The OData protocol is comprised of a set of specifications
for representing and interacting with structured content. The core
specification for the protocol is in [OData-Protocol];
this document is an extension of the core protocol. This document defines
representations for the OData requests and responses using the JavaScript
Object Notation (JSON), see [RFC7159].
An OData JSON payload may represent:
·
a single primitive value
·
a collection of primitive values
·
a single complex type value
·
a collection of complex type
values
·
a single entity or entity reference
·
a collection of entities or entity references
·
a collection of changes
·
a service document
describing the top-level resources exposed by the service
·
an error.
The key words “MUST”, “MUST NOT”, “REQUIRED”, “SHALL”, “SHALL
NOT”, “SHOULD”, “SHOULD NOT”, “RECOMMENDED”, “MAY”, and “OPTIONAL” in this
document are to be interpreted as described in [RFC2119].
[GeoJSON] Howard
Butler, Martin Daly, Alan Doyle, Sean Gillies, Stefan
Hagen and Tim Schaub, "The GeoJSON Format", RFC 7946, August 2016.
http://tools.ietf.org/html/rfc7946.
[I-JSON] Bray, T., Ed.,
"The I-JSON Message Format", RFC7493, March 2015. https://tools.ietf.org/html/rfc7493.
[OData-ABNF] OData
ABNF Construction Rules Version 4.0.
See link in “Related work” section on cover page.
[OData-CSDL] OData
Version 4.0 Part 3: Common Schema Definition Language (CSDL).
See link in “Related work” section on cover page.
[OData-CSDLXML] OData Common Schema
Definition Language (CSDL) XML Representation Version 4.01. See link in
"Related work" section on cover page.
[OData-Protocol] OData
Version 4.0 Part 1: Protocol.
See link in “Related work” section on cover page.
[OData-URL] OData
Version 4.0 Part 2: URL Conventions.
See link in "Related work" section on cover page.
[OData-VocCap] OData Vocabularies
Version 4.0: Capabilities Vocabulary.
See link in "Related work" section on cover page.
[OData-VocCore] OData Vocabularies
Version 4.0: Core Vocabulary.
See link in "Related work" section on cover page
[RFC2119] Bradner,
S., “Key words for use in RFCs to Indicate Requirement Levels”, BCP 14, RFC
2119, March 1997. https://tools.ietf.org/html/rfc2119.
[RFC3986] Berners-Lee,
T., Fielding, R., and L. Masinter, “Uniform Resource Identifier (URI): Generic
Syntax”, IETF RFC3986, January 2005. https://tools.ietf.org/html/rfc3986.
[RFC3987] Duerst,
M. and, M. Suignard, “Internationalized Resource Identifiers (IRIs)”, RFC 3987,
January 2005. https://tools.ietf.org/html/rfc3987.
[RFC4648] Josefsson, S,,
“The Base16, Base32, and Base64 Data Encodings", RFC 4648, October 2006. https://tools.ietf.org/html/rfc4648.
[RFC7159] Bray,
T., Ed., “The JavaScript Object Notation (JSON) Data Interchange Format”, RFC 7159,
March 2014. http://tools.ietf.org/html/rfc7159.
[RFC5646] Phillips,
A., Ed., and M. Davis, Ed., “Tags for Identifying Languages”, BCP 47, RFC 5646,
September 2009. http://tools.ietf.org/html/rfc5646.
[ECMAScript] ECMAScript
Language Specification Edition 5,1. June 2011. Standard ECMA-262. http://www.ecma-international.org/publications/standards/Ecma-262.htm.
Keywords defined by this specification use this monospaced font.
Normative source code uses this paragraph style.
Some sections of this specification are illustrated with
non-normative examples.
Example 1: text describing an example uses this paragraph
style
Non-normative
examples use this paragraph style.
All examples in this document are non-normative and
informative only.
All other text is normative unless otherwise labeled.
JSON, as described in [RFC7159], defines a text
format for serializing structured data. Objects are serialized as an unordered
collection of name/value pairs.
JSON does not define any semantics around the name/value
pairs that make up an object, nor does it define an extensibility mechanism for
adding control information to a payload.
OData’s JSON format extends JSON by defining general
conventions for name/value pairs that annotate a JSON object, property or
array. OData defines a set of canonical annotations for control information
such as ids, types, and links, and custom annotations MAY be used to add
domain-specific information to the payload.
A key feature of OData’s JSON format is to allow omitting
predictable parts of the wire format from the actual payload. To reconstitute
this data on the receiving end, expressions are used to compute missing links,
type information, and other control data. These expressions (together with the
data on the wire) can be used by the client to compute predictable payload
pieces as if they had been included on the wire directly.
Annotations are used in JSON to capture control information
that cannot be predicted (e.g., the next link of a collection) as well as a
mechanism to provide values where a computed value would be wrong (e.g., if the
media read link of one particular entity does not follow the standard URL
conventions). Computing values from metadata expressions is compute intensive
and some clients might opt for a larger payload size to avoid computational
complexity; to accommodate for this the Accept
header allows the client to control the amount of control information added to
the response.
To optimize streaming scenarios, there are a few
restrictions that MAY be imposed on the sequence in which name/value pairs
appear within JSON objects. For details on the ordering requirements see Payload Ordering Constraints.
3
Requesting the JSON Format
The OData JSON format can be requested using the $format query option in the request URL with the MIME
type application/json, optionally followed by
format parameters, or the case-insensitive abbreviation json
which MUST NOT be followed by format parameters.
Alternatively, this format can be requested using the Accept header with the MIME type application/json,
optionally followed by format parameters.
If specified, $format overrides
any value specified in the Accept header.
Possible format parameters are:
·
ExponentialDecimals
·
IEEE754Compatible
·
metadata (odata.metadata)
·
streaming (odata.streaming)
The names and values of these format parameters are
case-insensitive.
Services SHOULD advertise the supported MIME types by
annotating the entity container with the term Capabilities.SupportedFormats defined in [OData-VocCap],
listing all available formats and combinations of supported format parameters.
3.1 Controlling the Amount of Control
Information in Responses
The amount of control
information needed (or desired) in the payload depends on the client
application and device. The metadata parameter can
be applied to the Accept header of an OData request
to influence how much control information will be included in the response.
Other Accept header parameters
(e.g., streaming) are orthogonal to the metadata parameter and are therefore not mentioned in
this section.
If a client prefers a very small wire size and is
intelligent enough to compute data using metadata expressions, the Accept header should include metadata=minimal.
If computation is more critical than wire size or the client is incapable of
computing control information, metadata=full directs the service
to inline the control information that normally would be computed from metadata
expressions in the payload. metadata=none is an option for
clients that have out-of-band knowledge or don't require control information.
In addition the client may use the include-annotations
preference in the Prefer header to request
additional control information. Services supporting this MUST NOT omit control
information required by the chosen metadata
parameter, and services MUST NOT exclude the nextLink, deltaLink, and count if
they are required by the response type.
If the client includes the OData-MaxVersion
header in a request and does not specify the metadata
format parameter in either the Accept header or $format query option, the service MUST return at least
the minimal control information.
Note that in OData 4.0 the metadata
format parameter was prefixed with “odata.”.
Payloads with an OData-Version header equal to 4.0 MUST include the
“odata.” prefix. Payloads with an OData-Version header equal to 4.01 or greater SHOULD NOT include the “odata.” prefix.
3.1.1 metadata=minimal (odata.metadata=minimal)
The metadata=minimal format
parameter indicates that the service SHOULD remove computable control
information from the payload wherever possible. The response payload MUST
contain at least the following common annotations:
·
context: the root context URL of
the payload and the context URL for any deleted entries or added or deleted
links in a delta response, or for entities or entity collections whose set
cannot be determined from the root context URL
·
etag:
the ETag of the entity, as appropriate
·
count:
the total count of a collection of entities or collection of entity references,
if requested
·
nextLink:
the next link of a collection with partial results
·
deltaLink:
the delta link for obtaining changes to the result, if requested
In addition, odata annotations
MUST appear in the payload for cases where actual values are not the same as
the computed values and MAY appear otherwise. When odata
annotations appear in the payload, they are treated as exceptions to the
computed values.
Media entities and stream properties MAY in addition contain
the following annotations:
·
mediaEtag: the ETag of the stream, as appropriate
·
mediaContentType: the content type of the stream
3.1.2 metadata=full (odata.metadata=full)
The metadata=full format
parameter indicates that the service MUST include all control information
explicitly in the payload.
The full list of annotations
that may appear in an metadata=full response is as
follows:
·
context: the context URL for a
collection, entity, primitive value, or service document.
·
count:
the total count of a collection of entities or collection of entity references,
if requested.
