JSON-LD Framing allows developers to query by example and force a specific tree layout to a JSON-LD document.
This specification describes a superset of the features defined in JSON-LD Framing 1.0 [JSON-LD10-FRAMING] and, except where noted, the algorithms described in this specification are fully compatible with documents created using the previous community standard.
Status of This DocumentThis section describes the status of this document at the time of its publication. Other documents may supersede this document. A list of current W3C publications and the latest revision of this technical report can be found in the W3C technical reports index at https://www.w3.org/TR/.
This document has been developed by the JSON-LD Working Group and was derived from the JSON-LD Community Group's Final Report.
There is a live JSON-LD playground that is capable of demonstrating the features described in this document.
This document was published by the JSON-LD Working Group as a Recommendation.
GitHub Issues are preferred for discussion of this specification. Alternatively, you can send comments to our mailing list. Please send them to public-json-ld-wg@w3.org (archives).
Please see the Working Group's implementation report.
This document has been reviewed by W3C Members, by software developers, and by other W3C groups and interested parties, and is endorsed by the Director as a W3C Recommendation. It is a stable document and may be used as reference material or cited from another document. W3C's role in making the Recommendation is to draw attention to the specification and to promote its widespread deployment. This enhances the functionality and interoperability of the Web.
This document was produced by a group operating under the W3C Patent Policy. W3C maintains a public list of any patent disclosures made in connection with the deliverables of the group; that page also includes instructions for disclosing a patent. An individual who has actual knowledge of a patent which the individual believes contains Essential Claim(s) must disclose the information in accordance with section 6 of the W3C Patent Policy.
This document is governed by the 1 March 2019 W3C Process Document.
Set of DocumentsThis document is one of three JSON-LD 1.1 Recommendations produced by the JSON-LD Working Group:
Table of ContentsThis section is non-normative.
JSON-LD is a lightweight syntax to serialize Linked Data [LINKED-DATA] in JSON [RFC8259]. Its design allows existing JSON to be interpreted as Linked Data with minimal changes. As with other representations of Linked Data which describe directed graphs, a single directed graph can have many different serializations, each expressing exactly the same information. Developers typically work with trees, represented as JSON objects. While mapping a graph to a tree can be done, the layout of the end result must be specified in advance. A Frame can be used by a developer on a JSON-LD document to specify a deterministic layout for a graph.
Using delimiters around a chunk of data is known as "framing". JSON-LD uses JSON delimiters such as { and } to separate statements about a particular subject. JSON-LD also allows subjects to reference other subjects through the use of their identifiers, expressed as strings.
However, given that JSON-LD represents one or more graphs of information, there is more than one way to frame the statements about several related subjects into a whole document. In fact, a graph of information can be thought of as a long list of independent statements (aka triples) that are not bundled together in any way.
The JSON-LD Framing API enables a developer to specify exactly how they would like data to be framed, such that statements about a particular subject are bundled together, delimited via { and }, and such that the subjects they relate to "nest" into a particular tree structure that matches what their application expects.
This section is non-normative.
This document is a detailed specification for a serialization of Linked Data in JSON. The document is primarily intended for the following audiences:
A companion document, the JSON-LD 1.1 specification [JSON-LD11], specifies the grammar of JSON-LD documents.
To understand the basics in this specification you must first be familiar with JSON, which is detailed in [RFC8259]. You must also understand the JSON-LD 1.1 Syntax specification [JSON-LD11], which is the base syntax used by all of the algorithms in this document, and the JSON-LD 1.1 API [JSON-LD11-API]. To understand the API and how it is intended to operate in a programming environment, it is useful to have working knowledge of the JavaScript programming language [ECMASCRIPT] and WebIDL [WEBIDL]. To understand how JSON-LD maps to RDF, it is helpful to be familiar with the basic RDF concepts [RDF11-CONCEPTS].
This document can highlight changes since the JSON-LD 1.0 version. Select to changes.
1.2 ContributingThis section is non-normative.
There are a number of ways that one may participate in the development of this specification:
This section is non-normative.
The following typographic conventions are used in this specification:
markup
markup definition reference
markup external definition reference
Note
Notes are in light green boxes with a green left border and with a "Note" header in green. Notes are always informative.
Examples are in light khaki boxes, with khaki left border, and with a numbered "Example" header in khaki. Examples are always informative. The content of the example is in monospace font and may be syntax colored. Examples may have tabbed navigation buttons to show the results of transforming an example into other representations.1.4 Terminology
This document uses the following terms as defined in external specifications and defines terms specific to JSON-LD.
Terms imported from Other SpecificationsTerms imported from ECMAScript Language Specification [ECMASCRIPT], The JavaScript Object Notation (JSON) Data Interchange Format [RFC8259], Infra Standard [INFRA], and Web IDL [WEBIDL]
true and false that are used to express one of two possible states.
In the internal representation a JSON object is described as a map (see [INFRA]), composed of entries with key/value pairs.
In the Application Programming Interface, a map is described using a [WEBIDL] record.
@context where the value, or the @id of the value, is null, explicitly decouples a term's association with an IRI. A map entry in the body of a JSON-LD document whose value is null has the same meaning as if the map entry was not defined. If @value, @list, or @set is set to null in expanded form, then the entire JSON object is ignored.
true, or false.
Terms imported from Internationalized Resource Identifiers (IRIs) [RFC3987]
@type, and values of terms defined to be vocabulary relative are resolved relative to the vocabulary mapping, not the base IRI.
Terms imported from RDF 1.1 Concepts and Abstract Syntax [RDF11-CONCEPTS], RDF Schema 1.1 [RDF-SCHEMA], and Linked Data Design Issues [LINKED-DATA]
_:.
_:.
rdf:langString, an optional language tag.
Note
The use of
blank node identifiersto label properties is obsolete, and may be removed in a future version of JSON-LD.
Also, see predicate in [RDF11-CONCEPTS].@direction key whose value must be one of the strings "ltr", "rtl", or null. See the Context Definitions section of JSON-LD 1.1 for a normative description.
@default key.
true or false, a typed value, or a language-tagged string. It represents an RDF literal.
@id key.
@version entry in a context, publishers can ensure that processors conformant with JSON-LD 1.0 [JSON-LD10] will not accidentally process JSON-LD 1.1 documents, possibly creating a different output. The API provides an option for setting the processing mode to json-ld-1.0, which will prevent JSON-LD 1.1 features from being activated, or error if @version entry in a context is explicitly set to 1.1. This specification extends JSON-LD 1.0 via the json-ld-1.1 processing mode.
@context entry. It has the same form as an embedded context. When the term is used as a type, it defines a type-scoped context, when used as a property it defines a property-scoped context.
@value entry. See the Value Objects section of JSON-LD 1.1 for a normative description.
@vocab key whose value must be an IRI, a compact IRI, a term, or null. See the Context Definitions section of JSON-LD 1.1 for a normative description.
