Non-linked association overwritten on PATCH update [DATAREST-571]

Ryan Evans opened DATAREST-571 and commented

When processing a PATCH update (save) for a repository, any non-linked associations for the entity being updated aren't merged correctly, causing the entire associated entity to be replaced (PUT behavior) instead of merged.

This issue did not exist in 2.2.1.

It looks as if the problem is around line 185 in org.springframework.data.rest.webmvc.json.DomainObjectReader#doMerge(...):

			if (child.isObject()) {

				if (associationLinks.isLinkableAssociation(property)) {
					continue;
				}

				BeanWrapper<T> wrapper = BeanWrapper.create(target, null);
				Object nested = wrapper.getProperty(property);

				if (nested != null) {
                                        // *** i.remove() is not called here ***
					doMerge((ObjectNode) child, nested, mapper);
				}

			}
		}

                // *** the associated object is overwritten by a NEW, empty object here ***
		return mapper.readerForUpdating(target).readValue(root);

Contrast this with the code from 2.2.1:

			} else if (child.isObject()) {

				PersistentProperty<?> property = findProperty(existingObject, entry.getKey(), mapper);

				if (property == null || associationLinks.isLinkableAssociation(property)) {
					continue;
				}

				BeanWrapper<T> wrapper = BeanWrapper.create(existingObject, null);
				Object nested = wrapper.getProperty(property);

				if (nested != null) {

					// Only remove the JsonNode if the object already exists. Otherwise it will be instantiated when the parent
					// gets deserialized.

                                        // *** i.remove is called, removing the child node from so it isn't processed again below ***
					i.remove();
					merge((ObjectNode) child, nested, mapper);
				}
			}

Affects: 2.2.2 (Evans SR2), 2.3 GA (Fowler)

1 votes, 3 watchers