·
nextLink:
the next link of a collection with partial results
·
deltaLink:
the delta link for obtaining changes to the result, if requested
·
id: the ID of the entity
·
etag:
the ETag of the entity
·
readLink: the link used to read the entity, if the
edit link cannot be used to read the entity
·
editLink: the link used to edit/update the entity, if
the entity is updatable and the id does not
represent a URL that can be used to edit the entity
·
navigationLink: the link used to
retrieve the values of a navigation property
·
associationLink: the link used to
describe the relationship between this entity and related entities
·
type:
the type of the containing object or targeted property if the type of the
object or targeted property cannot be heuristically determined
Media entities and stream properties may in addition contain
the following annotations:
·
mediaReadLink: the link used to read the stream
·
mediaEditLink: the link used to edit/update the
stream
·
mediaEtag: the ETag of the stream, as appropriate
·
mediaContentType: the content type of the stream
3.1.3 metadata=none (odata.metadata=none)
The metadata=none format
parameter indicates that the service SHOULD omit control information other than
nextLink
and count.
These annotations MUST continue to be included, as applicable, even in the metadata=none case.
It is not valid to specify metadata=none
on a delta request.
3.2 Controlling the Representation
of Numbers
The IEEE754Compatible=true
format parameter indicates that the service MUST serialize Edm.Int64 and Edm.Decimal
numbers (including the count, if requested) as strings.
This is in conformance with [I-JSON].
If not specified, or specified as IEEE754Compatible=false,
all numbers MUST be serialized as JSON numbers.
This enables support for JavaScript numbers that are defined
to be 64-bit binary format IEEE 754 values [ECMAScript]
(see section
4.3.1.9) resulting in integers losing precision past 15 digits, and
decimals losing precision due to the conversion from base 10 to base 2.
OData JSON payloads that format Edm.Int64
and Edm.Decimal values as strings MUST specify this
format parameter in the media type returned in the Content-Type
header.
For payloads with an OData-Version header
equal to 4.0
the ExponentialDecimals=true format parameter
indicates that the service MAY serialize Edm.Decimal
numbers (including the count, if requested) in
exponential notation (e.g. 1e-6 instead of 0.000001).
The sender of a request MUST specify ExponentialDecimals=true
in the Content-Type header if the request body
contains Edm.Decimal values in exponential
notation.
If not specified, or specified as ExponentialDecimals=false,
all Edm.Decimal values MUST be serialized in long
notation, using only an optional sign, digits, and an optional decimal point
followed by digits.
Payloads with an OData-Version header
equal to 4.01
or greater always allow exponential notation for numbers and the ExponentialNotation format parameter is not needed or
used.
This section describes common characteristics of the
representation for OData values in JSON. A request or response body consists of
several parts. It contains OData values as part of a larger document. Requests
and responses are structured almost identical; the few existing differences
will be explicitly called out in the respective subsections.
4.1 Header Content-Type
Requests and responses with a JSON message body MUST have a Content-Type header value of application/json.
Requests MAY add the charset
parameter to the content type. Allowed values are UTF-8, UTF-16, and UTF-32. If no
charset parameter is present, UTF-8 MUST be
assumed.
Responses MUST include the metadata parameter to specify the
amount of metadata included in the response.
Responses MUST include the IEEE754Compatible
parameter if Edm.Int64 and Edm.Decimal
numbers are represented as strings.
Requests and responses MAY add the streaming
parameter with a value of true or false, see section Payload Ordering Constraints.
Each message body is represented as a single JSON object.
This object is either the representation of an entity, an entity reference
or a complex type instance, or it
contains a name/value pair whose name MUST be value
and whose value is the correct representation for a primitive
value, a collection of primitive values,
a collection of complex values, a collection of entities, or a collection of objects
that represent changes to a previous result.
Client
libraries MUST retain the order of objects within an array in JSON responses.
4.3 Relative URLs
URLs present in a payload (whether request or response) MAY
be represented as relative URLs.
Relative URLs, other than those in type,
are relative to their base URL, which is
·
the context URL of the
same JSON object, if one exists, otherwise
·
the context URL of the enclosing object, if one exists, otherwise
·
the context URL of the next enclosing object, if one exists, etc.
until the document root, otherwise
·
the request URL.
For context URLs these rules apply starting with the second
bullet point.
Within the type annotation, relative URLs are
relative to the base type URL, which is
·
the type of the enclosing object, if
one exists, otherwise
·
the type of the next enclosing
object, if one exists, etc. until the document root, otherwise
·
the context URL of the document root, if one exists, otherwise
·
the request URL.
Processors expanding the URLs MUST use normal URL expansion
rules as defined in RFC3986. This means that if the
base URL is a context URL, the part starting with $metadata#
is ignored when resolving the relative URL.
Clients that receive relative URLs in response payloads
SHOULD use the same relative URLs, where appropriate, in request payloads (such
as bind operations and batch requests) and in
system query options (such as $id).
Example 2:
{
"@context":
"http://host/service/$metadata#Customers/$entity",
...
"@editLink":
"Customers('ALFKI')",
...
"Orders@navigationLink":
"Customers('ALFKI')/Orders",
...
}
The resulting absolute URLs are http://host/service/Customers('ALFKI')
and http://host/service/Customers('ALFKI')/Orders.
4.4 Payload
Ordering Constraints
Ordering constraints MAY be imposed on the JSON payload in
order to support streaming scenarios. These ordering constraints MUST only be
assumed if explicitly specified as some clients (and services) might not be
able to control, or might not care about, the order of the JSON properties in
the payload.
Clients can request that a JSON response conform to these
ordering constraints by specifying a media type of application/json with the streaming=true
parameter in the Accept header
or $format query option.
Services MUST return 406 Not Acceptable
if the client only requests streaming and the service does not support it.
Clients may specify the streaming=true
parameter in the Content-Type
header of requests to indicate that the request body follows the payload ordering
constraints. In the absence of this parameter, the service must assume that the
JSON properties in the request are unordered.
Processors MUST only assume streaming support if it is
explicitly indicated in the Content-Type header via
the streaming=true parameter.
Example 3: a payload with
Content-Type:
application/json;metadata=minimal;streaming=true
can be assumed to support streaming, whereas a payload with
Content-Type:
application/json;metadata=minimal
cannot be assumed to support streaming.
JSON producers are encouraged to follow the payload ordering
constraints whenever possible (and include the streaming=true
content type parameter) to support the maximum set of client scenarios.
To support streaming scenarios the following payload
ordering constraints have to be met:
·
If present, the context annotation MUST
be the first property in the JSON object.
·
The type annotation, if present, MUST
appear next in the JSON object.
·
The id and etag
annotations MUST appear before any property or property annotation.
·
All annotations for a structural or navigation property MUST
appear as a group immediately before the property they annotate. The one
exception is the nextLink annotation of an
collection which MAY appear after the collection it annotates.
·
All other odata annotations can
appear anywhere in the payload as long as they do not violate any of the above
rules.
·
For 4.0 payloads, annotations for navigation properties MUST appear
after all structural properties. 4.01 clients MUST NOT assume this ordering.
Note that, in OData 4.0, the streaming format parameter was prefixed with “odata.”. Payloads with an OData-Version header
equal to 4.0
MUST include the “odata.” prefix. Payloads with an OData-Version header equal to 4.01 or greater SHOULD NOT include the “odata.” prefix.
4.5 Control Information
In addition to the “pure data” a message body MAY contain
control information that is represented as annotations
whose names start with odata followed by a dot.
In requests and responses that do not contain the OData-Version header with a value of 4.0, the “odata.”
prefix SHOULD be omitted.
In some cases control information is required in request
payloads; this is called out in the following subsections.
Receivers that
encounter unknown annotations in any
namespace, including the odata namespace, MUST NOT stop processing and
MUST NOT signal an error.
4.5.1
Annotation context (odata.context)
The context
annotation returns the context URL (see [OData-Protocol])
for the payload. This URL can be absolute or relative.
The context
annotation is not returned if metadata=none is requested. Otherwise it
MUST be the first property of any JSON response.
The context
annotation MUST also be included in requests and responses for entities whose
entity set cannot be determined from the context URL of
the collection.
If the
metadata document referenced by the context
annotation is versioned, then the response MUST also include the Core.SchemaVersion annotation, defined in [OData-VocCore], to indicate the version of the
schema used to generate the response. For streamed JSON responses, this
annotation MUST immediately follow the context
annotation. If the Core.SchemaVersion annotation is
present, the SchemaVersion header, defined in [OData-Protocol], SHOULD be
used when retrieving the referenced metadata document.
For more information on the format of the context URL, see [OData-Protocol].
Request payloads MAY include a context URL as a base URL for
relative URLs in the request payload.
Example 4:
{
"@context": "http://host/service/$metadata#Customers/$entity",
"@metadataEtag": "W/\"A1FF3E230954908F\"",
"@Core.SchemaVersion": "2.0.1",
...
}
4.5.2 Annotation metadataEtag (odata.metadataEtag)
The metadataEtag annotation MAY
appear in a response in order to specify the entity tag (ETag) that can be used
to determine the version of the metadata of the response. If an ETag is
returned when requesting the metadata document, then the service SHOULD set the
metadataEtag annotation to the metadata document's
ETag in all responses when using metadata=minimal or metadata=full.