The Following terms are used within specific algorithms.
true, and the reverse flag defaults to false.
@graph entry, or only if required to represent multiple node objects.
This specification adds a number of keywords (framing keywords) to the ones defined in the JSON-LD 1.1 Syntax specification [JSON-LD11]:
@default
@embed
@embed as the following:
@always
@once
@embed nor object embed flag is specified.
Note
The specific
node objectchosen to embed depends on ordering. If the
orderedflag is
true
, this will be the first
node objectencountered, otherwise, it may be any node object.
@never
Any other value for @embed is invalid and indicates that an invalid @embed value error has been detected and processing is aborted.
@explicit
@null
null should be returned, which would otherwise be removed when Compacting.
@omitDefault
@requireAll
All JSON-LD tokens and keywords are case-sensitive.
2. FeaturesThis section is non-normative.
JSON-LD 1.1 introduces new features that are compatible with JSON-LD 1.0 [JSON-LD10], but if processed by a JSON-LD 1.0 processor may produce different results. Processors default to json-ld-1.1, unless the processingMode API option is explicitly set to json-ld-1.0. Publishers are encouraged to use the @version map entry within a context set to 1.1 to ensure that JSON-LD 1.0 processors will not misinterpret JSON-LD 1.1 features.
This section is non-normative.
Framing is used to shape the data in a JSON-LD document, using an example frame document which is used to both match the flattened data and show an example of how the resulting data should be shaped. Matching is performed by using properties present in in the frame to find objects in the data that share common values. Matching can be done either using all properties present in the frame, or any property in the frame. By chaining together objects using matched property values, objects can be embedded within one another.
A frame also includes a context, which is used for compacting the resulting framed output.
For example, assume the following JSON-LD frame:
{
"@context": {"@vocab": "http://example.org/"},
"@type": "Library",
"contains": {
"@type": "Book",
"contains": {
"@type": "Chapter"
}
}
}This frame document describes an embedding structure that would place objects with type Library at the top, with objects of type Book that were linked to the library object using the contains property embedded as property values. It also places objects of type Chapter within the referencing Book object as embedded values of the Book object.
When using a flattened set of objects that match the frame components:
{
"@context": {
"@vocab": "http://example.org/",
"contains": {"@type": "@id"}
},
"@graph": [{
"@id": "http://example.org/library",
"@type": "Library",
"location": "Athens",
"contains": "http://example.org/library/the-republic"
}, {
"@id": "http://example.org/library/the-republic",
"@type": "Book",
"creator": "Plato",
"title": "The Republic",
"contains": "http://example.org/library/the-republic#introduction"
}, {
"@id": "http://example.org/library/the-republic#introduction",
"@type": "Chapter",
"description": "An introductory chapter on The Republic.",
"title": "The Introduction"
}]
}The Frame Algorithm can create a new document which follows the structure of the frame:
{
"@context": {"@vocab": "http://example.org/"},
"@id": "http://example.org/library",
"@type": "Library",
"location": "Athens",
"contains": {
"@id": "http://example.org/library/the-republic",
"@type": "Book",
"creator": "Plato",
"title": "The Republic",
"contains": {
"@id": "http://example.org/library/the-republic#introduction",
"@type": "Chapter",
"description": "An introductory chapter on The Republic.",
"title": "The Introduction"
}
}
}If processing mode is not json-ld-1.0, or the omit graph flag is true, the top-level @graph entry may be omitted.
{
"@context": {"@vocab": "http://example.org/"},
"@id": "http://example.org/library",
"@type": "Library",
"location": "Athens",
"contains": {
"@id": "http://example.org/library/the-republic",
"@type": "Book",
"creator": "Plato",
"title": "The Republic",
"contains": {
"@id": "http://example.org/library/the-republic#introduction",
"@type": "Chapter",
"description": "An introductory chapter on The Republic.",
"title": "The Introduction"
}
}
}The Framing Algorithm does this by first expanding both the input frame and document. It then creates a map of flattened subjects. The outer-most node object within the frame is used to match objects in the map, in this case looking for node objects which have an @type of Library, and a contains property with another frame used to match values of that property. The input document contains exactly one such node object. The value of contains also has a node object, which is then treated as a frame to match the set of subjects which are contains values of the Library object, and so forth.
This section is non-normative.
In addition to matching on types, a frame can match on one or more properties.
For example, the following frame selects object based on property values, rather than @type.
{
"@context": {"@vocab": "http://example.org/"},
"location": "Athens",
"contains": {
"title": "The Republic",
"contains": {
"title": "The Introduction"
}
}
}
This will generate the same framed results as when selecting on @type, as the property values are unique to each node object.
{
"@context": {"@vocab": "http://example.org/"},
"@id": "http://example.org/library",
"@type": "Library",
"location": "Athens",
"contains": {
"@id": "http://example.org/library/the-republic",
"@type": "Book",
"creator": "Plato",
"title": "The Republic",
"contains": {
"@id": "http://example.org/library/the-republic#introduction",
"@type": "Chapter",
"description": "An introductory chapter on The Republic.",
"title": "The Introduction"
}
}
}See § 2.3.5 Require all flag to see how matching can be restricted to match node objects containing all, versus any such listed property.
2.1.2 Wildcard MatchingThis section is non-normative.
The empty map ({}) is used as a wildcard, which will match a property if it exists in a target node object, independent of any specific value.
For example, the following frame selects object based on property wildcarding, rather than @type.
{
"@context": {"@vocab": "http://example.org/"},
"location": {},
"contains": {
"creator": {},
"contains": {
"description": {}
}
}
}
This will generate the same framed results as when selecting on @type, as the matched properties are distinct to each node object.
{
"@context": {"@vocab": "http://example.org/"},
"@id": "http://example.org/library",
"@type": "Library",
"location": "Athens",
"contains": {
"@id": "http://example.org/library/the-republic",
"@type": "Book",
"creator": "Plato",
"title": "The Republic",
"contains": {
"@id": "http://example.org/library/the-republic#introduction",
"@type": "Chapter",
"description": "An introductory chapter on The Republic.",
"title": "The Introduction"
}
}
}This section is non-normative.
The empty array ([]) is used for match none, which will match a node object only if a property does not exist in a target node object.
For example, the following frame selects object based on the absence of properties, rather than @type.
{
"@context": {"@vocab": "http://example.org/"},
"creator": [],
"title": [],
"contains": {
"location": [],
"description": [],
"contains": {
"location": []
}
}
}
This will generate the same framed results as when selecting on @type, the property that is excluded uniquely identifies each node object. Note that additional properties with the value null are added for those properties explicitly excluded.
