObject(), currentPath, deletedFieldsBuilder, timestamp);
}
});
}

private static boolean isRegexDeletionKey(final JsonKey key) {
final String keyString = key.toString();
return keyString.startsWith("{{") && keyString.endsWith("}}") &&
(keyString.contains("~") || keyString.contains("/"));
}

private static JsonObject filterNullValuesAndEmptyObjects(final JsonObject jsonObject) {
final JsonObjectBuilder builder = JsonFactory.newObjectBuilder();

Expand Down Expand Up @@ -258,6 +332,7 @@ public String toString() {
return getClass().getSimpleName() + " [" +
super.toString() +
", jsonFieldSelector=" + jsonFieldSelector +
", includeDeletedFields=" + includeDeletedFields +
"]";
}
}
184 changes: 182 additions & 2 deletions ...test/java/org/eclipse/ditto/connectivity/service/mapping/NormalizedMessageMapperTest.java
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -265,6 +265,68 @@ public void thingMergedWithOnlyNullValues() {
"}"));
}

@Test
public void thingMergedTracksDeletedFieldsFromNullValues() {
enableDeletedFields();
final JsonObject mergedObject = JsonObject.of("{\n" +
" \"attributes\": {\n" +
" \"location\": null,\n" +
" \"status\": \"active\"\n" +
" },\n" +
" \"features\": {\n" +
" \"sensor\": {\n" +
" \"properties\": {\n" +
" \"temp\": null,\n" +
" \"humidity\": 50\n" +
" }\n" +
" }\n" +
" }\n" +
"}");
final ThingMerged event = ThingMerged.of(ThingId.of("thing:merged"), JsonPointer.empty(), mergedObject,
1L, Instant.ofEpochSecond(1L), DittoHeaders.empty(), null);

final Adaptable adaptable = ADAPTER.toAdaptable(event);

Assertions.assertThat(mapToJson(adaptable))
.isEqualTo(JsonObject.of("{\n" +
" \"thingId\": \"thing:merged\",\n" +
" \"attributes\": {\n" +
" \"status\": \"active\"\n" +
" },\n" +
" \"features\": {\n" +
" \"sensor\": {\n" +
" \"properties\": {\n" +
" \"humidity\": 50\n" +
" }\n" +
" }\n" +
" },\n" +
" \"_modified\": \"1970-01-01T00:00:01Z\",\n" +
" \"_revision\": 1,\n" +
" \"_deletedFields\": {\n" +
" \"attributes\": {\n" +
" \"location\": \"1970-01-01T00:00:01Z\"\n" +
" },\n" +
" \"features\": {\n" +
" \"sensor\": {\n" +
" \"properties\": {\n" +
" \"temp\": \"1970-01-01T00:00:01Z\"\n" +
" }\n" +
" }\n" +
" }\n" +
" },\n" +
" \"_context\": {\n" +
" \"topic\": \"thing/merged/things/twin/events/merged\",\n" +
" \"path\": \"/\",\n" +
" \"value\":{\"attributes\":{\"status\":\"active\"},\"features\":{\"sensor\":{\"properties\":{\"humidity\":50}}}},\n" +
" \"headers\": {\n" +
" \"entity-revision\": \"1\",\n" +
" \"response-required\": \"false\",\n" +
" \"content-type\": \"application/merge-patch+json\"\n" +
" }\n" +
" }\n" +
"}"));
}

@Test
public void thingMergedWithExtraFields() {
final var thingId = ThingId.of("the.namespace:the-thing-id");
Expand Down Expand Up @@ -523,15 +585,125 @@ public void thingDeletedIsMappedWithDeletedTimestamp() {
}

@Test
public void deletedEventsAreNotMapped() {
assertNotMapped(AttributeDeleted.of(ThingId.of("thing:id"), JsonPointer.of("/the/quick/brown/fox/"), 3L,
public void deletedEventsAreNotMappedByDefault() {
assertNotMapped(AttributeDeleted.of(ThingId.of("thing:id"), JsonPointer.of("/the/quick/brown/fox"), 3L,
Instant.ofEpochSecond(3L), DittoHeaders.empty(), null));
assertNotMapped(FeaturePropertyDeleted.of(ThingId.of("thing:id"), "featureId",
JsonPointer.of("jumps/over/the/lazy/dog"), 4L, Instant.ofEpochSecond(4L), DittoHeaders.empty(), null));
assertNotMapped(FeatureDeleted.of(ThingId.of("thing:id"), "featureId", 5L, Instant.EPOCH,
DittoHeaders.empty(), null));
}