If no ETag is returned when requesting the metadata document, then the service
SHOULD NOT set the metadataEtag annotation in any
responses.
For details on how ETags are used, see [OData-Protocol].
4.5.3 Annotation type
(odata.type)
The type annotation specifies
the type of a JSON object or name/value pair. Its value is a URI that
identifies the type of the property or object. For built-in primitive types the
value is the unqualified name of the primitive type. For payloads described by
an OData-Version header with a
value of 4.0, this name MUST be prefixed with the
hash symbol (#); for non-OData
4.0 payloads, built-in primitive type values SHOULD be represented without the
hash symbol, but consumers of 4.01 or greater payloads MUST support values with
or without the hash symbol.. For all other types, the URI may be absolute or
relative to the type of the containing object. The
root type may be absolute or relative to the root context URL.
If the URI
references a metadata document (that is, it’s not just a fragment), and refers
to a specific version of that metadata, then the object or name/value pair MUST
also be annotated with the Core.SchemaVersion
annotation, defined in [OData-VocCore], to
indicate the version of the metadata document containing the corresponding
version of the type. For streamed
JSON responses, this annotation MUST immediately follow the type annotation. If the Core.SchemaVersion annotation is present, the Core.SchemaVersion header,
defined in [OData-Protocol], SHOULD
be used when retrieving the referenced metadata document.
For non-built in primitive types, the URI contains the
namespace-qualified or alias-qualified type, specified as a URI fragment. For
properties that represent a collection of values, the fragment is the
namespace-qualified or alias-qualified element type enclosed in parentheses and
prefixed with Collection. The namespace or alias
MUST be defined or the namespace referenced in the metadata document of the
service, see [OData-CSDLXML].
The type annotation MUST appear
in requests and in responses with minimal
or full metadata, if the type cannot be
heuristically determined, as described below, and one of the following is true:
·
The type is derived from the type specified for the (collection
of) entities or (collection of) complex type instances, or
·
The type is for a property whose type is not declared in $metadata.
The following heuristics are used to determine the primitive
type of a dynamic property in the absence of the type
annotation:
·
Boolean values have a first-class representation in JSON and do
not need any additional annotations.
·
Numeric values have a first-class representation in JSON but are
not further distinguished, so they include a type annotation
unless their type is Double.
·
The special floating-point values NaN,
INF, and -INF are
serialized as strings. In 4.0 responses these strings are serialized as the
value of the structural property and MUST have a type
annotation to specify the numeric type of the property.
·
String values do have a first class representation in JSON, but
there is an obvious collision: OData also encodes a number of other primitive
types as strings, e.g. DateTimeOffset, Int64 in the presence of the IEEE754Compatible
format parameter etc. If a property appears in JSON string format, it should be
treated as a string value unless the property is known (from the metadata document)
to have a different type.
For more information on namespace- and alias-qualified
names, see [OData-CSDLXML]..
Example 5: entity of type Model.VipCustomer
defined in the metadata document of the same service with a dynamic property of
type Edm.Date
{
"@context":
"http://host/service/$metadata#Customers/$entity",
"@type":
"#Model.VipCustomer",
"ID":
2,
"DynamicValue@type": "Date",
"DynamicValue": "2016-09-22",
...
}
Example 6: entity of type Model.VipCustomer
defined in the metadata document
of a different service
{
"@context":
"http://host/service/$metadata#Customers/$entity",
"@type":
"http://host/alternate/$metadata#Model.VipCustomer",
"ID":
2,
...
}
4.5.4 Annotation count
(odata.count)
The count annotation occurs only
in responses and can annotate any collection, see [OData-Protocol]
section 11.2.5.5 System Query Option $count.
Its value is an Edm.Int64 value
corresponding to the total count of members in the collection represented by
the request.
4.5.5 Annotation nextLink (odata.nextLink)
The nextLink annotation
indicates that a response is only a subset of the requested collection. It
contains a URL that allows retrieving the next subset of the requested
collection.
This annotation can also be applied to expanded to-many navigation properties.
4.5.6 Annotation
delta (odata.delta)
The delta annotation is applied
to a collection-valued navigation property within an added/changed entity in a
delta payload to represent changes in membership or value of nested entities.
The deltaLink annotation
contains a URL that can be used to retrieve changes to the current set of
results. The deltaLink annotation MUST only appear
on the last page of results. A page of results MUST NOT have both a deltaLink annotation and a nextLink
annotation.
4.5.8 Annotation id (odata.id)
The id annotation contains the
entity-id, see [OData-Protocol]. By convention the
entity-id is identical to the canonical URL of the entity, as defined in [OData-URL].
The id annotation MUST appear in
responses if metadata=full
is requested, or if metadata=minimal is requested and any of the entity's
key fields are omitted from the response or the entity-id is not
identical to the canonical URL of the entity after
·
IRI-to-URI conversion as defined in [RFC3987],
·
relative resolution as defined in section 5.2 of [RFC3986], and
·
percent-encoding normalization as defined in section 6 of [RFC3986].
Note that the entity-id MUST be invariant across languages,
so if key values are language dependent then the id
MUST be included if it does not match convention for the localized key values.
If the id is represented, it MAY be a relative URL.
If the entity is transient (i.e. cannot be read or updated),
the id annotation MUST appear and have the null value.
The id annotation MUST NOT
appear for a collection. Its meaning in this context is reserved for future
versions of this specification.
Entities with id equal to null cannot be compared to other entities, reread, or
updated. If metadata=minimal
is specified and the id is not present in the
entity then the canonical URL MUST be used as the entity-id.
4.5.9 Annotation editLink and readLink (odata.editLink and odata.readLink)
The editLink
annotation contains the edit URL of the entity; see [OData-Protocol].
The readLink annotation contains
the read URL of the entity or collection; see [OData-Protocol].
The editLink and readLink annotations are ignored in request payloads and
not written in responses if metadata=none is requested.
The default value of both the edit URL and read URL is the
entity's entity-id appended with a
cast segment to the type of the entity if its type is derived from the declared
type of the entity set. If neither the editLink nor
the readLink annotation is present in an entity,
the client uses this default value for the edit URL.
For updatable entities:
·
The editLink annotation is written if
metadata=full
is requested or if metadata=minimal is requested and the edit URL
differs from the default value of the edit URL.
·
The readLink annotation is written if
the read URL is different from the edit URL. If no readLink
annotation is present, the read URL is identical to the edit URL.
For read-only entities:
·
The readLink annotation is written if
metadata=full
is requested or if metadata=minimal is requested and its value differs
from the default value of the read URL.
·
The readLink annotation may also be
written if metadata=minimal
is specified in order to signal that an individual entity is read-only.
For collections:
·
The readLink annotation, if written,
MUST be the request URL that produced the collection.
·
The editLink annotation MUST NOT be
written as its meaning in this context is reserved for future versions of this
specification.
4.5.10 Annotation
etag (odata.etag)
The etag annotation MAY be
applied to an entity in
a response. The value of the annotation is an entity tag (ETag) which is an
opaque string value that can be used in a subsequent request to determine if
the value of the entity has changed.
For details on how ETags are used, see [OData-Protocol].
The etag
annotation is ignored in request payloads and not written in responses if metadata=none
is requested.
4.5.11 Annotation navigationLink and associationLink (odata.navigationLink and odata.associationLink)
The navigationLink annotation in a response contains a navigation
URL that can be used to retrieve an entity or collection of entities
related to the current entity via a navigation
property.
The default computed value of a navigation URL is the
value of the read URL appended
with a segment containing the name of the navigation property. The service MAY
omit the navigationLink annotation if metadata=minimal
has been specified on the request and the navigation link matches this computed
value.
The
associationLink
annotation in a response contains an association URL that can be used to
retrieve a reference to an entity or a collection of references to entities
related to the current entity via a navigation property.
The default computed value of an association URL is
the value of the navigation URL appended with /$ref.
The service MAY omit the associationLink annotation
if the association link matches this computed value.
The navigationLink
and associationLink annotations are ignored in
request payloads and not written in responses if metadata=none is requested.
4.5.12 Annotation media* (odata.media*)
For media entities and stream properties at least one of the annotations mediaEditLink and mediaReadLink
MUST be included in responses if they don't follow standard URL conventions as
defined in OData-URL or if metadata=full
is requested.
The mediaEditLink annotation
contains a URL that can be used to update the binary stream associated with the
media entity or stream property. It MUST be included for updatable media
entities if it differs from the value of the id,
and for updatable stream properties if it differs from standard URL
conventions.
The mediaReadLink annotation
contains a URL that can be used to read the binary stream associated with the
media entity or stream property. It MUST be included if its value differs from
the value of the associated mediaEditLink, if
present, or the value of the id
for media entities if the associated mediaEditLink
is not present.
The mediaContentType annotation
MAY be included; its value SHOULD match the content type of the binary stream
represented by the mediaReadLink URL. This is only a
hint; the actual content type will be included in a header when the resource is
requested.