{
"@context": {"@vocab": "http://example.org/"},
"@id": "http://example.org/library",
"@type": "Library",
"location": "Athens",
"creator": null,
"title": null,
"contains": {
"@id": "http://example.org/library/the-republic",
"@type": "Book",
"creator": "Plato",
"description": null,
"location": null,
"title": "The Republic",
"contains": {
"@id": "http://example.org/library/the-republic#introduction",
"@type": "Chapter",
"description": "An introductory chapter on The Republic.",
"location": null,
"title": "The Introduction"
}
}
}This section is non-normative.
Frames can be matched based on the presence of specific property values. These values can themselves use wildcards, to match on a specific or set of values, language tags, types, or base direction.
For an example, we'll use an multilingual version of the library example with more complex value representations.
{
"@context": {
"@vocab": "http://example.org/",
"contains": {"@type": "@id"}
},
"@graph": [{
"@id": "http://example.org/library",
"@type": "Library",
"location": [
{"@value": "Athens", "@language": "en"},
{"@value": "Αθήνα", "@language": "grc"},
{"@value": "Athína", "@language": "el-Latn"}
],
"contains": "http://example.org/library/the-republic"
}, {
"@id": "http://example.org/library/the-republic",
"@type": "Book",
"creator": [
{"@value": "Plato", "@language": "en"},
{"@value": "Πλάτων", "@language": "grc"},
{"@value": "Plátōn", "@language": "el-Latn"}
],
"title": [
{"@value": "The Republic", "@language": "en"},
{"@value": "Πολιτεία", "@language": "grc"},
{"@value": "Res Publica", "@language": "el-Latn"}
],
"contains": "http://example.org/library/the-republic#introduction"
}, {
"@id": "http://example.org/library/the-republic#introduction",
"@type": "Chapter",
"description": "An introductory chapter on The Republic.",
"title": "The Introduction"
}]
}By matching on an attribute of a value, we can match frames having that attribute, and limit results to property values that match. In this case, we'll frame the Library and Book objects on values only in latinized Greek (el-Latn):
{
"@context": {"@vocab": "http://example.org/"},
"location": {"@value": {}, "@language": "el-Latn"},
"contains": {
"creator": {"@value": {}, "@language": "el-Latn"},
"title": {"@value": {}, "@language": "el-Latn"},
"contains": {
"title": "The Introduction"
}
}
}
This generates the following framed results:
Example 14: Framed library objects with wildcard matching{
"@context": {"@vocab": "http://example.org/"},
"@id": "http://example.org/library",
"@type": "Library",
"location": {"@value": "Athína", "@language": "el-Latn"},
"contains": {
"@id": "http://example.org/library/the-republic",
"@type": "Book",
"creator": {"@value": "Plátōn", "@language": "el-Latn"},
"title": {"@value": "Res Publica", "@language": "el-Latn"},
"contains": {
"@id": "http://example.org/library/the-republic#introduction",
"@type": "Chapter",
"description": "An introductory chapter on The Republic.",
"title": "The Introduction"
}
}
}@id
This section is non-normative.
Frames can be matched if they match a specific identifier (@id). This can be illustrated with the original Flattened library objects input using a frame which matches on specific @id values:
{
"@context": {"@vocab": "http://example.org/"},
"@id": "http://example.org/library",
"contains": {
"@id": "http://example.org/library/the-republic",
"contains": {
"@id": "http://example.org/library/the-republic#introduction"
}
}
}
This generates the following framed results:
Example 16: Framed library objects with @id matching{
"@context": {
"@vocab": "http://example.org/"
},
"@id": "http://example.org/library",
"@type": "Library",
"location": "Athens",
"contains": {
"@id": "http://example.org/library/the-republic",
"@type": "Book",
"creator": "Plato",
"title": "The Republic",
"contains": {
"@id": "http://example.org/library/the-republic#introduction",
"@type": "Chapter",
"description": "An introductory chapter on The Republic.",
"title": "The Introduction"
}
}
}Frames can also be matched from an array of identifiers. Within a frame, it is acceptable for @id to have an array value, where the individual values are treated as IRIs.
{
"@context": {"@vocab": "http://example.org/"},
"@id": ["http://example.org/home", "http://example.org/library"],
"contains": {
"@id": ["http://example.org/library/the-republic"],
"contains": {
"@id": ["http://example.org/library/the-republic#introduction"]
}
}
}
This generates the following framed results:
Example 18: Framed library objects with @id matching{
"@context": {"@vocab": "http://example.org/"},
"@id": "http://example.org/library",
"@type": "Library",
"location": "Athens",
"contains": {
"@id": "http://example.org/library/the-republic",
"@type": "Book",
"creator": "Plato",
"title": "The Republic",
"contains": {
"@id": "http://example.org/library/the-republic#introduction",
"@type": "Chapter",
"description": "An introductory chapter on The Republic.",
"title": "The Introduction"
}
}
}This section is non-normative.
An empty frame matches any node object, even if those objects are embedded elsewhere, causing them to be serialized at the top level.
{
"@context": {"@vocab": "http://example.org/"}
}
This generates the following framed results:
Example 20: Framed library objects with empty frame{
"@context": {"@vocab": "http://example.org/"},
"@graph": [{
"@id": "http://example.org/library",
"@type": "Library",
"location": "Athens",
"contains": {
"@id": "http://example.org/library/the-republic",
"@type": "Book",
"creator": "Plato",
"title": "The Republic",
"contains": {
"@id": "http://example.org/library/the-republic#introduction",
"@type": "Chapter",
"description": "An introductory chapter on The Republic.",
"title": "The Introduction"
}
}
}, {
"@id": "http://example.org/library/the-republic",
"@type": "Book",
"creator": "Plato",
"title": "The Republic",
"contains": {
"@id": "http://example.org/library/the-republic#introduction",
"@type": "Chapter",
"description": "An introductory chapter on The Republic.",
"title": "The Introduction"
}
}, {
"@id": "http://example.org/library/the-republic#introduction",
"@type": "Chapter",
"description": "An introductory chapter on The Republic.",
"title": "The Introduction"
}]
}This section is non-normative.
A frame may specify properties that don't exist in an input file. If the explicit inclusion flag is false, the framing algorithm will add a property and value to the result. The @default property in a node object or value object, or as a value of @type, provides a default value to use in the resulting output document. If there is no @default value, the property will be output with a null value. (See § 2.3.3 Omit default flag for ways to avoid this).
Note
The value of the property in the frame is not otherwise used in the output document. It's purpose is for frame matching and finding default values. Note the description value for Library in the following example.
Example 21: Sample library frame with @default value{
"@context": {"@vocab": "http://example.org/"},
"@type": "Library",
"description": "A great Library.",
"contains": {
"@type": "Book",
"description": {"@default": "A great book."},
"contains": {
"@type": "Chapter"
}
}
}Example 22: Sample library output with @default value
{
"@context": {"@vocab": "http://example.org/"},
"@id": "http://example.org/library",
"@type": "Library",
"description": null,
"location": "Athens",
"contains": {
"@id": "http://example.org/library/the-republic",
"@type": "Book",
"creator": "Plato",
"description": "A great book.",
"title": "The Republic",
"contains": {
"@id": "http://example.org/library/the-republic#introduction",
"@type": "Chapter",
"description": "An introductory chapter on The Republic.",
"title": "The Introduction"
}
}
}
Default values may also be used for @type, similar to other properties. In this case, a matched node object without an @type will take the value of the default object from the frame. The default object has a value which is a single IRI. If multiple IRIs are specified, only the first will be used as the default type.
