.. type:: json_error_t
- This opaque structure is used to return information on errors from
- the decoding functions. See below for more discussion on error
- reporting.
+ This data structure is used to return information on decoding
+ errors from the decoding functions. Its definition is repeated
+ here::
-The following functions perform the JSON decoding:
+ #define JSON_ERROR_TEXT_LENGTH 160
-.. function:: json_t *json_loads(const char *input, size_t flags, json_error_t **error)
+ typedef struct {
+ char text[JSON_ERROR_TEXT_LENGTH];
+ int line;
+ } json_error_t;
- .. refcounting:: new
-
- Decodes the JSON string *input* and returns the array or object it
- contains, or *NULL* on error. If *error* is non-*NULL*, it's used
- to return error information. See below for more discussion on error
- reporting. *flags* is currently unused, and should be set to 0.
-
-.. function:: json_t *json_loadf(FILE *input, size_t flags, json_error_t **error)
+ *line* is the line number on which the error occurred, or -1 if
+ this information is not available. *text* contains the error
+ message (in UTF-8), or an empty string if a message is not
+ available.
- .. refcounting:: new
+ The normal usef of :type:`json_error_t` is to allocate it normally
+ on the stack, and pass a pointer to a decoding function. Example::
- Decodes the JSON text in stream *input* and returns the array or
- object it contains, or *NULL* on error. If *error* is non-*NULL*,
- it's used to return error information. See below for more
- discussion on error reporting. *flags* is currently unused, and
- should be set to 0.
+ int main() {
+ json_t *json;
+ json_error_t error;
-.. function:: json_t *json_load_file(const char *path, size_t flags, json_error_t **error)
+ json = json_load_file("/path/to/file.json", 0, &error);
+ if(!json) {
+ /* the error variable contains error information */
+ }
+ ...
+ }
- .. refcounting:: new
+ Also note that if the decoding succeeded (``json != NULL`` in the
+ above example), the contents of ``error`` are unspecified.
- Decodes the JSON text in file *path* and returns the array or
- object it contains, or *NULL* on error. If *error* is non-*NULL*,
- it's used to return error information. See below for more
- discussion on error reporting. *flags* is currently unused, and
- should be set to 0.
-
-
-The :type:`json_error_t` parameter, that all decoding function accept
-as their last parameter, is used to return information on decoding
-errors to the caller. It is used by having a ``json_error_t *``
-variable and passing a pointer to this variable to a decoding
-function. Example::
-
- int main() {
- json_t *json;
- json_error_t *error;
-
- json = json_load_file("/path/to/file.json", 0, &error);
- if(!json) {
- /* the error variable contains error information */
- fprintf(stderr, "Decoding error occured on line %d: %s\n", json_error_line(error), json_error_msg(error));
- free(error);
- }
-
- /* ... */
- }
+ All decoding functions also accept *NULL* as the
+ :type:`json_error_t` pointer, in which case no error information
+ is returned to the caller.
-Note that **the caller must free the error structure** after use if a
-decoding error occurs. If decoding is succesfully finished, *error* is
-simply set to *NULL* by the decoding function.
+The following functions perform the actual JSON decoding.
-All decoding functions also accept *NULL* as the :type:`json_error_t`
-pointer, in which case no error information is returned to the caller.
-Example::
+.. function:: json_t *json_loads(const char *input, size_t flags, json_error_t *error)
- int main() {
- json_t *json;
+ .. refcounting:: new
- json = json_load_file("/path/to/file.json", 0, NULL);
- if(!json) {
- /* A decoding error occured but no error information is available */
- }
+ Decodes the JSON string *input* and returns the array or object it
+ contains, or *NULL* on error, in which case *error* is filled with
+ information about the error. See above for discussion on the
+ *error* parameter. *flags* is currently unused, and should be set
+ to 0.
- /* ... */
- }
+.. function:: json_t *json_loadf(FILE *input, size_t flags, json_error_t *error)
-:type:`json_error_t` is totally opaque and must be queried using the
-following functions:
+ .. refcounting:: new
-.. function:: const char *json_error_msg(const json_error_t *error)
+ Decodes the JSON text in stream *input* and returns the array or
+ object it contains, or *NULL* on error, in which case *error* is
+ filled with information about the error. See above for discussion
+ on the *error* parameter. *flags* is currently unused, and should
+ be set to 0.
- Return a pointer to an UTF-8 encoded string that describes the
- error in human-readable text, or *NULL* if *error* is *NULL*.
+.. function:: json_t *json_load_file(const char *path, size_t flags, json_error_t *error)
-.. function:: int json_error_line(const json_error_t *error)
+ .. refcounting:: new
- Return the line numer on which the error occurred, or -1 if this
- information is not available or if *error* is *NULL*.
+ Decodes the JSON text in file *path* and returns the array or
+ object it contains, or *NULL* on error, in which case *error* is
+ filled with information about the error. See above for discussion
+ on the *error* parameter. *flags* is currently unused, and should
+ be set to 0.
Equality
projects / jansson.git / blobdiff