The mediaEtag annotation MAY be
included; its value is the ETag of the binary stream represented by this media
entity or stream property.
The media* annotations are
ignored in request payloads and not written in responses if metadata=none
is requested.
Example 7:
{
"@context":
"http://host/service/$metadata#Employees/$entity",
"@mediaReadLink":
"Employees(1)/$value",
"@mediaContentType":
"image/jpeg",
"ID":
1,
...
}
A service document in JSON is represented as a single JSON
object with at least the context annotation and a property value.
The value of the context annotation MUST be the URL
of the metadata document, without any fragment part.
The value of the value property
MUST be a JSON array containing one element for each entity set and function
import with an explicit or default value of true
for the attribute IncludeInServiceDocument and each
singleton exposed by the service, see [OData-CSDLXML]..
Each element MUST be a JSON object with at least two
name/value pairs, one with name name containing the
name of the entity set, function import, or singleton, and one with name url containing the URL of the entity set, which may be an
absolute or a relative URL. It MAY contain a
name/value pair with name title containing a
human-readable, language-dependent title for the object.
JSON objects representing an entity set MAY contain an
additional name/value pair with name kind and a
value of EntitySet. If the kind
name/value pair is not present, the object MUST represent an entity set.
JSON objects representing a function import MUST contain the
kind name/value pair with a value of FunctionImport.
JSON objects representing a singleton MUST contain the kind name/value pair with a value of Singleton.
JSON objects representing a related service document MUST
contain the kind name/value pair with a value of ServiceDocument.
Clients that
encounter unknown values of the kind name/value
pair not defined in this version of the specification MUST NOT stop processing and MUST NOT signal an error.
Service documents MAY contain annotations in any of its JSON objects.
Services MUST NOT produce name/value pairs other than the ones explicitly
defined in this section, and clients MUST ignore unknown name/value pairs.
Example 8:
{
"@context": "http://host/service/$metadata",
"value": [
{
"name": "Orders",
"kind": "EntitySet",
"url": "Orders"
},
{
"name": "OrderItems",
"title": "Order Details",
"url": "OrderItems"
},
{
"name": "TopProducts",
"title": "Best-Selling Products",
"kind": "FunctionImport",
"url": "TopProducts"
},
{
"name": "MainSupplier",
"title": "Main Supplier",
"kind": "Singleton",
"url": "MainSupplier"
},
{
"name": "Human Resources",
"kind": "ServiceDocument",
"url": "http://host/HR/"
}
]
}
An entity is serialized as a JSON object.
Each property to be
transmitted is represented as a name/value pair within the object. The order
properties appear within the object is considered insignificant.
An entity in a payload may be a complete entity, a projected
entity (see System Query Option $select [OData-Protocol]), or a partial entity update (see Update
an Entity in [OData-Protocol]).
An entity representation can be (modified and) round-tripped
to the service directly. The context
URL is used in requests only as a base for relative
URLs.
Example 9: entity with metadata=minimal
{
"@context":
"http://host/service/$metadata#Customers/$entity",
"ID":
"ALFKI",
"CompanyName":
"Alfreds Futterkiste",
"ContactName":
"Maria Anders",
"ContactTitle":
"Sales Representative",
"Phone":
"030-0074321",
"Fax":
"030-0076545",
"Address":
{
"Street":
"Obere Str. 57",
"City":
"Berlin",
"Region":
null,
"PostalCode":
"D-12209"
}
}
Example 10: entity with metadata=full
{
"@context":
"http://host/service/$metadata#Customers/$entity",
"@id": "Customers('ALFKI')",
"@etag": "W/\"MjAxMy0wNS0yN1QxMTo1OFo=\"",
"@editLink": "Customers('ALFKI')",
"ID":
"ALFKI",
"CompanyName":
"Alfreds Futterkiste",
"ContactName":
"Maria Anders",
"ContactTitle":
"Sales Representative",
"Phone":
"030-0074321",
"Fax":
"030-0076545",
"Address":
{
"Street":
"Obere Str. 57",
"City":
"Berlin",
"Region": null,
"PostalCode": "D-12209",
"Country@associationLink":"Customers('ALFKI')/Address/Country/$ref",
"Country@navigationLink": "Customers('ALFKI')/Address/Country"
},
"Orders@associationLink": "Customers('ALFKI')/Orders/$ref",
"Orders@navigationLink": "Customers('ALFKI')/Orders"
}
A property within an entity or complex type instance is
represented as a name/value pair. The name MUST be the name of the property;
the value is represented depending on its type as a primitive
value, a complex value, a collection of primitive values, or a collection of
complex values.
7.1 Primitive Value
Primitive values are represented following the rules of [RFC7159].
Null values are represented as the JSON literal null.
Values of type Edm.Boolean are
represented as the JSON literals true and false
Values of types Edm.Byte, Edm.SByte, Edm.Int16, Edm.Int32, Edm.Int64, Edm.Single, Edm.Double, and Edm.Decimal are represented as JSON numbers, except for NaN, INF, and –INF which are represented as strings in OData 4.0. In
OData 4.01, they are represented as properties annotated with the Core.NumericValueException
annotation term as defined in [OData-VocCore].
Values of type Edm.String are
represented as JSON strings, using the JSON string escaping rules.
Values of type Edm.Binary, Edm.Date, Edm.DateTimeOffset, Edm.Duration, Edm.Guid, and Edm.TimeOfDay are represented as JSON strings whose
content satisfies the rules binaryValue, dateValue, dateTimeOffsetValue,
durationValue, guidValue,
and timeOfDayValue respectively, in [OData-ABNF].
Enumeration values are represented as JSON strings whose
content satisfies the rule enumValue in [OData-ABNF]. The preferred representation is the enumerationMember. If no enumerationMember
(or combination of named
enumeration members) is available, the enumMemberValue
representation may be used.
Geography and geometry values are represented as geometry
types as defined in [GeoJSON], with the following
modifications:
·
Keys SHOULD be ordered with type first, then coordinates, then
any other keys
·
The coordinates member of a LineString can have zero or more positions
·
If the optional CRS object is present, it MUST be of type name, where the value of the name
member of the contained properties object is an
EPSG SRID legacy identifier.
Geography and geometry types have the same
representation in a JSON payload. Whether the value represents a geography type
or geometry type is inferred from its usage or specified using the type
annotation.
Example 11:
{
"NullValue": null,
"TrueValue": true,
"FalseValue": false,
"BinaryValue": "T0RhdGE",
"IntegerValue": -128,
"DoubleValue": 3.1415926535897931,
"SingleValue@Core.NumericValueException": "INF",
"DecimalValue": 34.95,
"StringValue": "Say
\"Hello\",\nthen go",
"DateValue": "2012-12-03",
"DateTimeOffsetValue": "2012-12-03T07:16:23Z",
"DurationValue": "P12DT23H59M59.999999999999S",
"TimeOfDayValue": "07:59:59.999",
"GuidValue": "01234567-89ab-cdef-0123-456789abcdef",
"Int64Value": 0,
"ColorEnumValue": "Yellow",
"GeographyPoint": {"type":
"Point","coordinates":[142.1,64.1]}
}
7.2 Complex
Value
A complex value is represented as a single JSON object
containing one name/value pair for each property that makes up the complex
type. Each property value is formatted as appropriate for the type of the
property.
It MAY have name/value pairs for instance annotations,
including odata annotations.
Example 12:
{
"@context":
"http://host/service/$metadata#Customers/$entity",
...
"Address": {
"Street": "Obere Str. 57",
"City": "Berlin",
"Region": null,
"PostalCode": "D-12209"
}
}
A
complex value with no selected properties, or no defined properties (such as an
empty open complex type or complex type with no structural properties) is
represented as an empty JSON object.
A collection of primitive values is represented as a JSON
array; each element in the array is the representation of a primitive value. A JSON literal null represents a null value within the collection. An
empty collection is represented as an empty array.
Example 13: partial collection of strings with next link
{
"@context":
"http://host/service/$metadata#Customers/$entity",
...
"EmailAddresses": [
"Julie@Swansworth.com",
"Julie.Swansworth@work.com"
],
"EmailAddresses@nextLink": "..."
}
7.4 Collection of Complex Values
A collection of complex values is represented as a JSON
array; each element in the array is the representation of a complex value. A JSON literal null represents a null value within the collection. An
empty collection is represented as an empty array.
Example 14: partial collection of complex values with next
link
{
"PhoneNumbers": [
{
"Number": "425-555-1212",
"Type": "Home"
},
{
"@type": "#Model.CellPhoneNumber",
"Number": "425-555-0178",
"Type": "Cell",
"Carrier": "Sprint"
}
],
"PhoneNumbers@nextLink": "..."
}
7.5 Untyped Value
OData 4.01 adds the built-in abstract types Edm.Untyped and Collection(Edm.Untyped)that
services can use to advertise in metadata that there is a property of a
particular name present, but there is no type to describe the structure of the
property’s values.