The frame matches objects having specific property values, and provides defaults for @type for matched objects.
{
"@context": {"@vocab": "http://example.org/"},
"@type": "Library",
"contains": {
"@type": {"@default": "Book"},
"creator": "Plato",
"contains": {
"@type": {"@default": "Chapter"},
"description": "An introductory chapter on The Republic."
}
}
}
Data missing specific values for @type, but which matches based on other property values.
{
"@context": {
"@vocab": "http://example.org/",
"contains": {"@type": "@id"}
},
"@graph": [{
"@id": "http://example.org/library",
"@type": "Library",
"contains": "http://example.org/library/the-republic"
}, {
"@id": "http://example.org/library/the-republic",
"creator": "Plato",
"title": "The Republic",
"contains": "http://example.org/library/the-republic#introduction"
}, {
"@id": "http://example.org/library/the-republic#introduction",
"description": "An introductory chapter on The Republic.",
"title": "The Introduction"
}]
}{
"@context": {"@vocab": "http://example.org/"},
"@graph": [{
"@id": "http://example.org/library",
"@type": "Library",
"contains": {
"@id": "http://example.org/library/the-republic",
"@type": "Book",
"contains": {
"@id": "http://example.org/library/the-republic#introduction",
"@type": "Chapter",
"description": "An introductory chapter on The Republic.",
"title": "The Introduction"
},
"creator": "Plato",
"description": "A great book.",
"title": "The Republic"
}
}]
} 2.3 Framing Flags
This section is non-normative.
Framing can be controlled using API options, or by adding framing keywords within the frame as described in § 1.5 Syntax Tokens and Keywords.
Note
Framing flags set using keywords have effect only for the frame in which they appear, and for implicit frames which are created for objects where no frame object exists.
2.3.1 Object Embed FlagThis section is non-normative.
The object embed flag determines if a referenced node object is embedded as a property value of a referencing object, or kept as a node reference. The initial value for the object embed flag is set using the embed@once value of the object embed flag:
{
"@context": {"@vocab": "http://example.org/"},
"@type": "Library"
}{
"@context": {"@vocab": "http://example.org/"},
"@id": "http://example.org/library",
"@type": "Library",
"location": "Athens",
"contains": {
"@id": "http://example.org/library/the-republic",
"@type": "Book",
"creator": "Plato",
"title": "The Republic",
"contains": {
"@id": "http://example.org/library/the-republic#introduction",
"@type": "Chapter",
"description": "An introductory chapter on The Republic.",
"title": "The Introduction"
}
}
}
Because, the default for the object embed flag is @once (in addition to the explicit inclusion flag being false), non-listed properties are added to the output, and implicitly embedded using a default empty frame. As a result, the same output used in the Framed library objects above is generated, assuming that the orderedtrue.
However, if the @embed property is added explicitly with a value of @never, the values for Book and Chapter will be excluded.
{
"@context": {"@vocab": "http://example.org/"},
"@type": "Library",
"contains": {
"@type": "Book",
"@embed": "@never"
}
}Example 29: Framed library objects with @embed set to @never
{
"@context": {"@vocab": "http://example.org/"},
"@id": "http://example.org/library",
"@type": "Library",
"location": "Athens",
"contains": {
"@id": "http://example.org/library/the-republic"
}
}
To illustrate the case where @once does not expand values, consider an alternate library example where books are doubly indexed.
{
"@context": {
"@vocab": "http://example.org/",
"books": {"@type": "@id"},
"contains": {"@type": "@id"}
},
"@graph": [{
"@id": "http://example.org/library",
"@type": "Library",
"books": "http://example.org/library/the-republic",
"contains": "http://example.org/library/the-republic"
}, {
"@id": "http://example.org/library/the-republic",
"@type": "Book",
"creator": "Plato",
"title": "The Republic",
"contains": "http://example.org/library/the-republic#introduction"
}, {
"@id": "http://example.org/library/the-republic#introduction",
"@type": "Chapter",
"description": "An introductory chapter on The Republic.",
"title": "The Introduction"
}]
}{
"@context": {"@vocab": "http://example.org/"},
"@id": "http://example.org/library",
"@type": "Library",
"contains": {"@id": "http://example.org/library/the-republic"},
"books": {
"@id": "http://example.org/library/the-republic",
"@type": "Book",
"creator": "Plato",
"title": "The Republic",
"contains": {
"@id": "http://example.org/library/the-republic#introduction",
"@type": "Chapter",
"description": "An introductory chapter on The Republic.",
"title": "The Introduction"
}
}
}
When framed using the same frame with the default @embed of @once, only the "books" property will have content, if the orderedtrue, and the "contains" property will use a reference.
If we use a frame using "@embed": "@always", both properties will include expanded values.
{
"@context": {"@vocab": "http://example.org/"},
"@type": "Library",
"@embed": "@always"
}Example 33: Framed library objects with double index and @always
{
"@context": {"@vocab": "http://example.org/"},
"@id": "http://example.org/library",
"@type": "Library",
"books": {
"@id": "http://example.org/library/the-republic",
"@type": "Book",
"creator": "Plato",
"title": "The Republic",
"contains": {
"@id": "http://example.org/library/the-republic#introduction",
"@type": "Chapter",
"description": "An introductory chapter on The Republic.",
"title": "The Introduction"
}
},
"contains": {
"@id": "http://example.org/library/the-republic",
"@type": "Book",
"creator": "Plato",
"title": "The Republic",
"contains": {
"@id": "http://example.org/library/the-republic#introduction",
"@type": "Chapter",
"description": "An introductory chapter on The Republic.",
"title": "The Introduction"
}
}
} 2.3.2 Explicit inclusion flag
This section is non-normative.
The explicit inclusion flag used to determine properties which will be included in the output document. The default value is false, which means that properties present in an input node object that are not in the associated frame will be included in the output object. If true, only properties present in the input frame will be placed into the output. The initial value for the explicit inclusion flag is set using the explicit
For example, take an expanded version of the library frame which include some properties from the input, but omit others.