@Test
public void deletedEventsAreMappedWithDeletedFieldsWhenEnabled() {
enableDeletedFields();
final AttributeDeleted attributeDeleted = AttributeDeleted.of(
ThingId.of("thing:id"),
JsonPointer.of("/the/quick/brown/fox"),
3L,
Instant.ofEpochSecond(3L),
DittoHeaders.empty(),
null);

Assertions.assertThat(mapToJson(ADAPTER.toAdaptable(attributeDeleted)))
.isEqualTo(JsonObject.of("{\n" +
" \"thingId\": \"thing:id\",\n" +
" \"_modified\": \"1970-01-01T00:00:03Z\",\n" +
" \"_revision\": 3,\n" +
" \"_deletedFields\": {\n" +
" \"attributes\": {\n" +
" \"the\": {\n" +
" \"quick\": {\n" +
" \"brown\": {\n" +
" \"fox\": \"1970-01-01T00:00:03Z\"\n" +
" }\n" +
" }\n" +
" }\n" +
" }\n" +
" },\n" +
" \"_context\": {\n" +
" \"topic\": \"thing/id/things/twin/events/deleted\",\n" +
" \"path\": \"/attributes/the/quick/brown/fox\",\n" +
" \"value\": null,\n" +
" \"headers\": {\n" +
" \"entity-revision\": \"3\",\n" +
" \"response-required\": \"false\"\n" +
" }\n" +
" }\n" +
"}"));

final FeaturePropertyDeleted propertyDeleted = FeaturePropertyDeleted.of(
ThingId.of("thing:id"),
"featureId",
JsonPointer.of("jumps/over/the/lazy/dog"),
4L,
Instant.ofEpochSecond(4L),
DittoHeaders.empty(),
null);

Assertions.assertThat(mapToJson(ADAPTER.toAdaptable(propertyDeleted)))
.isEqualTo(JsonObject.of("{\n" +
" \"thingId\": \"thing:id\",\n" +
" \"_modified\": \"1970-01-01T00:00:04Z\",\n" +
" \"_revision\": 4,\n" +
" \"_deletedFields\": {\n" +
" \"features\": {\n" +
" \"featureId\": {\n" +
" \"properties\": {\n" +
" \"jumps\": {\n" +
" \"over\": {\n" +
" \"the\": {\n" +
" \"lazy\": {\n" +
" \"dog\": \"1970-01-01T00:00:04Z\"\n" +
" }\n" +
" }\n" +
" }\n" +
" }\n" +
" }\n" +
" }\n" +
" }\n" +
" },\n" +
" \"_context\": {\n" +
" \"topic\": \"thing/id/things/twin/events/deleted\",\n" +
" \"path\": \"/features/featureId/properties/jumps/over/the/lazy/dog\",\n" +
" \"value\": null,\n" +
" \"headers\": {\n" +
" \"entity-revision\": \"4\",\n" +
" \"response-required\": \"false\"\n" +
" }\n" +
" }\n" +
"}"));

final FeatureDeleted featureDeleted = FeatureDeleted.of(
ThingId.of("thing:id"),
"featureId",
5L,
Instant.EPOCH,
DittoHeaders.empty(),
null);

Assertions.assertThat(mapToJson(ADAPTER.toAdaptable(featureDeleted)))
.isEqualTo(JsonObject.of("{\n" +
" \"thingId\": \"thing:id\",\n" +
" \"_modified\": \"1970-01-01T00:00:00Z\",\n" +
" \"_revision\": 5,\n" +
" \"_deletedFields\": {\n" +
" \"features\": {\n" +
" \"featureId\": \"1970-01-01T00:00:00Z\"\n" +
" }\n" +
" },\n" +
" \"_context\": {\n" +
" \"topic\": \"thing/id/things/twin/events/deleted\",\n" +
" \"path\": \"/features/featureId\",\n" +
" \"value\": null,\n" +
" \"headers\": {\n" +
" \"entity-revision\": \"5\",\n" +
" \"response-required\": \"false\"\n" +
" }\n" +
" }\n" +
"}"));
}

@Test
public void nonThingEventsAreNotMapped() {
// command
Expand All @@ -553,6 +725,14 @@ private void assertNotMapped(final Signal signal) {
assertThat(underTest.map(ADAPTER.toAdaptable(signal))).isEmpty();
}

private void enableDeletedFields() {
final Map<String, JsonValue> options = Map.of(
NormalizedMessageMapper.INCLUDE_DELETED_FIELDS, JsonValue.of("true"));
underTest.configure(connection, connectivityConfig,
DefaultMessageMapperConfiguration.of("normalizer", options, Map.of(), Map.of()),
actorSystem);
}

private JsonObject mapToJson(final Adaptable message) {
return underTest.map(message)
.stream()
Expand Down
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