The value of an Edm.Untyped
property MAY be a primitive value, a structural value, or a collection. If a
collection, it may contain any combination of primitive values, structural
values, and collections.
The value of a property of type Collection(Edm.Untyped)MUST
be a collection, and it MAY contain any combination of primitive values,
structural values, and collections.
Untyped values are the only place where a collection can
directly contain a collection, or a collection can contain a mix of primitive
values, structural values, and collections.
All children of an untyped property are assumed to be
untyped unless they are annotated with the type annotation, in which case
they MUST conform to the type described by the annotation.
A navigation property is a reference from a source entity to
zero or more related entities.
8.1 Navigation Link
The navigation link for a navigation property is represented
as a navigationLink annotation on the navigation property.
Its value is an absolute or relative URL that
allows retrieving the related entity or collection of entities.
The navigation link for a navigation property is only
represented if the client requests metadata=full or
the navigation link cannot be computed, e.g. if it is within a collection of
complex type instances. If it is represented it MUST immediately precede the
expanded navigation property if the latter is represented.
Example 15:
{
"@context": "http://host/service/$metadata#Customers/$entity",
...
"Orders@navigationLink":
"Customers('ALFKI')/Orders",
...
}
The association link for a navigation property is
represented as an associationLink annotation on the
navigation property. Its value is an absolute or relative
URL that can be used to retrieve the reference or collection of references
to the related entity or entities.
The association link for a navigation property is only
represented if the client requests metadata=full or
the association link cannot be computed by appending /$ref
to the navigation link. If it is represented, it MUST immediately precede the
navigation link if the latter is represented, otherwise it MUST immediately
precede the expanded navigation property if it is represented.
Example 16:
{
"@context": "http://host/service/$metadata#Customers/$entity",
...
"Orders@associationLink":
"Customers('ALFKI')/Orders/$ref",
...
}
8.3 Expanded Navigation Property
An expanded navigation property is represented as a
name/value pair where the name is the name of the navigation property, and the
value is the representation of the related entity or collection of entities.
If at most one entity can be related, the value is the
representation of the related entity, or null if no
entity is currently related.
If a collection of entities can be related, it is
represented as a JSON array. Each element is the representation
of an entity or the representation of an
entity reference. An empty collection of entities (one that contains no
entities) is represented as an empty JSON array. The navigation property MAY be
annotated with context, count or nextLink.
If a navigation property is expanded with the suffix /$count,
only the count annotation is represented.
Example 17:
{
"@context": "http://host/service/$metadata#Customers/$entity",
...
"Orders@count": 42,
"Orders": [ ... ],
"Orders@nextLink": "...",
...
}
When inserting a new entity with a POST
request, related new entities MAY be specified using the same representation as
for an expanded navigation property.
Deep inserts are not allowed in update operations using PUT or PATCH requests.
Example 18: inserting a new order for a new customer with
order items related to existing products:
{
"ID": 11643,
"Amount": 100,
...,
"Customer":
{
"ID":
"ANEWONE",
...
},
"Items":
[
{
"Product": { "@id": "Products(28)" },
"Quantity": 1,
...
},
{
"Product": { "@id": "Products(39)" },
"Quantity": 5,
...
}
]
}
8.5 Bind Operation
When inserting or updating an entity, relationships of
navigation properties MAY be inserted or updated via bind operations.
For requests containing an OData-Version
header with a value of 4.0, a bind operation is
encoded as a property annotation odata.bind on the navigation
property it belongs to and has a single value for single-valued navigation
properties or an array of values for collection navigation properties. For
nullable single-valued navigation properties the value null
may be used to remove the relationship.
Example 19: assign an existing product to an existing
category with a partial update request against the product
PATCH
http://host/service/Products(42) HTTP/1.1
{
"Category@odata.bind":
"Categories(6)"
}
The values are the ids
of the related entities. They MAY be absolute or relative
URLs.
For requests containing an OData-Version
header with a value of 4.01, a relationship is
bound to an existing entity using the same representation as for an expanded entity reference.
Example 20: assign an existing product to an existing
category with a partial update request against the product
PATCH
http://host/service/Products(42) HTTP/1.1
{
"Category":
{"@id": "Categories(6)"}
}
Example 21: submit a partial update request to:
·
modify the name of an existing category
·
assign an existing product with the id 42 to the category
·
assign an existing product 57 to the category and update its name
·
create a new product named “Wedges” and assign it to the category
at the end of the request, the updated category
contains exactly the three specified products.
PATCH
http://host/service/Categories(6) HTTP/1.1
{
"Name":
"UpdatedCategory",
"Products":
[
{
"@id": "Products(42)"
},
{
"@id": "Products(57)",
"Name": "Widgets"
},
{
"Name": "Wedges"
}
]
}
OData 4.01 services MUST support both the OData 4.0
representation, for requests containing an OData-Version
header with a value of 4.0, and the OData 4.01
representation, for requests containing an OData-Version
header with a value of 4.01. Clients MUST NOT use @odata.bind in requests with an OData-Version
header with a value of 4.01.
For insert operations collection navigation property bind
operations and deep insert operations can be combined. For OData 4.0 requests,
the bind operations MUST appear before the deep insert operations in the
payload.
For update operations a bind operation on a collection navigation
property adds additional relationships, it does not replace existing
relationships, while bind operations on an entity navigation property update
the relationship.
An entity or
complex type instance can have one or more stream properties.
The actual stream
data is not usually contained in the representation. Instead stream property
data is generally read and edited via URLs.
Depending on the metadata level, the stream property MAY be annotated to
provide the read link, edit link, content type, and ETag of the media stream
through a set of media* annotations. If the actual stream data is included inline, it is
represented as a base64url-encoded string value, see [RFC4648], section 5.
Example 20:
{
"@context": "http://host/service/$metadata#Products/$entity",
...
"Thumbnail@mediaReadLink": "http://server/Thumbnail546.jpg",
"Thumbnail@mediaEditLink": "http://server/uploads/Thumbnail546.jpg",
"Thumbnail@mediaContentType": "image/jpeg",
"Thumbnail@mediaEtag": "W/\"####\"",
"Thumbnail": "...base64url encoded value...",
...
}
Media entities are entities that describe a media resource,
for example a photo. They are represented as entities that contain additional media* annotations.
If the actual
stream data for the media entity is included, it is represented as property
named $value whose string value is the base64url-encoded value of the
media stream, see [RFC4648], section 5.
Example 21:
{
"@context":
"http://host/service/$metadata#Employees/$entity",
"@mediaReadLink":
"Employees(1)/$value",
"@mediaContentType":
"image/jpeg",
"$value":
"...base64url encoded value...",
"ID":
1,
...
}
11 Individual Property or Operation
Response
An individual property or operation response is represented
as a JSON object.
A single-valued property or operation response that has the null value does not have a representation; see [OData-Protocol].
A property or operation response that is of a primitive type
is represented as an object with a single name/value pair, whose name is value and whose value is a primitive
value.
A property or operation response that is of complex type is
represented as a complex value.
A property or operation response that is of a collection
type is represented as an object with a single name/value pair whose name is value. Its value is the JSON representation of a collection of complex type values or collection of primitive values.
Example 22: primitive value
{
"@context": "http://host/service/$metadata#Edm.String",
"value": "Pilar Ackerman"
}
Example 23: collection of primitive values
{
"@context":
"http://host/service/$metadata#Collection(Edm.String)",
"value": ["small", "medium", "extra
large"]
}
Example 24: empty collection of primitive values
{
"@context": "http://host/service/$metadata#Collection(Edm.String)",
"value": []
}
Example 25: complex value
{
"@context": "http://host/service/$metadata#Model.Address",
"Street": "12345 Grant Street",
"City": "Taft",
"Region": "Ohio",
"PostalCode": "OH 98052",
"Country@navigationLink": "Countries('US')"
}
Example 26: empty collection of complex values
{
"@context":"http://host/service/$metadata#Collection(Model.Address)",
"value": []
}
Note: the context URL is optional in requests.
12 Collection of Entities
A collection of entities is represented as a JSON object
containing a name/value pair named value. It MAY
contain context, count, nextLink, or deltaLink
annotations.
If present, the context
annotation MUST be the first name/value pair in the response.
The count name/value pair
represents the number of entities in the collection. If present and the streaming=true content type parameter is set, it MUST
come before the value name/value pair. If the
response represents a partial result, the count
name/value pair MUST appear in the first partial response, and it MAY appear in
subsequent partial
responses (in which case it may vary from response to response).
The value of the value name/value
pair is a JSON array where each element is representation of an entity or
a representation of an entity reference. An empty
collection is represented as an empty JSON array.
Functions or actions that are bound to this collection of
entities are advertised in the “wrapper object” in the same way as functions or actions
are advertised in the object representing a single entity.
The nextLink annotation MUST be
included in a response that represents a partial result.