Example 34: Sample library frame with @explicit set to true{
"@context": {"@vocab": "http://example.org/"},
"@type": "Library",
"description": {},
"contains": {
"@type": "Book",
"@explicit": true,
"title": {},
"contains": {
"@type": "Chapter"
}
}
}
The resulting output will exclude properties for Book which are not explicitly listed in the frame object:
Example 35: Framed library objects with @explicit set to true{
"@context": {"@vocab": "http://example.org/"},
"@id": "http://example.org/library",
"@type": "Library",
"description": null ,
"location": "Athens",
"contains": {
"@id": "http://example.org/library/the-republic",
"@type": "Book",
"title": "The Republic",
"contains": {
"@id": "http://example.org/library/the-republic#introduction",
"@type": "Chapter",
"description": "An introductory chapter on The Republic.",
"title": "The Introduction"
}
}
}
Note that the Library object contains a null description property, as it is explicitly called for in the frame using "description": {}. The creator property does not exist in the output, because it is not explicit.
This section is non-normative.
The omit default flag changes the way framing generates output when a property described in the frame is not present in the input document. The initial value for the omit default flag is set using the omitDefault
Consider the following input document:
{
"@context": {
"@vocab": "http://example.org/",
"child": {"@type": "@id"}
},
"@graph": [{
"@id": "http://example.org#John",
"@type": "Person",
"name": "John",
"child": "http://example.org#Jane"
}, {
"@id": "http://example.org#Jane",
"@type": "Person",
"name": "Jane"
}]
}
To illustrate where the omit default flag is useful, consider the following frame, which does not use @omitDefault:
{
"@context": {
"@vocab": "http://example.org/",
"child": {"@type": "@id"}
},
"@type": "Person",
"child": {
"@embed": "@always"
}
}
The resulting output will include a "child" property with the value null, which may not always be desired:
{
"@context": {
"@vocab": "http://example.org/",
"child": {"@type": "@id"}
},
"@graph": [{
"@id": "http://example.org#John",
"@type": "Person",
"name": "John",
"child": {
"@id": "http://example.org#Jane",
"@type": "Person",
"name": "Jane"
}
}, {
"@id": "http://example.org#Jane",
"@type": "Person",
"name": "Jane",
"child": null
}]
}
Note that because the option "@embed": "@always" is specified in the frame under the child property, that "child": null appears in the output for matches that do not have that property, which may be undesirable. To prevent this default null output from occurring, the @omitDefault may be set to true like so:
{
"@context": {
"@vocab": "http://example.org/",
"child": {"@type": "@id"}
},
"@type": "Person",
"child": {
"@embed": "@always",
"@omitDefault": true
}
}
Which yields this (desirable) output:
Example 40: Sample parent/child relationship output with @omitDefault{
"@context": {
"@vocab": "http://example.org/",
"child": {"@type": "@id"}
},
"@graph": [{
"@id": "http://example.org#John",
"@type": "Person",
"name": "John",
"child": {
"@id": "http://example.org#Jane",
"@type": "Person",
"name": "Jane"
}
}, {
"@id": "http://example.org#Jane",
"@type": "Person",
"name": "Jane"
}]
} 2.3.4 Omit graph flag
This section is non-normative.
The omit graph flag determines if framed output containing a single node object is contained within @graph, or not. The initial value for the omit graph flag is set using the omitGraphjson-ld-1.0, the output always includes a @graph entry, otherwise, the @graph entry is used only to describe multiple node objects, consistent with compaction. See § 4.1 Framing Algorithm for a further discussion.
The result is the same as the original Flattened library objects example, but a @graph at the top-level. Example 5 shows the results with the omit graph flag set to true, which is the default value when the processing mode is set to the default json-ld-1.1. The top-level object can be enclosed within @graph by setting the processing mode to json-ld-1.0, or by setting the omit graph flag to false.
{
"@context": {"@vocab": "http://example.org/"},
"@graph": [{
"@id": "http://example.org/library",
"@type": "Library",
"location": "Athens",
"contains": {
"@id": "http://example.org/library/the-republic",
"@type": "Book",
"creator": "Plato",
"title": "The Republic",
"contains": {
"@id": "http://example.org/library/the-republic#introduction",
"@type": "Chapter",
"description": "An introductory chapter on The Republic.",
"title": "The Introduction"
}
}
}]
}This section is non-normative.
The require all flag is used in frame matching to determine when a node object from an input document matches a frame. When matching, an object may include @type and other properties, a match is made when any property value in the object matches the node pattern in the frame object if the value of the require all flag is false (the default). If the flag value is true, then all properties in the frame object must be present in the node object for the node to match.
The following frame matches on multiple properties, including the absence of a property. Using the Flattened library objects example, we can match on an object containing both the title and description or title and creator properties. If we were to use @requireAll set to false, then we could match on the presence of any property, not all properties.
{
"@context": {"@vocab": "http://example.org/"},
"@type": "Library",
"contains": {
"@requireAll": true,
"creator": {},
"title": {},
"contains": {
"@requireAll": true,
"description": {},
"title": {}
}
}
}
This will, again, reproduce the desired framed output:
Example 43: Framed library objects with @requireAll set to true{
"@context": {"@vocab": "http://example.org/"},
"@id": "http://example.org/library",
"@type": "Library",
"location": "Athens",
"contains": {
"@id": "http://example.org/library/the-republic",
"@type": "Book",
"creator": "Plato",
"title": "The Republic",
"contains": {
"@id": "http://example.org/library/the-republic#introduction",
"@type": "Chapter",
"description": "An introductory chapter on The Republic.",
"title": "The Introduction"
}
}
} 2.4 Reverse Framing
This section is non-normative.
A frame may include @reverse, or a value of a term defined using @reverse to invert the relationships in the output object. For example, the Library example can be inverted using the following frame:
{
"@context": {
"@vocab": "http://example.org/",
"within": {"@reverse": "contains"}
},
"@type": "Chapter",
"within": {
"@type": "Book",
"within": {
"@type": "Library"
}
}
}
Using the flattened library example above, results in the following:
{
"@context": {
"@vocab": "http://example.org/",
"within": {"@reverse": "contains"}
},
"@id": "http://example.org/library/the-republic#introduction",
"@type": "Chapter",
"description": "An introductory chapter on The Republic.",
"title": "The Introduction",
"within": {
"@id": "http://example.org/library/the-republic",
"@type": "Book",
"contains": {"@id": "http://example.org/library/the-republic#introduction"},
"creator": "Plato",
"title": "The Republic",
"within": {
"@id": "http://example.org/library",
"@type": "Library",
"location": "Athens",
"contains": {"@id": "http://example.org/library/the-republic"}
}
}
}Note
There is an asymmetry between regular properties and reverse properties. Normally, when framing a node object, unless the explicit inclusion flag is set, all properties of the node are included in the output, but reverse properties are not, as they are not actually properties of the node.
To include reverse properties in the output, add them explicitly to the frame. Note that if the reverse relationship does not exist, it will simply be left out of the output.
2.5 Framing Named GraphsThis section is non-normative.
Frames can include @graph, which allows information from named graphs contained within a JSON-LD document to be exposed within it's proper graph context. By default, framing uses a merged graph, composed of all the node objects across all graphs within the input. By using @graph within a frame, the output document can include information specifically from named graphs contained within the input document.
