JSONContext Struct Reference

#include <JSONContext.h>

Overview

A context for JSON serialization and deserialization.

Create one instance per operation. Errors encountered during parsing or type-binding accumulate in errors.

Definition at line 72 of file JSONContext.h.

Inheritance diagram for JSONContext:

Properties
Array *	errors
	Errors accumulated during the operation.
Object	object
	The superclass.
Properties inherited from Object
Class *	clazz
	Every instance of Object begins with a pointer to its Class.
unsigned int	magic
	A header to allow introspection of Object types.

Methods
Class *	_JSONContext (void)
	The JSONContext archetype.
Data *	dataFromObject (JSONContext *self, const ident obj, int options)
	Serializes an Objectively object graph to JSON Data.
Data *	dataFromStruct (JSONContext *self, const JSONProperties *properties, const ident instance)
	Serializes a C struct instance to a JSON object.
Data *	dataFromStructs (JSONContext *self, const JSONProperties *properties, const ident instances, size_t count)
	Serializes an array of C struct instances to a JSON array.
Dictionary *	dictionaryFromStruct (JSONContext *self, const JSONProperties *properties, const ident instance)
	Serializes a C struct instance to a Dictionary.
JSONContext *	init (JSONContext *self)
	Initializes a JSONContext.
ident	objectFromData (JSONContext *self, const Data *data, int options)
	Parses a JSON Data buffer into an Objectively object graph.
bool	structFromData (JSONContext *self, const JSONProperties *properties, const Data *data, ident instance)
	Deserializes a top-level JSON object into a C struct.
bool	structFromDictionary (JSONContext *self, const JSONProperties *properties, const Dictionary *dictionary, ident instance)
	Deserializes a Dictionary into a C struct.
size_t	structsFromArray (JSONContext *self, const JSONProperties *properties, const Array *array, ident instances, size_t count)
	Deserializes an Array of Dictionaries into an array of C structs.
size_t	structsFromData (JSONContext *self, const JSONProperties *properties, const Data *data, ident instances, size_t count)
	Deserializes a top-level JSON array into an array of C structs.
Methods inherited from Object
Class *	_Object (void)
	The Object archetype.
Object *	copy (const Object *self)
	Creates a shallow copy of this Object.
void	dealloc (Object *self)
	Frees all resources held by this Object.
String *	description (const Object *self)
int	hash (const Object *self)
Object *	init (Object *self)
	Initializes this Object.
bool	isEqual (const Object *self, const Object *other)
	Tests equality of the other Object.
bool	isKindOfClass (const Object *self, const Class *clazz)
	Tests for Class hierarchy membership.

Protected Attributes
JSONContextInterface *	interface
	The interface.
Protected Attributes inherited from Object
ObjectInterface *	interface
	The interface.

Property Details

errors

Array* JSONContext::errors

Errors accumulated during the operation.

Lazily allocated; NULL until the first error is recorded.

Definition at line 89 of file JSONContext.h.

interface

JSONContextInterface* JSONContext::interface

protected

The interface.

Definition at line 83 of file JSONContext.h.

object

Object JSONContext::object

The superclass.

Definition at line 77 of file JSONContext.h.

Method Details

_JSONContext()

Class * _JSONContext

(

void

)

The JSONContext archetype.

Returns

The JSONContext Class.

Definition at line 821 of file JSONContext.c.

                          {
  static Class *clazz;
  static Once once;
 
  do_once(&once, {
    clazz = _initialize(&(const ClassDef) {
      .name = "JSONContext",
      .superclass = _Object(),
      .instanceSize = sizeof(JSONContext),
      .interfaceOffset = offsetof(JSONContext, interface),
      .interfaceSize = sizeof(JSONContextInterface),
      .initialize = initialize,
      .destroy = destroy,
    });
  });
 
  return clazz;
}

dataFromObject()

Data * dataFromObject	(	JSONContext *	self,
		const ident	obj,
		int	options
	)

Serializes an Objectively object graph to JSON Data.

