Merge branch 'feature/link-header-extension' into 'master' (b091d6a8) · Commits · DATA - Data Solutions / Specifications / TS 104 175

md/annex-c.md

+20 −18

md/clause-10.md

+20 −15

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	@@ -1646,20 +1646,23 @@ Figure: Retrieve Entity use case
	["application/ld+json"]{.HTML-Code}, return a JSON-LD object representing the		["application/ld+json"]{.HTML-Code}, return a JSON-LD object representing the
	Entity as mandated by clause 5.2.6.4.1 and containing only the Attributes		Entity as mandated by clause 5.2.6.4.1 and containing only the Attributes
	requested (if present).		requested (if present).
	- If the Prefer Header [n.14] is set to		- If the [Prefer]{.HTML-Code} Header [n.14] is set to
	["ngsi-ld=<version>"]{.HTML-Code} then the ContextBroker shall		["ngsi-ld=<version>"]{.HTML-Code} then the ContextBroker shall
	endeavour to amend the JSON-LD object to conform to the specified version of		endeavour to amend the JSON-LD object to conform to the specified version of
	the NGSI-LD specification as mandated in clause 9.5.3, and return a		the NGSI-LD specification as mandated in clause 9.5.3, and return a
	Preference-Applied Header set to		[Preference-Applied]{.HTML-Code} Header set to
	["ngsi-ld=<conformant-version>"]{.HTML-Code} in the response.		["ngsi-ld=<conformant-version>"]{.HTML-Code} in the response.

	- If the Accept Header is set to ["application/geo+json"]{.HTML-Code}, a GeoJSON		- If the [Accept]{.HTML-Code} Header is set to
	_Feature_ object representing the entity as mandated by clause 5.2.6.11.1 and		["application/geo+json"]{.HTML-Code}, a GeoJSON _Feature_ object representing
	containing only the Attributes requested (if present):		the entity as mandated by clause 5.2.6.11.1 and containing only the Attributes
	- If the Prefer Header is omitted or set to ["body=ld+json"]{.HTML-Code} then		requested (if present):
	the _Feature_ object will also contain an _`@context`_ field.		- If the [Prefer]{.HTML-Code} Header is omitted or set to
	- If the Prefer Header is set to ["body=json"]{.HTML-Code} the _`@context`_ is		["body=ld+json"]{.HTML-Code} then the _Feature_ object will also contain an
	set as a Link Header and removed from the Feature object.		_`@context`_ field.
			- If the [Prefer]{.HTML-Code} Header is set to ["body=json"]{.HTML-Code} the
			_`@context`_ is set as a [Link]{.HTML-Code} Header and removed from the
			Feature object.

	#### 10.4.2.5 Output data		#### 10.4.2.5 Output data

	@@ -1973,21 +1976,23 @@ If the execution of the operation is limited to the local scope (see clause
	["application/ld+json",]{.HTML-Code} a JSON-LD array is returned, representing		["application/ld+json",]{.HTML-Code} a JSON-LD array is returned, representing
	the Entities as mandated by clause 5.2.6.4.1 and containing only the		the Entities as mandated by clause 5.2.6.4.1 and containing only the
	Attributes requested (if present).		Attributes requested (if present).
	- If the Prefer Header [n.14] is set to		- If the [Prefer]{.HTML-Code} Header [n.14] is set to
	["ngsi-ld=<version>"]{.HTML-Code} then the ContextBroker shall		["ngsi-ld=<version>"]{.HTML-Code} then the ContextBroker shall
	endeavour to amend the elements of the JSON-LD array to conform to the		endeavour to amend the elements of the JSON-LD array to conform to the
	specified version of the NGSI-LD specification as mandated in clause 9.5.3,		specified version of the NGSI-LD specification as mandated in clause 9.5.3,
	and return a Preference-Applied Header set to		and return a [Preference-Applied]{.HTML-Code} Header set to
	["ngsi-ld=<conformant-version>"]{.HTML-Code} in the response.		["ngsi-ld=<conformant-version>"]{.HTML-Code} in the response.