The following example uses a variation on our library theme where information is split between the default graph, and a graph named http://example.org/graphs/books:
{
"@context": {"@vocab": "http://example.org/"},
"@type": "Library",
"contains": {
"@id": "http://example.org/graphs/books",
"@graph": {
"@type": "Book"
}
}
}
[{
"@context": {"@vocab": "http://example.org/"},
"@id": "http://example.org/graphs/books",
"@graph": [{
"@id": "http://example.org/library/the-republic",
"@type": "http://example.org/Book",
"http://example.org/contains": {
"@id": "http://example.org/library/the-republic#introduction"
},
"http://example.org/creator": "Plato",
"http://example.org/title": "The Republic"
}, {
"@id": "http://example.org/library/the-republic#introduction",
"@type": "http://example.org/Chapter",
"http://example.org/description": "An introductory chapter on The Republic.",
"http://example.org/title": "The Introduction"
}]
}, {
"@context": {"@vocab": "http://example.org/"},
"@id": "http://example.org/library",
"@type": "http://example.org/Library",
"http://example.org/contains": {"@id": "http://example.org/graphs/books"},
"http://example.org/name": "Library"
}]{
"@context": {"@vocab": "http://example.org/"},
"@id": "http://example.org/library",
"@type": "Library",
"name": "Library",
"contains": {
"@id": "http://example.org/graphs/books",
"@graph": {
"@id": "http://example.org/library/the-republic",
"@type": "Book",
"creator": "Plato",
"title": "The Republic",
"contains": {
"@id": "http://example.org/library/the-republic#introduction",
"@type": "Chapter",
"description": "An introductory chapter on The Republic.",
"title": "The Introduction"
}
}
}
} 3. Conformance
As well as sections marked as non-normative, all authoring guidelines, diagrams, examples, and notes in this specification are non-normative. Everything else in this specification is normative.
The key words MAY, MUST, MUST NOT, SHOULD, and SHOULD NOT in this document are to be interpreted as described in BCP 14 [RFC2119] [RFC8174] when, and only when, they appear in all capitals, as shown here.
There is one class of products that can claim conformance to this specification: JSON-LD Processors.
A conforming JSON-LD Processor is a system which can perform the Framing operation in a manner consistent with the algorithms defined in this specification.
JSON-LD Processors MUST NOT attempt to correct malformed IRIs or language tags; however, they MAY issue validation warnings. IRIs are not modified other than conversion between relative and absolute IRIs.
Unless specified using processingMode API option, the processing mode is set using the @version entry in a local context and affects the behavior of algorithms including expansion and compaction. Once set, it is an error to attempt to change to a different processing mode, and processors MUST generate, a processing mode conflict error and abort further processing.
The algorithms in this specification are generally written with more concern for clarity than efficiency. Thus, JSON-LD Processors MAY implement the algorithms given in this specification in any way desired, so long as the end result is indistinguishable from the result that would be obtained by the specification's algorithms.
In algorithm steps that describe operations on keywords, those steps also apply to keyword aliases.
Note
Implementers can partially check their level of conformance to this specification by successfully passing the test cases of the JSON-LD framing test suite. Note, however, that passing all the tests in the test suite does not imply complete conformance to this specification. It only implies that the implementation conforms to aspects tested by the test suite.
4. FramingThe following sections describe algorithms for framing JSON-LD documents. Framing is the process of taking a JSON-LD document, which expresses a graph of information, and applying a specific graph layout (called a Frame).
Framing makes use of the Node Map Generation algorithm to place each object defined in the JSON-LD document into a map of flattened subjects, allowing them to be operated upon by the Framing algorithm.
All algorithms described in this section are intended to operate on language-native data structures. That is, the serialization to a text-based JSON document isn't required as input or output to any of these algorithms.
Reference to JSON data structures are interpreted using their internal representation for the purpose of describing algorithms.
4.1 Framing Algorithm 4.1.1 OverviewA valid JSON-LD Frame is a superset of a valid JSON-LD document, allowing additional content, which is preserved through expansion. The Grammar defined in the JSON-LD 1.1 Syntax specification [JSON-LD11] is extended as follows:
@default MAY include the value @null, or an array containing only @null, in addition to other values allowed in the grammar for values of entry keys expanding to IRIs. Processors MUST preserve this value when expanding. All other entries of a default object MUST be ignored.@id and @type may also be an empty map, an IRI reference, array containing only an empty map, or an array of IRI references. Values of @type MAY also be a map with a @default entry, whose values are restricted by be IRIs. Processors MUST preserve this value when expanding.@graph entry at the top level. Nodes with a subject that is also a named graph, where the frame object contains @graph, extend framing to node objects from the associated named graph.The framing algorithm takes five required input variables and one optional input variable. The required inputs are a framing state (state), a list of subjects to frame, an input frame (expanded frame), a parent used to collect partial frame results, and an active property. The optional input variable is the ordered
The algorithm adds elements to parent either by appending the element to parent, if it is an array, or by appending it to an array associated with active property in parent, if it is a map. Note that if parent is an array, active property MUST be null, and if it is a map, it MUST NOT be null.
invalid frame error has been detected and processing is aborted.
@id entry, its value MUST be either an array containing a single empty map as a value, a valid IRI or an array where all values are valid IRIs.@type entry, its value MUST be either an array containing a single empty map as a value, an array containing a map with a entry whose key is @default, a valid IRI or an array where all values are valid IRIs.@embed, @explicit, and @requireAll in frame.orderedtrue:
@id and id.false and there is an existing embedded node in parent associated with graph name and id in state, do not perform additional processing for this node.true and either embed is @never or if a circular reference would be created by an embed, add output to parent and do not perform additional processing for this node.true, embed is @once, and there is an existing embedded node in parent associated with graph name and id in state, add output to parent and do not perform additional processing for this node.@graph entry, set recurse to true, unless graph name in state is @merged and set subframe to a new empty map.@graph in frame, or a new empty map, if it does not exist, and set recurse to true, unless id is @merged or @default.true:
false.false, the keys from the graph map in state associated with id as subjects, subframe as frame, output as parent, and @graph as active property.@included entry, invoke the algorithm using a copy of state with the value of embedded flag set to false, subjects, frame, output as parent, and @included as active property.orderedtrue:
true, processors MUST NOT add any values for property to output, and the following steps are skipped.@list, then each listitem in the list is processed in sequence and added to a new list map in output:
true, the value of @id from listitem as the sole item in a new subjects array, the first value from @list in frame as frame, list as parent, and @list as active property. If frame does not exist, create a new frame using a new map with properties for @embed, @explicit and @requireAll taken from embed, explicit and requireAll.@list in list.true, the value of @id from item as the sole item in a new subjects array, the first value from property in frame as frame, output as parent, and property as active property. If frame does not exist, create a new frame using a new map with properties for @embed, @explicit and @requireAll taken from embed, explicit and requireAll.@omitDefault with a value of true, or does not contain @omitDefault and the value of the omit default flag in state is true.@preserve and a value that is a copy of the value of @default in frame if it exists, or the string @null otherwise.@reverse, then for each reverse property and sub frame that are the values of @reverse in frame:
@reverse property in output with a new map reverse dict as its value.@id of id:
true, the reverse id as the sole item in a new subjects array, sub frame as frame, null as active property, and the array value of reverse property in reverse dict as parent.The Frame Matching Algorithm is used as part of the Framing algorithm to determine if a particular node object matches the criteria set in a frame. In general, a node object matches a frame if it meets the matches on @type, @id, or if it matches given one of several different properties. If the require all flag is true, all properties must have defaults or match for the frame to match.
