Frame

A static analysis pass that maps URIs and pointers to subschemas. More...

Classes
class	sourcemeta::blaze::SchemaFrame
class	sourcemeta::blaze::SchemaFrameError
class	sourcemeta::blaze::SchemaAnchorCollisionError

Enumerations
enum class	sourcemeta::blaze::SchemaFrame::LocationType : std::uint8_t { Resource , Anchor , Pointer , Subschema }

Detailed Description

A static analysis pass that maps URIs and pointers to subschemas.

This functionality is included as follows:

#include <sourcemeta/blaze/frame.h>

---

Class Documentation

sourcemeta::blaze::SchemaFrame

class sourcemeta::blaze::SchemaFrame

This class performs a static analysis pass on the input schema, computing things such as the static identifiers and references of a schema.

For example:

#include <sourcemeta/core/json.h>
#include <sourcemeta/blaze/foundation.h>
#include <cassert>
 
const sourcemeta::core::JSON document =
    sourcemeta::core::parse_json(R"JSON({
  "$id": "https://www.example.com/schema",
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "items": { "$id": "foo", "type": "string" },
  "properties": {
    "foo": { "$anchor": "test", "type": "number" },
    "bar": { "$ref": "#/properties/foo" }
  }
})JSON");
 
sourcemeta::blaze::SchemaFrame
  frame{sourcemeta::blaze::SchemaFrame::Mode::References};
 
frame.analyse(document,
  sourcemeta::blaze::schema_walker,
  sourcemeta::blaze::schema_resolver);

Public Types
enum class	Mode : std::uint8_t { Locations , References }
enum class	LocationType : std::uint8_t { Resource , Anchor , Pointer , Subschema }
using	References = std::map< std::pair< SchemaReferenceType, sourcemeta::core::WeakPointer >, ReferencesEntry >
using	Locations = std::map< std::pair< SchemaReferenceType, sourcemeta::core::JSON::String >, Location >
using	Paths = std::vector< sourcemeta::core::WeakPointer >
	A list of paths to frame within a schema wrapper.
Public Member Functions
	SchemaFrame (const Mode mode)
	SchemaFrame (const SchemaFrame &)=delete
auto	operator= (const SchemaFrame &) -> SchemaFrame &=delete
	SchemaFrame (SchemaFrame &&)=delete
auto	operator= (SchemaFrame &&) -> SchemaFrame &=delete
auto	mode () const noexcept -> Mode
auto	to_json (const std::optional< sourcemeta::core::PointerPositionTracker > &tracker=std::nullopt) const -> sourcemeta::core::JSON
	Export the frame entries as JSON.
auto	analyse (const sourcemeta::core::JSON &root, const SchemaWalker &walker, const SchemaResolver &resolver, std::string_view default_dialect="", std::string_view default_id="", const Paths &paths={sourcemeta::core::empty_weak_pointer}) -> void
auto	locations () const noexcept -> const Locations &
	Access the analysed schema locations.
auto	references () const noexcept -> const References &
	Access the analysed schema references.
auto	reference (const SchemaReferenceType type, const sourcemeta::core::WeakPointer &pointer) const -> std::optional< std::reference_wrapper< const ReferencesEntry > >
	Get a specific reference entry by type and pointer.
auto	standalone () const noexcept -> bool
	Check whether the analysed schema has no external references.
auto	root () const noexcept -> const sourcemeta::core::JSON::String &
	Get the root schema identifier (empty if none)
auto	vocabularies (const Location &location, const SchemaResolver &resolver) const -> Vocabularies
	Get the vocabularies associated with a location entry.
auto	uri (const Location &location, const sourcemeta::core::WeakPointer &relative_schema_location=sourcemeta::core::empty_weak_pointer) const -> sourcemeta::core::JSON::String
	Get the URI associated with a location entry.
auto	traverse (const Location &location, const sourcemeta::core::WeakPointer &relative_schema_location) const -> const Location &
	Get the location associated by traversing a pointer from another location.
auto	traverse (const std::string_view uri) const -> std::optional< std::reference_wrapper< const Location > >
	Get the location associated with a given URI.
auto	traverse (const sourcemeta::core::WeakPointer &pointer) const -> std::optional< std::reference_wrapper< const Location > >
	Get the location associated with a given pointer.
auto	traverse (const sourcemeta::core::WeakPointer &pointer, const LocationType type) const -> std::optional< std::reference_wrapper< const Location > >
	Get the location of a specific type associated with a given pointer.
auto	uri (const sourcemeta::core::WeakPointer &pointer) const -> std::optional< std::reference_wrapper< const sourcemeta::core::JSON::String > >
	Turn an absolute pointer into a location URI.
auto	dereference (const Location &location, const sourcemeta::core::WeakPointer &relative_schema_location=sourcemeta::core::empty_weak_pointer) const -> std::pair< SchemaReferenceType, std::optional< std::reference_wrapper< const Location > > >
	Try to dereference a reference location into its destination location.
template<std::invocable< std::string_view > F>
auto	for_each_resource_uri (const F &callback) const -> void
	Iterate over all resource URIs in the frame.
template<std::invocable< const sourcemeta::core::WeakPointer &, const ReferencesEntry & > F>
auto	for_each_unresolved_reference (const F &callback) const -> void
auto	has_references_to (const sourcemeta::core::WeakPointer &pointer) const -> bool
	Check if there are any references to a given location pointer.
auto	has_references_through (const sourcemeta::core::WeakPointer &pointer) const -> bool
	Check if there are any references that go through a given location pointer.
auto	has_references_through (const sourcemeta::core::WeakPointer &pointer, const sourcemeta::core::WeakPointer::Token &tail) const -> bool
auto	relative_instance_location (const Location &location) const -> sourcemeta::core::WeakPointer
	Get the relative instance location pointer for a given location entry.
auto	empty () const noexcept -> bool
	Check if the frame has no analysed data.
auto	reset () -> void
	Reset the frame, clearing all analysed data.
auto	is_reachable (const Location &base, const Location &location, const SchemaWalker &walker, const SchemaResolver &resolver) const -> bool
	Determines if a location could be evaluated during validation.

