(To be continued) Notes from task breakdown:

Validation:

• create StatementValidator interface in Wikibase\Repo\RestApi\Validation
  • has two methods: validate( array $serializedStatement ): ?ValidationError and getValidatedStatement(): ?Statement

• implement StatementValidator interface using SnakValidator and StatementDeserializer in new namespace similar to DataAccess (may have external dependencies)
  • deserializes the statement first and writes it to an instance property (with a getter method)
  • use SnakValidator for validation post deserialization

• create new EditMetadataValidator validator: data type validation for metadata fields (tags: array, bot: bool)

• use case validator has 3 dependencies: ItemIdValidator, StatementValidator, EditMetadataValidator

RouteHandler:

• builds Location header from GUID contained in the use case response object

Presenter:

• change the GetItemStatementJsonPresenter to StatementJsonPresenter for Statement presentation, change method signature to accept Statement as a param instead of response object

EditMetadata (new domain object)

• contains comment, tags, bot, base rev id, user

ItemRevision ("new" domain object)

• contains item, latest revision id, last modified

ItemUpdater:

• new service interface in Wikibase\Repo\RestApi\Domain\Services namespace
  • has method update( Item $item, EditMetadata $editMetadata ): ItemRevision
• implement using MediawikiEditEntity or its factory (EntityStore is too low level)

• new implementation in DataAccess namespace

use case life cycle:

• route handler creates request object with metadata and serialized statement
• use case deserializes statement
  • returns error response in case of failure
• use case validates item id, metadata and statement (using StatementValidator)
• item latest revision metadata lookup and redirect / not found handling
• load item using retriever
• generate guid using itemid and set on statement
• add statement to item using $item->addStatement
• save item, set revision id and last modified date
• respond with response object with statement returned from db and revision metadata

Tasks:
Silvan creates:

• spec
• business-logic only use case (start with happy path only?): AddItemStatement
  • create the "shell" of the AddItemStatementValidator and delegate to the deserializer for getValidatedStatement
  • create ItemUpdater interface, (re) create ItemRevision class, create EditMetadata class
• create StatementValidator
• create EditMetadataValidator
• add validation to use case (item id, edit metadata, statement)
  • create AddItemStatementValidator bundling the three validators

Jakob creates:

• implement ItemUpdater using MediawikiEditEntityFactory
• create initial AddItemStatementRouteHandler
  • unexpected error handling
  • auth header
• item does not exist handling
• generate location header from response
• spec tests

This is now ready for verification on beta!

Some example payloads for convenience:

{
	"statement": {
		"type": "statement",
		"mainsnak": {
			"snaktype": "novalue",
			"property": "P92"
		}
	}
}

{
	"statement": {
		"type": "statement",
		"mainsnak": {
			"snaktype": "value",
			"datavalue": {
				"value": "potato",
				"type": "string"
			},
			"property": "P92"
		}
	}
}

Verified. Some edge-case issues encountered and reported to the engineers. Tickets might surface at some point. Thanks

The last subtask that was solved in this sprint was T311287: 🟩️ Refuse to handle POST requests to /entities/items/{item_id}/statements when an item has been merged into another one which can be tested on https://wikidata.beta.wmflabs.org/wiki/Q12 (merged into Q593112).

Verified. Handling of redirected items indeed works, Location response header documented in the autodocs. All grand, thank you