	- If the Accept Header is set to ["application/geo+json",]{.HTML-Code} the		- If the Accept Header is set to ["application/geo+json",]{.HTML-Code} the
	response shall be a GeoJSON _FeatureCollection_ as mandated by clause		response shall be a GeoJSON _FeatureCollection_ as mandated by clause
	5.2.6.11.2, with each _Feature_ within the _FeatureCollection_ containing only		5.2.6.11.2, with each _Feature_ within the _FeatureCollection_ containing only
	the Attributes requested (if present):		the Attributes requested (if present):
	- If the Prefer Header is omitted or set to ["body=ld+json"]{.HTML-Code} then		- If the [Prefer]{.HTML-Code} Header is omitted or set to
	the _FeatureCollection_ will also contain an _`@context`_ field.		["body=ld+json"]{.HTML-Code} then the _FeatureCollection_ will also contain
	- If the Prefer Header is set to ["body=json]{.HTML-Code}" the _`@context`_ is		an _`@context`_ field.
	sent as a Link Header and removed from the _FeatureCollection_ object.		- If the [Prefer]{.HTML-Code} Header is set to ["body=json]{.HTML-Code}" the
			_`@context`_ is sent as a [Link]{.HTML-Code} Header and removed from the
			_FeatureCollection_ object.

	#### 10.4.3.5 Output data		#### 10.4.3.5 Output data

md/clause-13.md

+5 −5

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	@@ -18,11 +18,11 @@ Consequently, the broker has no ability to cache _`@contexts`_ that arrive to it
	as embedded parts within the NGSI-LD documents, since they are not uniquely		as embedded parts within the NGSI-LD documents, since they are not uniquely
	(and implicitly) identified by any URL; [Context Brokers]{.HTML-Keyboard} only		(and implicitly) identified by any URL; [Context Brokers]{.HTML-Keyboard} only
	cache _`@contexts`_ that are referred to by means of explicit URLs (either in		cache _`@contexts`_ that are referred to by means of explicit URLs (either in
	the HTTP Link header or as URLs in the payload body). Thus, the **recommended		the HTTP [Link]{.HTML-Code} header or as URLs in the payload body). Thus, the
	best-practice, in order to exploit caching, is that clients do not embed their		**recommended best-practice, in order to exploit caching, is that clients do not
	user _`@contexts`_ into their NGSI-LD documents**; instead clients should		embed their user _`@contexts`_ into their NGSI-LD documents**; instead
	explicitly host their user _`@contexts`_ at their premises, or use the broker's		clients should explicitly host their user _`@contexts`_ at their premises, or
	capability to host user _`@contexts`_ on their behalf.		use the broker's capability to host user _`@contexts`_ on their behalf.

	When an external _`@context`_ is stored, either explicitly upon a client's		When an external _`@context`_ is stored, either explicitly upon a client's
	request or implicitly downloaded for caching purposes, the Context Broker		request or implicitly downloaded for caching purposes, the Context Broker

md/clause-5.md

+4 −4

Original line number	Original line	Diff line number	Diff line
	@@ -3811,14 +3811,14 @@ following terms:
	mapping the Property name with its Property Identifier (URI).		mapping the Property name with its Property Identifier (URI).

	Whereas the Core NGSI-LD _`@context`_ contains JSON-LD Scoped Contexts, the user		Whereas the Core NGSI-LD _`@context`_ contains JSON-LD Scoped Contexts, the user
	_`@context`_ shall not contain JSON-LD Scoped Contexts (see [n.8],		_`@context`_ shall not contain JSON-LD Scoped Contexts (see [n.8], Section
	Clause+++root.3.2.1), as described in Clause+++clause-8+++8.2.4, because this		4.1.8), as described in Clause+++clause-8+++8.2.4, because this would enable
	would enable overwriting terms defined in the Core NGSI-LD _`@context`_.		overwriting terms defined in the Core NGSI-LD _`@context`_.

	Depending on the binding, the _`@context`_ may not just be provided embedded		Depending on the binding, the _`@context`_ may not just be provided embedded
	with the rest of the JSON content, but there could be other options. For		with the rest of the JSON content, but there could be other options. For
	example, in the HTTP binding, the _`@context`_ can be made available through a		example, in the HTTP binding, the _`@context`_ can be made available through a
	Link header (see Clause+++clause-6+++6.2.4).		[Link]{.HTML-Code} header (see [n.8], Section 6.2).

	#### 5.3.2.2 Entities Normalized		#### 5.3.2.2 Entities Normalized

md/clause-8.md

+7 −6

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	@@ -88,12 +88,13 @@ operations (Clause+++clause-10+++10.4.3), the _`@context`_ used to perform URI
	expansion and compaction shall be the one provided by the request.		expansion and compaction shall be the one provided by the request.