Example 27:
{
"@context": "...",
"@count": 37,
"value": [
{
... },
{
... },
{
... }
],
"@nextLink": "...?$skiptoken=342r89"
}
An entity reference (see [OData-Protocol])
MAY take the place of an entity instance in a JSON payload, based on the client
request. It is serialized as a JSON object
that MUST contain the id of the referenced entity and
MAY contain the type
annotation and other custom annotations.
A collection of entity references is represented as a collection of entities, with entity
reference representations instead of entity representations as items in the
array value of the value name/value pair.
The outermost JSON object in a response MUST contain a context
annotation and MAY contain count, nextLink, or deltaLink
annotations.
Example 28: entity reference to order 10643
{
"@context": "http://host/service/$metadata#$ref",
"@id": "Orders(10643)"
}
Example 29: collection of entity references
{
"@context":
"http://host/service/$metadata#Collection($ref)",
"value": [
{
"@id": "Orders(10643)" },
{
"@id": "Orders(10759)" }
]
}
The non-format specific aspects of the delta handling are
described in the section “Requesting Changes” in [OData-Protocol].
Responses from a delta request are returned as a JSON
object. The JSON object MUST contain an array-valued property named value containing all added,
changed, or deleted entities, as well as added
or deleted links between entities, and MAY contain
additional, unchanged entities.
If the delta response contains a partial list of changes, it
MUST include a next link for the
client to retrieve the next set of changes.
The last page of a delta response SHOULD contain a delta link for retrieving subsequent
changes once the current set of changes has been applied to the initial set.
If the response from the delta link contains a count annotation, the
returned number MUST include all added, changed, or deleted entities to be
returned, as well as added or deleted links.
Example 30: a 4.01 delta response with five changes, in
order of occurrence
1. ContactName for customer 'BOTTM'
was changed to "Susan Halvenstern"
2. Order 10643 was removed
from customer 'ALFKI'
3. Order 10645 was added to
customer 'BOTTM'
4. The shipping information
for order 10643 was updated
5. Customer 'ANTON' was
deleted
{
"@context":"http://host/service/$metadata#Customers/$delta",
"@count":5,
"value":
[
{
"@id":"Customers('BOTTM')",
"ContactName":"Susan
Halvenstern"
},
{
"@context":"#Customers/$deletedLink",
"source":"Customers('ALFKI')",
"relationship":"Orders",
"target":"Orders(10643)"
},
{
"@context":"#Customers/$link",
"source":"Customers('BOTTM')",
"relationship":"Orders",
"target":"Orders(10645)"
},
{
"@context":"#Orders/$entity",
"@id":"Orders(10643)",
"ShippingAddress":{
"Street":"23 Tsawassen Blvd.",
"City":"Tsawassen",
"Region":"BC",
"PostalCode":"T2F 8M4"
},
},
{
"@context":"#Customers/$deletedEntity",
"@removed": {
"reason":"deleted"
},
"@id":"Customers('ANTON')"
}
],
"@deltaLink": "Customers?$expand=Orders&$deltatoken=8015"
}
14.1 Added/Changed Entity
Added or changed entities within a delta response are
represented as entities.
Added entities MUST include all available selected
properties and MAY include additional, unselected properties. Collection-valued
properties are treated as atomic values; any collection-valued properties
returned from a delta request MUST contain all current values for that
collection.
Changed entities MUST include all available selected properties
that have changed and MAY include additional properties.
If a property of an entity is dependent upon the property of
another entity within the expanded set of entities being tracked, then both the
change to the dependent property as well as the change to the principle
property or added/deleted link corresponding to the
change to the dependent property are returned in the delta response.
Entities that are not part of the entity set specified by
the context URL MUST include the context annotation to specify the
entity set of the entity, regardless of the specified metadata value.
Entities include annotations for selected navigation links
based on metadata.
OData 4.0 payloads MUST NOT include expanded navigation
properties inline; all changes MUST be represented as a flat array of added,
deleted, or changed entities, along with added or deleted links.
OData 4.01 delta payloads MAY include expanded navigation
properties inline. Related single entities are represented as either an added/changed entity, an entity reference, or the null value (if no entity
is related as the outcome of the change). Collection-valued navigation
properties are represented either as a delta representation or as a full
representation of the collection.
If the expanded navigation property represents a delta, it
MUST be represented as an array-valued annotation delta on the navigation property.
Added/changed entities or
entity references are
added to the collection. Deleted entities MAY be specified in a nested delta
representation to represent entities no longer part of the collection. If the
deleted entity specifies a reason as deleted, then the entity is both removed from the
collection and deleted, otherwise it is removed from the collection and only
deleted if the navigation property is a containment navigation property. The
array MUST NOT contain added or deleted links.
Example 31: 4.01 delta response customers with expanded
orders represented inline as a delta
1. Customer 'BOTTM':
a. ContactName was changed to
"Susan Halvenstern"
b. Order 10645 was added
2. Customer 'ALFKI':
a. Order 10643 was removed
3. Customer 'ANTON' was
deleted
{
"@context":"http://host/service/$metadata#Customers/$delta",
"@count":3,
"value":
[
{
"@id":"Customers('BOTTM')",
"ContactName":"Susan
Halvenstern",
"Orders@delta":[
{
"@id":"Orders(10645)"
}
]
},
{
"@id":"Customers('ALFKI')",
"Orders@delta":[
{
"@context":"#Orders/$deletedEntity",
"@removed": {
"reason": "changed"
},
"@id":"Orders(10643)"
}
]
},
{
"@context":"#Customers/$deletedEntity",
"@removed": {
"reason": "deleted"
},
"@id":"Customers('ANTON')"
}
],
"@deltaLink": "Customers?$expand=Orders&$deltatoken=8015"
}
If the expanded navigation property is a full representation
of the collection, it MUST be represented as an expanded navigation property,
and its array value represents the full set of entities related according to
that relationship and satisfying any specified expand options. Members of the
array MUST be represented as added/changed
entities or entity references and MUST NOT include added links, deleted links, or
deleted entities. Any entity not represented in the collection has
either been removed, deleted, or changed such that it no longer satisfies the
expand options in the defining query. In any case, clients SHOULD NOT receive
additional notifications for such removed entities.
14.2 Deleted
Entity
Deleted entities in JSON are returned as deleted-entity
objects. Delta responses MUST contain a deleted-entity object for each deleted
entity, including deleted expanded entities that are not related through a
containment navigation property. The service MAY additionally include expanded
entities related through a containment navigation property in which case it
MUST include those in any returned count of enumerated changes.
The representation of deleted-entity objects differs between
OData 4.0 and OData 4.01.
In OData 4.0 payloads the deleted-entity object MUST include
the following properties, regardless of the specified metadata value:
·
Annotation context – the context URL fragment
MUST be #{entity-set}/$deletedEntity, where {entity-set} is the entity set of the deleted entity
·
id – The id of the deleted entity (same as the id
returned or computed when calling GET on resource), which may be absolute or relative
In OData 4.0 payloads the deleted-entity object MAY include
the following optional property, regardless of the specified metadata value, and MAY include annotations:
·
reason – either deleted,
if the entity was deleted (destroyed), or changed
if the entity was removed from membership in the result (i.e., due to a data
change).
Example 32:
deleted entity in OData 4.0 response – note that id
is a property, not an annotation
{
"@context":"#Customers/$deletedEntity",
"reason":"deleted",
"id":"Customers('ANTON')"
}
In OData 4.01 payloads the deleted-entity object MUST
include the following properties, regardless of the specified metadata value:
·
Annotation removed, whose value is an
object that MAY contain a property named reason. If
present, the value of reason MUST be either deleted if the entity was deleted (destroyed), or changed if the entity was removed from membership in the
result either due to change in value such that the entity no longer matches the
defining query or because the entity was removed from the collection. The
object MAY include annotations, and clients SHOULD NOT error due to the
presence of additional properties that MAY be defined by future versions of
this specification. For ordered
payloads, the annotation removed MUST
immediately follow the context annotation, if present,
otherwise it MUST be the first property in the deleted entity.
·
Annotation id or all of the entity’s key
fields. The id annotation MUST appear if
any of the entity's key fields are omitted from the response or the
entity-id is not identical to the canonical URL of the entity.
For full metadata the context
annotation MUST be included. It also MUST be included if the entity set of the
deleted entity cannot be determined from the surrounding context.
The deleted-entity object MAY include additional properties
of the entity as well as annotations.
Example 33: deleted entity in OData 4.01 response with id annotation (prefixed with an @)
{
"@context":"#Customers/$deletedEntity",
"@removed":{
"reason":"deleted",
"@myannoation.deletedBy":"Mario"
},
"@id":"Customers('ANTON')"
}
Example 34: entity removed OData 4.01 response without id annotation and instead all key fields (ID is the single key field of Customer)
{
"@removed":{},
"ID":"ANTON"
}
14.3 Added Link
Links within a delta response are represented as link
objects.
Delta responses MUST contain a link object for each added
link that corresponds to a $expand
path in the initial request.