Note
As matching is performed on expanded node objects, all values will be in the form of an array.
Node matching uses a combination of JSON constructs to match any, zero, or some specific values:
[] (match none)
[frame object] (node pattern)
[IRI+]
@type and @id, which allows a match on any of the listed IRIs.
[value object] (value pattern)
@value, @type, and @language may also be an array of one or more string values, values of @language are compared without regard to case..
{} (wildcard)
The frame matching algorithm takes the framing state (state), a list of subjects to match from the map of flattened subjects (subjects), a frame to match against (frame), and the requireAll flag and returns a list of matched subjects by filtering each node in subjects as follows:
All properties, including @id and @type, but no other keywords are considered when matching a frame.
@id:
@id property in frame includes any IRI in values.@type property in frame is wildcardmatch noneNote
Framing works on
map of flattened subjects, and the act of flattening ensures that all subjects have an
@id
property; thus the
"@id": []
pattern would never match any
node object. The
"@id": [{}]
pattern would match any
node objectand is equivalent to not specifying a
@id
property in
frameat all
@type:
@type property in frame includes any IRI in values.@type property in frame is wildcard@type property in frame is match none@type property in frame is a default object.@id or @type and does not match, node does not match, and processing is terminated.@default entry with any value, and any other property in node has a non-default match.match nonewildcardvalue pattern (value pattern): property matching is determined using the Value matching algorithm.The Value Pattern Matching Algorithm is used as part of the Framing and Frame Matching algorithms. A value object matches a value pattern using the match nonewildcard@value, @type, and @language, in addition to allowing a specific value to match a set of values defined using the array form for each value object property.
The algorithm takes a value pattern (pattern) and value object (value) as parameters. Value matches pattern using the following algorithm:
@value, @type, and @language in value, or null if none exists, where values of @language are normalized to lower case..@value, @type, and @language in value pattern, or null if none exists, where string values of @language are normalized to lower case..wildcardwildcardwildcardnull and t2 is null or match nonewildcardnull and l2 is null or match noneThis API provides a clean mechanism that enables developers to convert JSON-LD data into a variety of output formats that are easier to work with in various programming languages. If a JSON-LD API is provided in a programming environment, the entirety of the following API MUST be implemented.
The JSON-LD API uses Promises to represent the result of the various deferred operations. Promises are defined in [ECMASCRIPT]. General use within specifications can be found in [promises-guide]. Implementations MAY chose to implement in an appropriate way for their native environments as long as they generally use the same methods, arguments, and options and return the same results.
Note
Interfaces are marked [Exposed=JsonLd], which creates a global interface. The use of WebIDL in JSON-LD, while appropriate for use within browsers, is not limited to such use.
The JSON-LD Processor interface is the high-level programming structure that developers use to access the JSON-LD transformation methods. The definition below is an experimental extension of the interface defined in the JSON-LD 1.1 API [JSON-LD11-API].
It is important to highlight that implementations do not modify the input parameters. If an error is detected, the Promise is rejected with a JsonLdFramingError having an appropriate code
[Global=JsonLd, Exposed=JsonLd] interfaceJsonLd{}; [Exposed=JsonLd] interfaceJsonLdProcessor{constructor(); static Promise<JsonLdRecord>frame(JsonLdInputinput,JsonLdInputframe, optionalJsonLdOptionsoptions = {}); };
The JsonLdProcessor interface frame() method Frames the given input using frame according to the steps in the Framing Algorithm:
Promise promise and return it. The following steps are then executed asynchronously.orderedfalse.true, and theorderedfalse.@context from remote frame or frame, if it exists, or to a new empty context, otherwise.documentUrl from remote frame, if available, otherwise to the base option from options.null.@graph set the frameDefaulttrue.embed@once.falseexplicitfalse.requireAllfalse.omitDefaultfalse.@default if frameDefaulttrue, otherwise to false.@merged, add en entry for @merged in graph map set to the result of the Merge Node Maps algorithm passing graph map.null as active property.json-ld-1.0, remove the @id entry of each node object in results where the entry value is a blank node identifier which appears only once in any property value within results.@preserve with the first value of that entry.
Note
The value of the entry will be an array with a single value; this will effectively replace the map containing @preserve with that value.
compact method using active context, inverse context, null for active property, results as element,, and the compactArrays and ordered@graph and value is compacted results.@context entry to compacted results and set its value to the provided context.@null values in compacted results with null. If, after replacement, an array contains only the value null remove that value, leaving an empty array.omitGraphfalse and compacted results does not have a top-level @graph entry, or its value is not an array, modify compacted results to place the non @context entry of compacted results into a map contained within the array value of @graph. If omitGraphtrue, a top-level @graph entry is used only to contain multiple node objects.input; either in the form of an map or as IRI.
JsonLdOptionstypedef record<USVString, any> JsonLdRecord;
The JsonLdRecord is the definition of a map used to contain arbitrary map entries which are the result of parsing a JSON Object.
typedef (JsonLdRecordor sequence<JsonLdRecord> or USVString or RemoteDocument)JsonLdInput;
The JsonLdInput interface is used to refer to an input value that that may be a JsonLdRecord, a sequence of JsonLdRecords, a string representing an IRI, which can be dereferenced to retrieve a valid JSON document, or an already dereferenced RemoteDocument.
When the value is a JsonLdRecord or sequence of JsonLdRecords, the values are taken as their equivalent internal representation values, where a JsonLdRecord is equivalent to a map, and a sequence of JsonLdRecords is equivalent to an array of maps. The map entries are converted to their equivalents in [INFRA].
The JsonLdFramingError type is used to report processing errors.
dictionaryJsonLdFramingError{JsonLdFramingErrorCodecode; USVString?message= null; }; enumJsonLdFramingErrorCode{ "invalid frame", "invalid @embed value" };
JSON-LD Framing extends the error interface and codes defined in JSON-LD 1.1 Processing Algorithms and API the JSON-LD 1.1 API [JSON-LD11-API].
code
message
The JsonLdFramingErrorCode represents the collection of valid JSON-LD Framing error codes.
invalid @embed value
@embed is not one recognized for the object embed flag.
invalid frame
This section describes datatype definitions used within the JSON-LD API.