Member Typedef Documentation

Locations

using sourcemeta::blaze::SchemaFrame::Locations = std::map<std::pair<SchemaReferenceType, sourcemeta::core::JSON::String>, Location>

A JSON Schema reference frame is a mapping of URIs to schema identifiers, JSON Pointers within the schema, and subschemas dialects. We call it reference frame as this mapping is essential for resolving references.

References

using sourcemeta::blaze::SchemaFrame::References = std::map<std::pair<SchemaReferenceType, sourcemeta::core::WeakPointer>, ReferencesEntry>

A JSON Schema reference map is a mapping of a JSON Pointer of a subschema to a destination static reference URI. For convenience, the value consists of the URI on its entirety, but also broken down by its potential fragment component. The reference type is part of the key as it is possible to have a static and a dynamic reference to the same location on the same schema object.

Member Enumeration Documentation

Mode

enum class sourcemeta::blaze::SchemaFrame::Mode : std::uint8_t

strong

The mode of framing. More extensive analysis can be compute and memory intensive

Member Function Documentation

analyse()

auto sourcemeta::blaze::SchemaFrame::analyse	(	const sourcemeta::core::JSON &	root,
		const SchemaWalker &	walker,
		const SchemaResolver &	resolver,
		std::string_view	default_dialect = "",
		std::string_view	default_id = "",
		const Paths &	paths = {sourcemeta::core::empty_weak_pointer}
	)		-> void

Analyse a schema or set of schemas from a given root. Passing multiple paths that have any overlap is undefined behaviour

for_each_unresolved_reference()

template<std::invocable< const sourcemeta::core::WeakPointer &, const ReferencesEntry & > F>

auto sourcemeta::blaze::SchemaFrame::for_each_unresolved_reference ( const F &  callback ) const -> void

inline

Iterate over all unresolved references (where destination cannot be traversed)

has_references_through()

auto sourcemeta::blaze::SchemaFrame::has_references_through	(	const sourcemeta::core::WeakPointer &	pointer,
		const sourcemeta::core::WeakPointer::Token &	tail
	)		const -> bool

Check if there are any references that go through a given location pointer with a tail token

sourcemeta::blaze::SchemaFrameError

class sourcemeta::blaze::SchemaFrameError

An error that represents a schema frame error

Inheritance diagram for sourcemeta::blaze::SchemaFrameError:

Public Member Functions
	SchemaFrameError (const std::string_view identifier, const char *message)
auto	what () const noexcept -> const char *override
auto	identifier () const noexcept -> std::string_view

sourcemeta::blaze::SchemaAnchorCollisionError

class sourcemeta::blaze::SchemaAnchorCollisionError

An error that represents a schema anchor collision error

Inheritance diagram for sourcemeta::blaze::SchemaAnchorCollisionError:

Public Member Functions
	SchemaAnchorCollisionError (const std::string_view identifier, sourcemeta::core::Pointer location, sourcemeta::core::Pointer other)
auto	what () const noexcept -> const char *override
auto	identifier () const noexcept -> std::string_view
auto	location () const noexcept -> const sourcemeta::core::Pointer &
auto	other () const noexcept -> const sourcemeta::core::Pointer &

Enumeration Type Documentation

LocationType

enum class sourcemeta::blaze::SchemaFrame::LocationType : std::uint8_t

strong

The type of a location frame