The link object MUST include the following properties, regardless of the specified metadata value, and MAY include annotations:
·
context – the context URL fragment
MUST be #{entity-set}/$link, where {entity-set} is the entity set containing the source
entity
·
source – The id of the entity from which the
relationship is defined, which may be absolute or relative
·
relationship – The path from the
source object to the navigation property which MAY traverse one or more complex
properties, type cast segments, or members of ordered collections
·
target – The id of the related entity, which may be
absolute or relative
14.4 Deleted
Link
Deleted links within a delta response are represented as
deleted-link objects.
Delta responses MUST contain a deleted-link object for each
deleted link that corresponds to a $expand
path in the initial request, unless either of the following is true:
·
The source or target entity has been deleted
·
The maximum cardinality of the related entity is one and there is
a subsequent link object that specifies the same source and relationship.
The deleted-link object MUST include the following properties, regardless of the specified metadata value, and MAY include annotations:
·
context – the context URL fragment
MUST be #{entity-set}/$deletedLink, where {entity-set} is the entity set containing the source
entity
·
source – The id of the entity from which the
relationship is defined, which may be absolute or relative
·
relationship – The path from the
source object to the navigation property which MAY traverse one or more complex
properties, type cast segments, or members of ordered collections
·
target – The id of the related entity for
multi-valued navigation properties, which may be absolute or relative. For delta payloads that do
not specify an OData-Version header value of 4.0, the target MAY be omitted
for single-valued navigation properties.
A bound function is advertised via a name/value pair where
the name is a hash (#) character followed by the
namespace- or alias-qualified name of the function. The namespace or alias MUST
be defined or the namespace referenced in the metadata document of the service,
see [OData-CSDLXML]..
A specific function overload can be advertised by appending the
parentheses-enclosed, comma-separated list of non-binding parameter names to
the qualified function name, see rule qualifiedFunctionName
in [OData-ABNF].
A function that is bound to a single structured type MAY be
advertised within the JSON object representing that structured type.
Functions that are bound to a collection MAY be advertised
within the JSON object containing the collection. If the collection is the top-level
response, the function advertisement name/value pair is placed next to the value name/value pair representing the collection. If the
collection is nested within an instance of a structured type, then in 4.01
payloads the name of the function advertisement is prepended with the name of
the collection-valued property and is placed next to the collection-valued
property, expanded navigation property,
or navigationLink annotation, if present. 4.0 payloads
MUST NOT advertise functions prefixed with property names.
If the function is available, the value of the advertisement
is an object. OData 4.01 services MAY advertise the non-availability of the function
with the value null.
If metadata=full is requested, each value object MUST
have at least the two name/value pairs title and target. It MAY contain annotations.
The order of the name/value pairs MUST be considered insignificant.
The target name/value pair
contains a URL. Clients MUST be able to invoke the function or the specific
function overload by passing the parameter values via query options for parameter aliases that are identical to the parameter name preceded by an at
(@) sign. Clients MUST check
if the obtained URL already contains a query part and appropriately precede the
parameters either with an ampersand (&) or a question mark (?).
The title name/value pair
contains the function or action title as a string.
If metadata=minimal is requested, the target name/value pair MUST be included if its value
differs from the canonical function or action URL.
Example 35: minimal representation of a function where all
overloads are applicable
{
"@context":
"http://host/service/$metadata#Employees/$entity",
"#Model.RemainingVacation":
{},
...
}
Example 36: full representation of a specific overload with
parameter alias for the Year
parameter
{
"@context":
"http://host/service/$metadata#Employees/$entity",
"#Model.RemainingVacation(Year)":
{
"title":
"Remaining vacation from year.",
"target":
"Employees(2)/RemainingVacation(Year=@Year)"
},
...
}
Example 37: full representation in a collection
{
"@context":
"http://host/service/$metadata#Employees",
"#Model.RemainingVacation":
{
"title":
"Remaining Vacation",
"target":
"Managers(22)/Employees/RemainingVacation"
},
"value": [ ... ]
}
Example 38:
full representation in a nested collection
{
"@context":
"http://host/service/$metadata#Employees/$entity",
"@type": "Model.Manager",
"ID":22,
...
"Employees#RemainingVacation": {
"title":
"RemainingVacation",
"target":
"Managers(22)/Employees/RemainingVacation"
}
}
A bound action is advertised via a name/value pair where the
name is a hash (#) character followed by the
namespace- or alias-qualified name of the action. The namespace or alias MUST
be defined or the namespace referenced in the metadata document of the service,
see [OData-CSDLXML]..
An action that is bound to a single structured type is advertised
within the JSON object representing that structured type.
Actions that are bound to a collection MAY be advertised
within the JSON object containing the collection. If the collection is the
top-level response, the action advertisement name/value pair is placed next to
the value name/value pair representing the collection.
If the collection is nested within an instance of a structured type, then in
4.01 payloads the name of the action advertisement is prepended with the name
of the collection-valued property and is placed next to the name/value pair
representing the collection-valued property, expanded navigation property, or navigationLink
annotation, if present. 4.0 payloads MUST NOT advertise actions prefixed with
property names.
If the action is available, the value of the advertisement
is an object. OData 4.01 services MAY advertise the non-availability of the
action with the value null.
If metadata=full is requested, each value object MUST
have at least the two name/value pairs title and target. It MAY contain annotations.
The order of these name/value pairs MUST be considered insignificant.
The target name/value pair
contains a bound function or action URL.
The title name/value pair
contains the function or action title as a string.
If metadata=minimal is requested, the target name/value pair MUST be included if its value
differs from the canonical function or action URL.
Example 39: minimal representation in an entity
{
"@context":
"http://host/service/$metadata#LeaveRequests/$entity",
"#Model.Approve":
{},
...
}
Example 40: full representation in an entity:
{
"@context":
"http://host/service/$metadata#LeaveRequests/$entity",
"#Model.Approve":
{
"title":
"Approve Leave Request",
"target":
"LeaveRequests(2)/Approve"
},
...
}
Example 41: full representation in a collection
{
"@context":
"http://host/service/$metadata#LeaveRequests",
"#Model.Approve":
{
"title":
"Approve All Leave Requests",
"target":
"Employees(22)/Model.Manager/LeaveRequests/Approve"
},
"value": [ ... ]
}
Example 42: full representation in a nested collection
{
"@context":
"http://host/service/$metadata#Employees/$entity",
"@type": "Model.Manager",
"ID":22,
...
"LeaveRequests#Model.Approve": {
"title":
"Approve All Leave Requests",
"target":
"Employees(22)/Model.Manager/LeaveRequests/Approve"
}
}
Action parameter values are encoded in a single JSON object
in the request body.
Each non-binding parameter value is encoded as a separate
name/value pair in this JSON object. The name is the name of the parameter. The
value is the parameter value in the JSON representation appropriate for its
type.
Any parameter values not specified in the JSON object are
assumed to have the null value.
Example 43:
{
"param1": 42,
"param2": {
"Street": "One Microsoft Way",
"Zip": 98052
},
"param3": [ 1, 42, 99 ],
"param4": null
}
In order to invoke an action with no non-binding parameters,
the client passes an empty JSON object in the body of the request. 4.01
Services MUST also support clients passing an empty request body for this case.
Annotations are an
extensibility mechanism that allows services and clients to include information
other than the raw data in the request or response. Annotations are used to
include control information in many payloads.
Annotations are name/value pairs that have an at (@) and a dot (.) as part of the
name. The part after the "at" sign (@) is
the annotation identifier. It consists of the namespace or alias
of the schema that defines the term, followed by a dot (.),
followed by the name of the term, optionally
followed by a hash (#) and a qualifier. The namespace or alias MUST
be defined in the metadata document, see [OData-CSDLXML]..
The namespace or alias odata is
reserved for future extensions of the protocol and format. Custom annotations
are annotations that have a namespace or alias that is different from odata.
Annotations can be applied to any name/value pair in a JSON
payload that represents a value of any type from the entity data model (see [OData-CSDLXML].).
Clients should never error due to an unexpected annotation in a JSON payload.
Annotations are always expressed as name/value pairs. For
entity data model constructs represented as JSON objects the annotation
name/value pairs are placed within the object; for constructs represented as
JSON arrays or primitives they are placed next to the annotated model
construct. When annotating a payload that represents
a single primitive or collection value, the annotations for the value appear next to the value property and are not
prefixed with a property name.
Example 44:
{
"@context": "http://host/service/$metadata#Customers",
"@com.example.customer.setkind": "VIPs",
"value": [
{
"@com.example.display.highlight": true,
"ID": "ALFKI",
"CompanyName@com.example.display.style": { "title": true,
"order": 1 },
"CompanyName": "Alfreds Futterkiste",
"Orders@com.example.display.style#simple": { "order": 2 }
}
]
}
When annotating a name/value pair
for which the value is represented as a JSON object, each annotation is placed
within the object and represented as a single name/value pair.
The name always starts with the "at" sign (@), followed by the annotation identifier.
