Fix slot-inheritance during JSON type-registration

Previously, only direct-slots were registered; now
those of parent classes are also registered to
*JSON-TYPES*.
This commit is contained in:
Jaidyn Ann 2024-08-21 17:44:58 -05:00
parent 6fab9f42d3
commit bae4fbbd13

View File

@ -19,7 +19,11 @@
(:use #:cl)
(:nicknames "AS/JSON-LD" "JSON-LD")
(:export
#:define-json-type #:json-ld-context))
#:define-json-type
;; Accessors
#:json-ld-context #:json-ld-etc #:json-ld-id #:json-ld-type
;; Slots
:@context :@id :@type :.etc))
(in-package #:activity-servist/json-ld)
@ -33,7 +37,7 @@
;;; Base class
;;; ————————————————————————————————————————
(defclass json-ld-type ()
(defclass json-ld-object ()
((@context
:initform nil
:documentation
@ -41,28 +45,57 @@
The method JSON-LD-CONTEXT is how the contents of encoded @context is
determined; to change a classes default/calculated @context, override that
method. This slot is for changing a specific objects @context.")
(etc
(@id
:initform nil
:accessor json-ld-id
:documentation
"Provides the globally unique identifier for an object.")
(@type
:initform nil
:accessor json-ld-type
:documentation
"Identifies the type of an object. Used to determine the corresponding CLOS-object.")
(.etc
:initform nil
:accessor json-ld-etc
:documentation
"Components of the JSON object which, during parsing, did not match any specific
slot. This is often filled up in the case of undefined node-types or non-adherent
object definitions.")))
(setf (gethash "*" *json-types*)
'((json-ld-object)
("@context" @context . "@context")
("@id" @id . "@id")
("@type" @type . "@type")))
(defgeneric json-ld-context (obj)
(:documentation
"Returns a JSON-LD CLOS objects @context, for use in JSON-encoding of the
object.
The implementation for the JSON-LD-TYPE class simply returns the activitystreams
The implementation for the JSON-LD-OBJECT class simply returns the activitystreams
URL.
If you would like to change @context on a class-level, override this method.
If you would like to change it on an object-level, set the @CONTEXT slot."))
(defmethod json-ld-context ((obj json-ld-type))
(defmethod json-ld-context ((obj json-ld-object))
(or (slot-value obj '@context)
"https://www.w3.org/ns/activitystreams"))
(defmethod yason:encode-slots progn ((obj json-ld-type))
(defmethod yason:encode-slots progn ((obj json-ld-object))
(let ((context (json-ld-context obj))
(id (json-ld-id obj))
(type (json-ld-type obj)))
(when context
(yason:encode-object-element "@context" (json-ld-context obj)))
(when id
(yason:encode-object-element "@id" (json-ld-id obj)))
(when type
(yason:encode-object-element "@type" (json-ld-type obj))))
(mapcar (lambda (alist-cell)
(yason:encode-object-element (car alist-cell)
(cdr alist-cell)))
(json-ld-etc obj)))
@ -78,8 +111,9 @@ encoding as @types value. If only the CLOS class-name is provided, @type will
not be encoded for this object.
DIRECT-SUPERCLASSES is a list of JSON-LD CLOS classes, whose slots and context
this should inherit. JSON-LD-TYPE should be somewhere in the hierarchy, in order
to provide @context; if no superclasses are provided, JSON-LD-TYPE is default.
this should inherit. JSON-LD-OBJECT should be somewhere in the hierarchy, in order
to provide @context, @id, and @type; if no superclasses are provided,
JSON-LD-OBJECT is default.
CONTEXT is a context hash-table, parsed from a JSON-LD context by JSON-LD:PARSE
or JSON-LD:PARSE-CONTEXT. Any terms defined in this context will be used to
@ -94,13 +128,7 @@ encoded nor decoded in JSON.
SLOT-OPTIONS are key/value pairs in the format of DEFCLASSes slot-options.
Keywords such as :INITFORM, :DOCUMENTATION, etc. can be used.
There are two keywords with behavior unlike DEFCLASS, however:
:REQUIRED and :ACCESSOR.
By default, a slot will have an init-form of NIL; this can of course be
overridden by putting :INITFORM yourself in the slot definition.
Set :REQUIRED to T to not set :INITFORM at all, effectively making the slot
required.
There is one keyword with behavior unlike DEFCLASS, however :ACCESSOR.
By default, a slot will have an accessor named after the class and slot, like
PLACE-RADIUS for the class PLACE and the slot RADIUS.
@ -115,17 +143,15 @@ Here is a brief example partially defining the “Place” type from ActivityStr
((altitude altitude
:documentation Indicates the altitude of a place.)
(latitude latitude
:required T
:documentation The latitude of a place.)
(longitude longitude
:required T
:documentation The longitude of a place.)))"
`(let ((json-class
(define-json-clos-class ,names
,(or direct-superclasses `(json-ld-type))
,(or direct-superclasses `(json-ld-object))
,direct-slots ,options)))
(define-json-type-encoder ,(car names) ,direct-slots)
(register-json-type ',names ',direct-slots ,context)
(register-json-type ',names (or ',direct-superclasses '(json-ld-object)) ',direct-slots ,context)
json-class))
(defmacro define-json-clos-class (names direct-superclasses direct-slots options)
@ -153,21 +179,15 @@ applying default slot-options, etc."
(defun json-type-implicit-slot-options (class-name slot-name)