	In case of HTTP binding via GET (see [i.16] ~clause 7.2.3.1) of the "Query		In case of HTTP binding via GET (see [i.16] ~clause 7.2.3.1) of the "Query
	Entities" operation, this means using the JSON-LD Link Header as described by		Entities" operation, this means using the JSON-LD [Link]{.HTML-Code} Header as
	the JSON-LD specification [n.8], section 6.2. In case of HTTP binding via POST		described by the JSON-LD specification [n.8], section 6.2. In case of HTTP
	(see [i.16] ~clause 7.12.3.1), of the "Query Entities" operation, this means		binding via POST (see [i.16] ~clause 7.12.3.1), of the "Query Entities"
	giving the _`@context`_ either via Link Header or within the payload body,		operation, this means giving the _`@context`_ either via [Link]{.HTML-Code}
	depending on the Content-Type Header being ["application/json"]{.HTML-Code} or		Header or within the payload body, depending on the Content-Type Header being
	["application/ld+json"]{.HTML-Code}, respectively.		["application/json"]{.HTML-Code} or ["application/ld+json"]{.HTML-Code},
			respectively.

	It is important to warn users that updating a _`@context`_ could lead to		It is important to warn users that updating a _`@context`_ could lead to
	behaviour that might be perceived as inconsistent. If, for instance, a fully		behaviour that might be perceived as inconsistent. If, for instance, a fully

Original line number	Original line	Diff line number	Diff line
	@@ -1106,10 +1106,10 @@ level of the graph only.
	Below is an example, where temporal evolution of the speed of the car is		Below is an example, where temporal evolution of the speed of the car is
	provided by two different sources. As both may be relevant at the same time,		provided by two different sources. As both may be relevant at the same time,
	there are two individual attribute instances for speed; each is identified by a		there are two individual attribute instances for speed; each is identified by a
	_`datasetId`_ and both instances are represented in an array. The combination of an		_`datasetId`_ and both instances are represented in an array. The combination of
	Attribute's _`datasetId`_ and the _`instanceId`_ associated to each value enables		an Attribute's _`datasetId`_ and the _`instanceId`_ associated to each value
	modification of a particular instance value without affecting instances from other		enables modification of a particular instance value without affecting instances
	sources.		from other sources.

	```json		```json
	{		{
	@@ -2168,7 +2168,7 @@ been compacted, as the Core _`@context`_ is always considered to be implicitly
	present if not specified explicitly (and that is why it is included in the		present if not specified explicitly (and that is why it is included in the
	JSON-LD response, as mandated by the specification).		JSON-LD response, as mandated by the specification).

	## C.7 Link header utilization clarifications		## C.7 JSON-LD Link header utilization clarifications

	The JSON-LD Specification [n.8] states clearly that **only one HTTP Link		The JSON-LD Specification [n.8] states clearly that **only one HTTP Link
	header** with the link relationship		header** with the link relationship
	@@ -2178,8 +2178,8 @@ using the NGSI-LD API. The main implication is that if the _`@context`_ is a
	compound one, i.e. an _`@context`_ which references multiple individual		compound one, i.e. an _`@context`_ which references multiple individual
	_`@context`_, served by resources behind different URIs, then a wrapper		_`@context`_, served by resources behind different URIs, then a wrapper
	_`@context`_ has to be created and hosted. The final aim is that only one		_`@context`_ has to be created and hosted. The final aim is that only one
	_`@context`_ is referenced from the JSON-LD Link header. This can be illustrated		_`@context`_ is referenced from the JSON-LD [Link]{.HTML-Code} header. This can
	with an example:		be illustrated with an example:

	Imagine that it is desired to create an Entity providing _`@context`_ terms		Imagine that it is desired to create an Entity providing _`@context`_ terms
	which are defined in two different JSON-LD _`@context`_ resources:		which are defined in two different JSON-LD _`@context`_ resources:
	@@ -2187,8 +2187,9 @@ which are defined in two different JSON-LD _`@context`_ resources:
	- _`http://example.org/vehicle/v1/vehicle-context.jsonld`_		- _`http://example.org/vehicle/v1/vehicle-context.jsonld`_
	- _`https://schema.org`_		- _`https://schema.org`_

	If a developer wants to reference these two _`@context`_ resources from a Link		If a developer wants to reference these two _`@context`_ resources from a
	header, a wrapper _`@context`_ can be easily created as follows:		JSON-LD [Link]{.HTML-Code} header, a wrapper _`@context`_ can be easily created
			as follows:

	```json		```json
	{		{
	@@ -2200,12 +2201,13 @@ header, a wrapper _`@context`_ can be easily created as follows:
	}		}

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