JSON Writer and Loader

Data Structures
struct	pj_json_list
struct	pj_json_elem
struct	pj_json_err_info

Typedefs
typedef pj_status_t(*	pj_json_writer) (const char *s, unsigned size, void *user_data)

Enumerations
enum	pj_json_val_type {   PJ_JSON_VAL_NULL , PJ_JSON_VAL_BOOL , PJ_JSON_VAL_NUMBER , PJ_JSON_VAL_STRING ,   PJ_JSON_VAL_ARRAY , PJ_JSON_VAL_OBJ }

Functions
void	pj_json_elem_null (pj_json_elem *el, pj_str_t *name)
void	pj_json_elem_bool (pj_json_elem *el, pj_str_t *name, pj_bool_t val)
void	pj_json_elem_number (pj_json_elem *el, pj_str_t *name, float val)
void	pj_json_elem_string (pj_json_elem *el, pj_str_t *name, pj_str_t *val)
void	pj_json_elem_array (pj_json_elem *el, pj_str_t *name)
void	pj_json_elem_obj (pj_json_elem *el, pj_str_t *name)
void	pj_json_elem_add (pj_json_elem *el, pj_json_elem *child)
pj_json_elem *	pj_json_parse (pj_pool_t *pool, char *buffer, unsigned *size, pj_json_err_info *err_info)
pj_status_t	pj_json_write (const pj_json_elem *elem, char *buffer, unsigned *size)
pj_status_t	pj_json_writef (const pj_json_elem *elem, pj_json_writer writer, void *user_data)

Detailed Description

This API implements JSON file format according to RFC 4627. It can be used to parse, write, and manipulate JSON documents.

Typedef Documentation

pj_json_writer

typedef pj_status_t(* pj_json_writer) (const char *s, unsigned size, void *user_data)

Type of function callback to write JSON document in pj_json_writef().

Parameters

s	The string to be written to the document.
size	The length of the string
user_data	User data that was specified to pj_json_writef()

Returns

If the callback returns non-PJ_SUCCESS, it will stop the pj_json_writef() function and this error will be returned to caller.

Enumeration Type Documentation

pj_json_val_type

enum pj_json_val_type

Type of JSON value.

Enumerator
PJ_JSON_VAL_NULL	Null value (null)
PJ_JSON_VAL_BOOL	Boolean value (true, false)
PJ_JSON_VAL_NUMBER	Numeric (float or fixed point)
PJ_JSON_VAL_STRING	Literal string value.
PJ_JSON_VAL_ARRAY	Array
PJ_JSON_VAL_OBJ	Object.

Function Documentation

pj_json_elem_add()

void pj_json_elem_add	(	pj_json_elem *	el,
		pj_json_elem *	child
	)

Add an element to an object or array.

Parameters

el	The object or array element.
child	Element to be added to the object or array.

pj_json_elem_array()

void pj_json_elem_array	(	pj_json_elem *	el,
		pj_str_t *	name
	)

Initialize element as an empty array

Parameters

el	The element.
name	Name to be given to the element, or NULL.

pj_json_elem_bool()

void pj_json_elem_bool	(	pj_json_elem *	el,
		pj_str_t *	name,
		pj_bool_t	val
	)

Initialize boolean element with the specified value.

Parameters

el	The element.
name	Name to be given to the element, or NULL.
val	The value.

pj_json_elem_null()

void pj_json_elem_null	(	pj_json_elem *	el,
		pj_str_t *	name
	)

Initialize null element.

Parameters

el	The element.
name	Name to be given to the element, or NULL.

pj_json_elem_number()

void pj_json_elem_number	(	pj_json_elem *	el,
		pj_str_t *	name,
		float	val
	)

Initialize number element with the specified value.

Parameters

el	The element.
name	Name to be given to the element, or NULL.
val	The value.

pj_json_elem_obj()

void pj_json_elem_obj	(	pj_json_elem *	el,
		pj_str_t *	name
	)

Initialize element as an empty object

Parameters

el	The element.
name	Name to be given to the element, or NULL.

pj_json_elem_string()

void pj_json_elem_string	(	pj_json_elem *	el,
		pj_str_t *	name,
		pj_str_t *	val
	)

Initialize string element with the specified value.

Parameters

el	The element.
name	Name to be given to the element, or NULL.
val	The value.

pj_json_parse()

pj_json_elem * pj_json_parse	(	pj_pool_t *	pool,
		char *	buffer,
		unsigned *	size,
		pj_json_err_info *	err_info
	)

Parse a JSON document in the buffer. The buffer MUST be NULL terminated, or if not then it must have enough size to put the NULL character.

Parameters

pool	The pool to allocate memory for creating elements.
buffer	String buffer containing JSON document.
size	Size of the document.
err_info	Optional structure to be filled with info when parsing failed.

Returns

The root element from the document.

pj_json_write()

pj_status_t pj_json_write	(	const pj_json_elem *	elem,
		char *	buffer,
		unsigned *	size
	)

Write the specified element to the string buffer.

Parameters

elem	The element to be written.
buffer	Output buffer.
size	On input, it must be set to the size of the buffer. Upon successful return, this will be set to the length of the written string.

Returns

PJ_SUCCESS on success or the appropriate error.

pj_json_writef()

pj_status_t pj_json_writef	(	const pj_json_elem *	elem,
		pj_json_writer	writer,
		void *	user_data
	)

Incrementally write the element to arbitrary medium using the specified callback to write the document chunks.

Parameters

elem	The element to be written.
writer	Callback function which will be called to write text chunks.
user_data	Arbitrary user data which will be given back when calling the callback.

Returns

PJ_SUCCESS on success or the appropriate error.

References PJ_END_DECL.