Parameters

self	The JSONContext.
obj	The root Object to serialize.
options	A bitwise-or of JSONWriteOptions.

Returns

The resulting JSON Data.

Definition at line 584 of file JSONContext.c.

                                                                             {
 
  (void) self;
 
  if (obj) {
    JSONWriter writer = {
      .data = $(alloc(Data), init),
      .options = options
    };
 
    writeElement(&writer, obj);
 
    return (Data *) writer.data;
  }
 
  return NULL;
}

dataFromStruct()

Data * dataFromStruct	(	JSONContext *	self,
		const JSONProperties *	properties,
		const ident	instance
	)

Serializes a C struct instance to a JSON object.

Parameters

self	The JSONContext.
properties	The JSONProperties for the struct type.
instance	Pointer to the struct instance.

Returns

The resulting JSON Data.

Definition at line 606 of file JSONContext.c.

                                                                                                       {
 
  Dictionary *dict = $(self, dictionaryFromStruct, properties, instance);
  Data *data = dataFromObject(self, dict, 0);
  release(dict);
  return data;
}

dataFromStructs()

Data * dataFromStructs	(	JSONContext *	self,
		const JSONProperties *	properties,
		const ident	instances,
		size_t	count
	)

Serializes an array of C struct instances to a JSON array.

Parameters

self	The JSONContext.
properties	The JSONProperties for the struct type.
instances	Pointer to the first instance.
count	The number of instances to serialize.

Returns

The resulting JSON Data (a top-level JSON array), or NULL if count is zero.

Definition at line 618 of file JSONContext.c.

                                                                                                                       {
 
  if (!count) {
    return NULL;
  }
 
  Array *array = $(alloc(Array), init);
 
  for (size_t i = 0; i < count; i++) {
    const ident instance = instances + i * properties->size;
    Dictionary *dict = $(self, dictionaryFromStruct, properties, instance);
    $(array, addObject, dict);
    release(dict);
  }
 
  Data *data = dataFromObject(self, array, 0);
  release(array);
  return data;
}

dictionaryFromStruct()

Dictionary * dictionaryFromStruct	(	JSONContext *	self,
		const JSONProperties *	properties,
		const ident	instance
	)

Serializes a C struct instance to a Dictionary.

Parameters

self	The JSONContext.
properties	The JSONProperties for the struct type.
instance	Pointer to the struct instance.

Returns

A new Dictionary, or NULL on error.

Definition at line 641 of file JSONContext.c.

                                                                                                                   {
 
  if (!properties || !instance) {
    return NULL;
  }
 
  Dictionary *dict = $(alloc(Dictionary), init);
 
  for (const JSONProperty *p = properties->properties; p->key; p++) {
    if (!p->serializer) {
      continue;
    }
 
    const ident field = instance + p->offset;
    ident val = p->serializer(properties, p, field, p->data, self);
 
    if (val) {
      String *key = $$(String, stringWithCharacters, p->key);
      $(dict, setObjectForKey, val, key);
      release(key);
      release(val);
    }
  }
 
  return (Dictionary *) dict;
}

init()

JSONContext * init

(

JSONContext *

self

)

Initializes a JSONContext.

Parameters

self	The JSONContext.

Returns

The initialized JSONContext.

Definition at line 671 of file JSONContext.c.

                                            {
  return (JSONContext *) super(Object, self, init);
}

objectFromData()

ident objectFromData	(	JSONContext *	self,
		const Data *	data,
		int	options
	)

Parses a JSON Data buffer into an Objectively object graph.

Parameters

self	The JSONContext.
data	The JSON Data to parse.
options	Reserved; pass 0.

Returns

The root Object (Dictionary or Array), or NULL on parse error.

Definition at line 679 of file JSONContext.c.

                                                                              {
 
  if (data && data->length) {
    JSONReader reader = {
      .data = data,
      .options = options
    };
 
    ident obj = readElement(&reader);
 
    if (reader.error) {
      addError(self, 1, NULL, "JSON parse error");
      release(obj);
      return NULL;
    }
 
    return obj;
  }
 
  return NULL;
}

structFromData()

bool structFromData	(	JSONContext *	self,
		const JSONProperties *	properties,
		const Data *	data,
		ident	instance
	)

Deserializes a top-level JSON object into a C struct.