"Return default property-list slot options for a json-type CLOS class."
(list :initform nil
:accessor (intern (format nil "~A-~A" class-name slot-name))))
(list :accessor (intern (format nil "~A-~A" class-name slot-name))))
(defun json-type-normalize-slot-options (slot-opts)
"Take property-list slot options from a DEFINE-JSON-TYPE format and massage it
into a DEFCLASS format."
(let* ((required (getf slot-opts :required))
(sans-required (alexandria:remove-from-plist slot-opts :required))
(sans-initform-maybe (if required
(alexandria:remove-from-plist sans-required :initform)
sans-required))
(sans-accessor-maybe (if (and (find :accessor slot-opts)
(let* ((sans-accessor-maybe (if (and (find :accessor slot-opts)
(not (getf slot-opts :accessor)))
(alexandria:remove-from-plist sans-initform-maybe :accessor)
sans-initform-maybe)))
(alexandria:remove-from-plist slot-opts :accessor)
slot-opts)))
sans-accessor-maybe))
@ -181,28 +201,32 @@ CLASS is the class-name; see DEFINE-JSON-TYPEs docstring about DIRECT-SLOTS."
(append
`(defmethod yason:encode-slots progn ((obj ,class)))
(mapcar (lambda (slot)
`(yason:encode-object-element ,(cadr slot) (slot-value obj ',(car slot))))
`(when (slot-boundp obj ',(car slot))
(yason:encode-object-element ,(cadr slot) (slot-value obj ',(car slot)))))
direct-slots)))
;;; Parsing
;;; ————————————————————————————————————————
(defun register-json-type (names direct-slots context)
(defun register-json-type (names direct-superclasses direct-slots context)
"Register a JSON node-type. This allows PARSE to recognize the type (and
corresponding CLOS class) of a node."
(let* ((ctx (parse-context context))
(type-iri (getf (gethash (cadr names) ctx) :id))
(type-name (or type-iri (cadr names))))
(setf (gethash type-name *json-types*)
(json-type-registry-list names ctx direct-slots))))
(json-type-registry-list names direct-superclasses ctx direct-slots))))
(defun json-type-registry-list (names parsed-context direct-slots)
(defun json-type-registry-list (names direct-superclasses parsed-context direct-slots)
"Return a REGISTER-JSON-TYPE-formed registry entry, a simple list of the form:
(TYPE-IRI (PROPERTY-NAME SLOT-NAME) (PROPERTY-NAME SLOT-NAME))
where TYPE-IRI is the (hopefully) fully-resolved IRI form of the node-types
name, though it might be unresolved if context was unprovided or lacking."
(append (list (cons (car names) (cadr names)))
(append
;; The class-name and type-name.
(list (cons (car names) (cadr names)))
;; Add the classes direct slots.
(mapcar
(lambda (slot)
(when (cadr slot)
@ -212,7 +236,16 @@ name, though it might be unresolved if context was unprovided or lacking."
(url (or (getf ctx-item :id)
property-name)))
(cons url (cons slot-name property-name)))))
direct-slots)))
direct-slots)
;; Add the slots of parent-classes.
(reduce (lambda (slots-a slots-b)
(append slots-a slots-b))
(mapcar (lambda (class-name)
(let* ((type-name (class-json-type-name class-name))
(type-registry (gethash type-name *json-types*)))
(if type-registry
type-registry)))
direct-superclasses))))
(defun parse (str)
"Parse the JSON-LD document contained in STR."
@ -240,11 +273,10 @@ name, though it might be unresolved if context was unprovided or lacking."
(getf val :id))))
;; Now, actually parse.
(let* ((parsed-table (parse-table-inplace table ctx))
(type (identify-json-type table ctx rev-ctx))
(typedef (gethash type *json-types*)))
(if typedef
(parse-table-into-object parsed-table typedef ctx rev-ctx) ; We prefer this!
parsed-table)))) ; … but just in case you wanna use an undefined type…
(type (identify-json-type table ctx))
(type-def (or (gethash type *json-types*)
(gethash "*" *json-types*))))
(parse-table-into-object parsed-table type-def ctx rev-ctx))))
(defun parse-table-inplace (table ctx)
"Expand a YASON-parsed JSON-LD node-object in TABLE. That is, replace all
@ -279,17 +311,17 @@ CTX is the according parsed-context, and REV-CTX is the reversed
(lambda (property value)
(let* ((property-def (assoc property type-def :test #'equal))
(slot-name (second property-def))
(etc-value (slot-value obj 'etc)))
(etc-value (slot-value obj '.etc)))
(if property-def
(setf (slot-value obj slot-name) value)
(setf (slot-value obj 'etc)
(setf (slot-value obj '.etc)
(append etc-value
(list (cons property value)))))))
table)
(setf (slot-value obj '@context) (gethash "@context" table))
obj))
(defun identify-json-type (table ctx rev-ctx)
(defun identify-json-type (table ctx)
"Given an parsed JSON-LD objects hash-TABLE, return the name/IRI of the
JSON-type that best suits the object using the types registered into
*JSON-TYPES* with REGISTER-JSON-TYPE."
@ -297,6 +329,13 @@ JSON-type that best suits the object — using the types registered into
(or (getf (gethash type ctx) :id)
type)))
(defun class-json-type-name (class-name)
"Return the name (IRI) of a registered JSON-type its CLOS classes name."
(loop for iri being the hash-keys in *json-types*
for registry being the hash-values in *json-types*
if (eq class-name (caar registry))
return iri))
;;; Context-parsing