[Date Prev] | [Thread Prev] | [Thread Next] | [Date Next] -- [Date Index] | [Thread Index] | [List Home]
Subject: [OASIS Issue Tracker] (ODATA-1060) Improve specification of element response requirements
[ https://issues.oasis-open.org/browse/ODATA-1060?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=65778#comment-65778 ] Ralf Handl commented on ODATA-1060: ----------------------------------- This is a tough one: current use of OData is that $metadata describes a concrete, implemented service, not an abstract superset that may only be partially implemented. If a property is declared in $metadata, the client expects to get it in the response, even if it is null. To avoid breaking clients we recently added the preference omit-values=nulls that allows services to omit properties if they are null, but only if the client explicitly allows it with this preference. Now saying that a declared property that just happens to be annotated in a certain way need never be sent by a service will break clients that believe in our promise that “A service MUST NOT require the client to understand custom annotations in order to accurately interpret a response.” > Improve specification of element response requirements > ------------------------------------------------------ > > Key: ODATA-1060 > URL: https://issues.oasis-open.org/browse/ODATA-1060 > Project: OASIS Open Data Protocol (OData) TC > Issue Type: New Feature > Components: CSDL JSON , CSDL XML, Vocabularies > Environment: Schema > Reporter: George Ericson > Assignee: George Ericson > > Element response requirements: > There is ambiguity on the use and meaning of Nullable. > The reason is a distinction between the semantics of Nullable and whether or not implementation is required. > At least in one example, it is common practice to allow a Nullable=False property to be excluded from a response with the implied meaning of not implemented. The implementation requirement is not a term defined by OData. > Proposal: > 1) Add the following Term to Core: > <Term Name="ImplementationRequired" Type="Core.Tag" DefaultValue="false"> > <Annotation Term="Core.Description" String="If 'true', implementation of the qualified element is required. If the required element is Nullable and has no value, it may be omitted from a response. Otherwise it must be present in a related response." If an element is not required, it may be omitted from a related response. If an element is not required and is not Nullable and is not present in a response, it may be assumed to have not been implemented. If the element is Nullable and not present in a response, it may either have no value or have not been implemented." /> > </Term> > The following summarizes the above: > a. Nullable=True, Implementation=Optional => Omission implies no value or not implemented > b. Nullable=True, Implementation=Required => Omission implies no value > c. Nullable=False, Implementation=Optional => Omission implies not implemented, the value is unknown. > d. Nullable=False, Implementation=Required => Omission is not allowed, the property must indicate Null if no value. -- This message was sent by Atlassian JIRA (v6.2.2#6258)
[Date Prev] | [Thread Prev] | [Thread Next] | [Date Next] -- [Date Index] | [Thread Index] | [List Home]