The value MUST be an appropriate value for the annotation.
When annotating a name/value pair
for which the value is represented as a JSON array or primitive value, each
annotation that applies to this name/value pair MUST be represented as a single
name/value pair and placed immediately prior to the annotated name/value pair,
with the exception of the nextLink
annotation which can appear immediately before or after the collection it
annotates.
The name is the same as the name of the property or
name/value pair being annotated, followed by the “at” sign (@), followed by the annotation identifier.
The value MUST be an appropriate value for the annotation.
The error response MUST be a single JSON object. This object
MUST have a single name/value pair named error. The
value must be a JSON object.
This object MUST contain name/value pairs with the names code and message, and it MAY
contain name/value pairs with the names target,
details and innererror.
The value for the code name/value
pair is a language-independent string. Its value is a service-defined error
code. This code serves as a sub-status for the HTTP error code specified in the
response.
The value for the message
name/value pair MUST be a human-readable, language-dependent representation of
the error. The Content-Language header MUST contain
the language code from [RFC5646] corresponding to
the language in which the value for message is written.
The value for the target
name/value pair is the target of the particular error (for example, the name of
the property in error).
The value for the details
name/value pair MUST be an array of JSON objects that MUST contain name/value
pairs for code and message, and MAY contain a name/value
pair for target, as described
above.
The value for the innererror
name/value pair MUST be an object. The contents of this object are
service-defined. Usually this object contains information that will help debug
the service. The innererror name/value pair SHOULD only be used in development
environments in order to guard against potential security concerns around
information disclosure.
Error responses MAY contain annotations
in any of its JSON objects.
Example 45:
{
"error": {
"code": "501",
"message": "Unsupported functionality",
"target": "query",
"details": [
{
"code": "301",
"target": "$search",
"message": "$search query option not supported"
}
],
"innererror": {
"trace": [...],
"context": {...}
}
}
}
Implementations can add custom
annotations of the form @namespace.termname or property@namespace.termname to any
JSON object, where property MAY or MAY NOT match
the name of a name/value pair within the JSON object. However, the namespace
MUST NOT start with odata and SHOULD NOT be
required to be understood by the receiving party in order to correctly
interpret the rest of the payload as the receiving party MUST ignore unknown
annotations not defined in this version of the OData JSON Specification.
This specification raises no security issues.
This section is provided as a service to the application
developers, information providers, and users of OData version 4.0 giving some
references to starting points for securing OData services as specified. OData
is a REST-full multi-format service that depends on other services and thus
inherits both sides of the coin, security enhancements and concerns alike from
the latter.
For JSON-relevant security implications please cf. at least
the relevant subsections of [RFC7159] as starting
point.
Conforming clients MUST be prepared to consume a service
that uses any or all of the constructs defined in this specification. The
exception to this are the constructs defined in Delta
Response, which are only required for clients that request changes.
In order to
be a conforming consumer of the OData JSON format, a client or
service:
1. MUST
either:
a.
understand metadata=minimal (section 3.1.1) or
b.
explicitly specify metadata=none (section 3.1.3) or metadata=full (section 3.1.2)
in the request (client)
2. MUST be
prepared to consume a response with full metadata
3. MUST be
prepared to receive all data types (section 7.1)
a. defined
in this specification (client)
b. exposed
by the service (service)
4. MUST
interpret all odata annotations defined according
to the OData-Version header of
the payload (section 0)
5. MUST be
prepared to receive any annotations, including custom annotations and odata annotations
not defined in the OData-Version
header of the payload (section 20)
6. MUST NOT
require streaming=true in the Content-Type header (section 4.4)
7. MUST be a
conforming consumer of the OData 4.0 JSON format, for payloads with an OData-Version header value of 4.0.
a. MUST
accept the odata. prefix, where
defined, on format parameters and control information
b. MUST
accept the # prefix in @odata.type
values
c. MUST
be prepared to handle binding through the use of the @odata.bind property in payloads
to a PATCH, PUT, or POST
request
d. MUST
accept TargetId within in a deleted link for a relationship with
a maximum cardinality of one
e. MUST
accept the string values INF, -INF, and Nan for numeric value exceptions for single and double
values
f.
MUST support property annotations that appear immediately before or
after the property they annotate
8. MAY be a
conforming consumer of the OData 4.01 JSON format, for payloads with an OData-Version header value of 4.01.
a. MUST
be prepared to interpret control information
with or without the odata.
prefix
b. MUST
be prepared for @odata.type primitive values with
or without the # prefix
c. MUST
be prepared to handle binding through inclusion of an entity reference within a
collection-valued navigation property in the body of a PATCH, PUT,
or POST request
d. MUST
be prepared for TargetId to be
included or omitted in a deleted link
for a relationship with a maximum cardinality of one
e. MUST
be prepared to interpret the Core.NumericValueException
annotation, defined in [OData-VocCore], for
numeric value exceptions
f.
MUST be prepared to handle related entities inline within
a delta payload as
well as a nested delta representation for the collection
g. MUST
be prepared to handle decimal values written in exponential notation
In order to
be a conforming producer of the OData JSON format, a client or
service:
9. MUST
support generating OData 4.0 JSON compliant payloads with an OData-Version header value of 4.0.
a. MUST
NOT omit the odata. prefix from format parameters or control information
b. MUST
NOT omit the # prefix from @odata.type values
c. MUST
NOT include entity values or entity references within a collection-valued
navigation property in the body of a PATCH,
PUT, or POST request
d. MUST
NOT return decimal values written in exponential notation unless the ExponentialDecimals
format parameter is specified.
e. MUST
NOT advertise available actions or functions using name/value pairs prefixed
with a property name
f.
MUST NOT return a null value for name/value pairs representing actions
or functions that are not available
g. SHOULD
represent numeric value exceptions for single and double values using the
string property values INF, -INF, and Nan
h. MAY
include the Core.NumericValueException
annotation, defined in [OData-VocCore], for any
numeric value exception
10. MAY support generating OData
4.01 JSON compliant payloads for requests with an OData-Version header value of 4.01.
a. MUST
return property annotations immediately before the property they annotate
b. SHOULD
omit the odata. prefix from format parameters and odata control information
c. SHOULD
omit the # prefix from @type
primitive values
d. MAY
include inline related entities or nested delta collections within a delta
payload
e. MAY
include TargetId within a deleted link for a relationship with
a maximum cardinality of 1
f.
MAY return decimal values written in exponential notation
g. MUST
represent numeric value exceptions using the Core.NumericValueException annotation,
defined in [OData-VocCore], for any numeric value
exception
h. MUST
NOT use the string property values INF,
-INF, and Nan for numeric value exceptions
In addition, in order to conform to the OData JSON format, a
service:
11. MUST comply with one of the
conformance levels defined in [OData-Protocol]
12. MUST support the application/json media type in the Accept header (section
3)
13. MUST return well-formed JSON
payloads
14. MUST support odata.metadata=full (section 3.1.2)
15. MUST include the odata.nextLink annotation in partial results for entity
collections (section 4.5.5)
16. MUST support entity
instances with external metadata (section 4.5.1)
17. MUST support properties with
externally defined data types (section 4.5.3)
18. MUST NOT violate any other
aspects of this OData JSON specification
19. SHOULD support the $format system query option (section 3)
20. MAY support the odata.streaming=true parameter in the Accept header (section 4.4)
21. MAY return full metadata
regardless of odata.metadata (section 3.1.2)
22. MUST NOT omit null or
default values unless the omit-values preference is
specified in the Prefer request header and the omit-values
preference is included in the Preference-Applied
response header
23. MUST return OData JSON
4.0-compliant responses for requests with an OData-MaxVersion
header value of 4.0
24. MUST support OData JSON
4.0-compliant payloads in requests with an OData-Version
header value of 4.0
25. MUST support returning, in
the final response to an asynchronous request, the application/json
payload that would have been returned had the operation completed
synchronously, wrapped in an application/http message
In addition, in order to comply with the OData 4.01 JSON
format, a service:
26. SHOULD return the OData JSON
4.01 format for requests with an OData-MaxVersion
header value of 4.01
27. MUST support the OData JSON
4.01 format in request payloads for requests with an OData-Version
header value of 4.01
28. MUST honor the odata.etag annotation within PUT, PATCH or DELETE payloads, if specified
29. MUST support returning, in
the final response to an asynchronous request, the application/json
payload that would have been returned had the operation completed synchronously
Appendix A.
Acknowledgments
The contributions of the OASIS OData Technical Committee members,
enumerated in [OData-Protocol], are gratefully
acknowledged.
|
Revision
|
Date
|
Editor
|
Changes Made
|
|
Working Draft 01
|
2016-06-22
|
Michael Pizzo
Ralf Handl
|
Import material from OData 4.0 Errata 3 JSON document and
initial application of 4.01 features
|
|
Committee Specification Draft 01
|
2016-12-08
|
Michael Pizzo
Ralf Handl
|
Integrated 4.01 features
|
