json_tokener.h File Reference

Data Structures

struct  json_tokener_srec
struct  json_tokener

Defines

#define JSON_TOKENER_MAX_DEPTH   32

Enumerations

enum  json_tokener_error {
  json_tokener_success, json_tokener_continue, json_tokener_error_depth, json_tokener_error_parse_eof,
  json_tokener_error_parse_unexpected, json_tokener_error_parse_null, json_tokener_error_parse_boolean, json_tokener_error_parse_number,
  json_tokener_error_parse_array, json_tokener_error_parse_object_key_name, json_tokener_error_parse_object_key_sep, json_tokener_error_parse_object_value_sep,
  json_tokener_error_parse_string, json_tokener_error_parse_comment
}
enum  json_tokener_state {
  json_tokener_state_eatws, json_tokener_state_start, json_tokener_state_finish, json_tokener_state_null,
  json_tokener_state_comment_start, json_tokener_state_comment, json_tokener_state_comment_eol, json_tokener_state_comment_end,
  json_tokener_state_string, json_tokener_state_string_escape, json_tokener_state_escape_unicode, json_tokener_state_boolean,
  json_tokener_state_number, json_tokener_state_array, json_tokener_state_array_add, json_tokener_state_array_sep,
  json_tokener_state_object_field_start, json_tokener_state_object_field, json_tokener_state_object_field_end, json_tokener_state_object_value,
  json_tokener_state_object_value_add, json_tokener_state_object_sep
}

Functions

const char * json_tokener_error_desc (enum json_tokener_error jerr)
enum json_tokener_error json_tokener_get_error (struct json_tokener *tok)
struct json_tokenerjson_tokener_new (void)
void json_tokener_free (struct json_tokener *tok)
void json_tokener_reset (struct json_tokener *tok)
struct json_objectjson_tokener_parse (const char *str)
struct json_objectjson_tokener_parse_verbose (const char *str, enum json_tokener_error *error)
struct json_objectjson_tokener_parse_ex (struct json_tokener *tok, const char *str, int len)

Variables

const char * json_tokener_errors []

Define Documentation

#define JSON_TOKENER_MAX_DEPTH   32

Enumeration Type Documentation

Enumerator:
json_tokener_success 
json_tokener_continue 
json_tokener_error_depth 
json_tokener_error_parse_eof 
json_tokener_error_parse_unexpected 
json_tokener_error_parse_null 
json_tokener_error_parse_boolean 
json_tokener_error_parse_number 
json_tokener_error_parse_array 
json_tokener_error_parse_object_key_name 
json_tokener_error_parse_object_key_sep 
json_tokener_error_parse_object_value_sep 
json_tokener_error_parse_string 
json_tokener_error_parse_comment 
Enumerator:
json_tokener_state_eatws 
json_tokener_state_start 
json_tokener_state_finish 
json_tokener_state_null 
json_tokener_state_comment_start 
json_tokener_state_comment 
json_tokener_state_comment_eol 
json_tokener_state_comment_end 
json_tokener_state_string 
json_tokener_state_string_escape 
json_tokener_state_escape_unicode 
json_tokener_state_boolean 
json_tokener_state_number 
json_tokener_state_array 
json_tokener_state_array_add 
json_tokener_state_array_sep 
json_tokener_state_object_field_start 
json_tokener_state_object_field 
json_tokener_state_object_field_end 
json_tokener_state_object_value 
json_tokener_state_object_value_add 
json_tokener_state_object_sep 

Function Documentation

const char* json_tokener_error_desc ( enum json_tokener_error  jerr  ) 

Given an error previously returned by json_tokener_get_error(), return a human readable description of the error.

Returns:
a generic error message is returned if an invalid error value is provided.
void json_tokener_free ( struct json_tokener tok  ) 
enum json_tokener_error json_tokener_get_error ( struct json_tokener tok  ) 

Retrieve the error caused by the last call to json_tokener_parse_ex(), or json_tokener_success if there is no error.

When parsing a JSON string in pieces, if the tokener is in the middle of parsing this will return json_tokener_continue.

See also json_tokener_error_desc().

struct json_tokener* json_tokener_new ( void   )  [read]
struct json_object* json_tokener_parse ( const char *  str  )  [read]
struct json_object* json_tokener_parse_ex ( struct json_tokener tok,
const char *  str,
int  len 
) [read]

Parse a string and return a non-NULL json_object if a valid JSON value is found. The string does not need to be a JSON object or array; it can also be a string, number or boolean value.

A partial JSON string can be parsed. If the parsing is incomplete, NULL will be returned and json_tokener_get_error() will be return json_tokener_continue. json_tokener_parse_ex() can then be called with additional bytes in str to continue the parsing.

If json_tokener_parse_ex() returns NULL and the error anything other than json_tokener_continue, a fatal error has occurred and parsing must be halted. Then tok object must not be re-used until json_tokener_reset() is called.

When a valid JSON value is parsed, a non-NULL json_object will be returned. Also, json_tokener_get_error() will return json_tokener_success. Be sure to check the type with json_object_is_type() or json_object_get_type() before using the object.

XXX this shouldn't use internal fields: Trailing characters after the parsed value do not automatically cause an error. It is up to the caller to decide whether to treat this as an error or to handle the additional characters, perhaps by parsing another json value starting from that point.

Extra characters can be detected by comparing the tok->char_offset against the length of the last len parameter passed in.

The tokener does not maintain an internal buffer so the caller is responsible for calling json_tokener_parse_ex with an appropriate str parameter starting with the extra characters.

Example:

json_object *jobj = NULL;
const char *mystring = NULL;
int stringlen = 0;
enum json_tokener_error jerr;
do {
        mystring = ...  // get JSON string, e.g. read from file, etc...
        stringlen = strlen(mystring);
        jobj = json_tokener_parse_ex(tok, mystring, stringlen);
} while ((jerr = json_tokener_get_error(tok)) == json_tokener_continue);
if (jerr != json_tokener_success)
{
        fprintf(stderr, "Error: %s\n", json_tokener_error_desc(jerr));
        // Handle errors, as appropriate for your application.
}
if (tok->char_offset < stringlen) // XXX shouldn't access internal fields
{
        // Handle extra characters after parsed object as desired.
        // e.g. issue an error, parse another object from that point, etc...
}
// Success, use jobj here.
Parameters:
tok a json_tokener previously allocated with json_tokener_new()
str an string with any valid JSON expression, or portion of. This does not need to be null terminated.
len the length of str
struct json_object* json_tokener_parse_verbose ( const char *  str,
enum json_tokener_error error 
) [read]
void json_tokener_reset ( struct json_tokener tok  ) 

Variable Documentation

const char* json_tokener_errors[]

XXX do not use json_tokener_errors directly. After v0.10 this will be removed.

See json_tokener_error_desc() instead.

Generated on Sat Apr 28 15:52:47 2012 for json-c by  doxygen 1.6.3