5.3.1 JsonLdContextThe JsonLdContext type is used to refer to a value that that may be a map, a string representing an IRI, or an array of maps and strings.
See JsonLdContext definition in the JSON-LD 1.1 API [JSON-LD11-API].
5.3.2 JsonLdOptionsThe JsonLdOptions type is used to pass various options to the JsonLdProcessor methods.
dictionaryJsonLdOptions{ (JsonLdEmbedor boolean)embed= "@once"; booleanexplicit= false; booleanomitDefault= false; booleanomitGraph; booleanrequireAll= false; booleanframeDefault= false; booleanordered= false; }; enumJsonLdEmbed{ "@always", "@once", "@never" };
In addition to those options defined in the JSON-LD 1.1 API [JSON-LD11-API], framing defines these additional options:
embed
true sets the flag to @once, while a value of false sets the flag to @never.
explicit
frameDefault
omitDefault
omitGraph
false if processing mode is json-ld-1.0, true otherwise.
ordered
true, certain algorithm processing steps where indicated are ordered lexicographically. If false, order is not considered in processing.
requireAll
JsonLdEmbed enumerates the values of the embed
@always
@never
@once
@embed nor object embed flag is specified.
See JsonLdOptions definition in the JSON-LD 1.1 API [JSON-LD11-API].
6. Security ConsiderationsSee, Security Considerations in § A. IANA Considerations.
7. Privacy ConsiderationsSee, Privacy Considerations in [JSON-LD11].
8. Internationalization ConsiderationsSee, Internationalization Considerations in [JSON-LD11].
A. IANA ConsiderationsThis section is included merely for standards community review and will be submitted to the Internet Engineering Steering Group if this specification becomes a W3C Recommendation.
A JSON-LD Frame uses the same MIME media type described in [JSON-LD11] along with a required profile parameter.
profile
A single URI identifying the resource as a JSON-LD Frame. A profile does not change the semantics of the resource representation when processed without profile knowledge, so that clients both with and without knowledge of a profiled resource can safely use the same representation.
http://www.w3.org/ns/json-ld#framed
The http://www.w3.org/ns/json-ld#framed SHOULD be used when serving and requesting a JSON-LD frame document.
Since JSON-LD is intended to be a pure data exchange format for directed graphs, the serialization SHOULD NOT be passed through a code execution mechanism such as JavaScript's eval() function to be parsed. An (invalid) document may contain code that, when executed, could lead to unexpected side effects compromising the security of a system.
When processing JSON-LD documents, links to remote contexts are typically followed automatically, resulting in the transfer of files without the explicit request of the user for each one. If remote contexts are served by third parties, it may allow them to gather usage patterns or similar information leading to privacy concerns. Specific implementations, such as the API defined in the JSON-LD 1.1 Processing Algorithms and API specification [JSON-LD11-API], may provide fine-grained mechanisms to control this behavior.
JSON-LD contexts that are loaded from the Web over non-secure connections, such as HTTP, run the risk of being altered by an attacker such that they may modify the JSON-LD active context in a way that could compromise security. It is advised that any application that depends on a remote context for mission critical purposes vet and cache the remote context before allowing the system to use it.
Given that JSON-LD allows the substitution of long IRIs with short terms, JSON-LD documents may expand considerably when processed and, in the worst case, the resulting data might consume all of the recipient's resources. Applications should treat any data with due skepticism.
As JSON-LD places no limits on the IRI schemes that may be used, and vocabulary-relative IRIs use string concatenation rather than IRI resolution, it is possible to construct IRIs that may be used maliciously, if dereferenced.
Fragment identifiers used with application/ld+json are treated as in RDF syntaxes, as per RDF 1.1 Concepts and Abstract Syntax [RDF11-CONCEPTS].
B. IDL IndexThis section is non-normative.
[Global=JsonLd, Exposed=C. Open IssuesJsonLd] interfaceJsonLd{}; [Exposed=JsonLd] interfaceJsonLdProcessor{constructor(); static Promise<JsonLdRecord>frame(JsonLdInputinput,JsonLdInputframe, optionalJsonLdOptionsoptions = {}); }; typedef record<USVString, any>JsonLdRecord; typedef (JsonLdRecordor sequence<JsonLdRecord> or USVString or RemoteDocument)JsonLdInput; dictionaryJsonLdFramingError{JsonLdFramingErrorCodecode; USVString?message= null; }; enumJsonLdFramingErrorCode{ "invalid frame", "invalid @embed value" }; dictionaryJsonLdOptions{ (JsonLdEmbedor boolean)embed= "@once"; booleanexplicit= false; booleanomitDefault= false; booleanomitGraph; booleanrequireAll= false; booleanframeDefault= false; booleanordered= false; }; enumJsonLdEmbed{ "@always", "@once", "@never" };
This section is non-normative.
The following is a list of issues open at the time of publication.
Allow class-scoped framing.
Several frames in the same frame document?
D. Changes since 1.0 Draft of 30 August 2012This section is non-normative.
@embed) can take on different values to better control object embedding.wildcardmatch none@value, @type, and @language can use wildcardmatch none@reverse.@id to allow for matching specific objects in a frame.json-ld-1.0, @id entries with blank node identifiers used only for that @id are removed.@link and in-memory object linking.omitDefaultorderedfalse This is used in algorithms to control iteration of map entry keys. Previously, the algorithms always required such an order. The instructions for evaluating test results have been updated accordingly.@reverse, or a term defined with @reverse, which can cause nodes referencing a node targeted by a frame to have a reverse reference created.This section is non-normative.
orderedfalse This is used in algorithms to control iteration of map entry keys. Previously, the algorithms always required such an order. The instructions for evaluating test results have been updated accordingly.application/ld-frame+json to application/ld+json with a required profile parameter.@id and @type.@first and @last values for the object embed flag in favor of @once.json-ld-1.1, unless set explicitly to json-ld-1.0.@type can have a default value, which is not used for frame matching purposes.This section is non-normative.
JsonLdProcessorThis section is non-normative.
[Exposed=(Window,Worker)] to [Exposed=JsonLd], which is declared as a global interface in order to expose the JsonLdProcessorThis section is non-normative.
The editors would like to specially thank the following individuals for making significant contributions to the authoring and editing of this specification:
Additionally, the following people were members of the Working Group at the time of publication:
A large amount of thanks goes out to the JSON-LD Community Group participants who worked through many of the technical issues on the mailing list and the weekly telecons: Chris Webber, David Wood, Drummond Reed, Eleanor Joslin, Fabien Gandon, Herm Fisher, Jamie Pitts, Kim Hamilton Duffy, Niklas Lindström, Paolo Ciccarese, Paul Frazze, Paul Warren, Reto Gmür, Rob Trainer, Ted Thibodeau Jr., and Victor Charpenay.
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