Parameters

self	The JSONContext.
properties	The JSONProperties for the struct type.
data	The JSON Data containing a top-level object.
instance	Pointer to the caller-allocated struct to populate.

Returns

true if parsing succeeded and all recognized fields were bound without type errors.

Definition at line 757 of file JSONContext.c.

                                                                                                                  {
 
  ident obj = $(self, objectFromData, data, 0);
  if (!obj || !$((Object *) obj, isKindOfClass, _Dictionary())) {
    release(obj);
    return false;
  }
 
  const bool ok = structFromDictionary(self, properties, (Dictionary *) obj, instance);
 
  release(obj);
  return ok;
}

structFromDictionary()

bool structFromDictionary	(	JSONContext *	self,
		const JSONProperties *	properties,
		const Dictionary *	dictionary,
		ident	instance
	)

Deserializes a Dictionary into a C struct.

Parameters

self	The JSONContext.
properties	The JSONProperties for the struct type.
dictionary	The source Dictionary.
instance	Pointer to the caller-allocated struct to populate.

Returns

true if all recognized fields were bound without type errors.

Definition at line 704 of file JSONContext.c.

                                                                                                                                    {
 
  if (!properties || !dictionary || !instance) {
    return false;
  }
 
  bool ok = true;
 
  for (const JSONProperty *p = properties->properties; p->key; p++) {
    if (!p->deserializer) {
      continue;
    }
 
    String *key = $$(String, stringWithCharacters, p->key);
    const Object *val = $(dictionary, objectForKey, key);
    release(key);
 
    if (!val) {
      continue;
    }
 
    if (!p->deserializer(properties, p, val, instance + p->offset, self)) {
      addError(self, 2, p->key, "type mismatch");
      ok = false;
    }
  }
 
  return ok;
}

structsFromArray()

size_t structsFromArray	(	JSONContext *	self,
		const JSONProperties *	properties,
		const Array *	array,
		ident	instances,
		size_t	count
	)

Deserializes an Array of Dictionaries into an array of C structs.

Parameters

self	The JSONContext.
properties	The JSONProperties for the element type.
array	The source Array of Dictionary objects.
instances	Pointer to a caller-allocated buffer of at least count structs.
count	The capacity of the instances buffer.

Returns

The number of structs actually written.

Definition at line 737 of file JSONContext.c.

                                                                                                                                       {
 
  if (!properties || !array || !instances || !count) {
    return 0;
  }
 
  const size_t n = min(array->count, count);
 
  for (size_t i = 0; i < n; i++) {
    const Dictionary *dictionary = cast(Dictionary, $(array, objectAtIndex, i));
    $(self, structFromDictionary, properties, dictionary, instances + i * properties->size);
  }
 
  return n;
}

structsFromData()

size_t structsFromData	(	JSONContext *	self,
		const JSONProperties *	properties,
		const Data *	data,
		ident	instances,
		size_t	count
	)

Deserializes a top-level JSON array into an array of C structs.

Parameters

self	The JSONContext.
properties	The JSONProperties for the element type.
data	The JSON Data containing a top-level array.
instances	Pointer to a caller-allocated buffer of at least count structs.
count	The capacity of the instances buffer.

Returns

The number of structs actually written.

Definition at line 775 of file JSONContext.c.

                                                                                                                                    {
 
  ident obj = objectFromData(self, data, 0);
  if (!obj || !$((Object *) obj, isKindOfClass, _Array())) {
    release(obj);
    return 0;
  }
 
  const size_t n = structsFromArray(self, properties, (Array *) obj, instances, count);
 
  release(obj);
  return n;
}

---

The documentation for this struct was generated from the following files:

• Sources/Objectively/JSONContext.h
• Sources/Objectively/JSONContext.c