Files | |
file | qoferror.h |
Extensible error handling. | |
Defines | |
#define | QOF_MOD_ERROR "qof-error-module" |
#define | QOF_SUCCESS 0 |
#define | QOF_FATAL -1 |
general error value | |
Typedefs | |
typedef struct QofError_s | QofError |
Functions | |
QofErrorId | qof_error_register (const gchar *err_message, gboolean use_file) |
Generate and register a new error. | |
void | qof_error_unregister (QofErrorId id) |
Unregister an error. | |
void | qof_error_set (QofSession *session, QofErrorId error) |
Add an error to the stack for this session. | |
void | qof_error_set_be (QofBackend *be, QofErrorId error) |
void | qof_error_clear (QofSession *session) |
clear the error stack for the session. | |
QofErrorId | qof_error_check_be (QofBackend *be) |
Check for errors. | |
QofErrorId | qof_error_check (QofSession *session) |
QofTime * | qof_error_get_time_be (QofBackend *be) |
Get the time of the most recent error. | |
QofTime * | qof_error_get_time (QofSession *session) |
Alternative for applications. | |
QofErrorId | qof_error_get_id_be (QofBackend *be) |
Pop the most recent error from the backend stack. | |
QofErrorId | qof_error_get_id (QofSession *session) |
Alternative for applications. | |
const gchar * | qof_error_get_message_be (QofBackend *be) |
Pop the most recent error and get the message. | |
const gchar * | qof_error_get_message (QofSession *session) |
Alternative for applications. |
An error must be registered to be set. Registered errors can be set repeatedly into an error stack for the relevant session. Setting an error copies the registered error to the error stack and sets a time index in the copy.
Once an error has been unregistered, it cannot be set later. If the error has already been set on the error stack, the stack is not changed and the error remains readable.
Each error stack is specific to one QofSession.
Registered errors can be set in any session (if the QofErrorId is known) but most errors are specific to one session.
Applications can register new error values with qof_error_register passing the error message string, already marked for translation - a new QofErrorId will be returned. Error values are unregistered when the session ends or can be unregistered manually.
Each backend can also generate specific QofError values, in which case the translation is done within QOF.
Set an error by passing the QofErrorId (or the deprecated QofBackendError) to qof_error_set.
To check the error condition use qof_error_check - if an error has been set, qof_error_check returns the QofErrorId of that error without clearing the error from the stack.
To retrieve an error and clear it from the stack, use qof_error_get_id or qof_error_get_message.
Precise values of QofErrorId are not to be stored in applications as values (other than deprecated values) may change at any time.
There are no default errors - previous QofBackendError values are retained only as deprecated macros. Until libqof2, QofErrorId is guaranteed not to overlap a previous QofBackendError value but once deprecated code is removed in libqof2, any value can be used.
This deliberately makes it harder to re-use the same error time after time. The purpose is to encourage more detailed error reporting by supporting an unlimited number of error values.
Applications and backends can store the QofErrorId in a context or static values if the error must be set from multiple locations, otherwise an error can be registered and set locally.
If a subsystem or dependency generates an error message of it's own, this can also be passed to qof_error_register to generate a new error within the session, complete with the (translated) message direct from the subsystem. This increases the detail and clarity of the messages presented to the user. Programming errors and complex errors should still be logged using QofLog - QofError is for messages destined for the end user of the application using QOF.
Many applications already include message strings for the previous QofBackendError values but all are welcome to move to the new QofError strings.
QofError strings remain the property of QofError and should not be freed.
#define QOF_FATAL -1 |
general error value
Can be returned by any function handling QofErrorId to indicate a fatal error, e.g. g_return_val_if_fail
Definition at line 131 of file qoferror.h.
#define QOF_MOD_ERROR "qof-error-module" |
QofError log_module name.
Definition at line 121 of file qoferror.h.
#define QOF_SUCCESS 0 |
success value
Definition at line 124 of file qoferror.h.
typedef struct QofError_s QofError |
opaque QofError type.
Definition at line 118 of file qoferror.h.
QofErrorId qof_error_check | ( | QofSession * | session | ) |
alternative for applications.
Definition at line 197 of file qoferror.c.
00198 { 00199 g_return_val_if_fail (session, QOF_FATAL); 00200 return qof_error_check_be (session->backend); 00201 }
QofErrorId qof_error_check_be | ( | QofBackend * | be | ) |
Check for errors.
be | The backend to check. |
Definition at line 204 of file qoferror.c.
00205 { 00206 QofError * qerr; 00207 GList * first; 00208 00209 if (!be) 00210 return QOF_FATAL; 00211 if (g_list_length (be->error_stack) == 0) 00212 return QOF_SUCCESS; 00213 first = g_list_first (be->error_stack); 00214 qerr = (QofError*)first->data; 00215 if (!qerr) 00216 return QOF_FATAL; 00217 return qerr->id; 00218 }
void qof_error_clear | ( | QofSession * | session | ) |
clear the error stack for the session.
Applications should clear the stack once errors have been presented to the user.
Definition at line 182 of file qoferror.c.
00183 { 00184 g_return_if_fail (session); 00185 if (!session->backend) 00186 return; 00187 g_list_foreach (session->backend->error_stack, clear_list, NULL); 00188 g_list_free (session->backend->error_stack); 00189 session->backend->error_stack = NULL; 00190 if (session->error_message) 00191 g_free (session->error_message); 00192 session->error_message = NULL; 00193 session->last_err = QOF_SUCCESS; 00194 }
QofErrorId qof_error_get_id_be | ( | QofBackend * | be | ) |
Pop the most recent error from the backend stack.
Returns and clears the most recently set error for this backend, if any.
be | The Backend that recorded the error. |
Definition at line 266 of file qoferror.c.
00267 { 00268 QofError * qerr; 00269 GList * first; 00270 00271 if (!be) 00272 return QOF_FATAL; 00273 if (g_list_length (be->error_stack) == 0) 00274 return QOF_SUCCESS; 00275 first = g_list_first (be->error_stack); 00276 qerr = (QofError*)first->data; 00277 if (!qerr) 00278 return QOF_FATAL; 00279 be->error_stack = 00280 g_list_remove (be->error_stack, qerr); 00281 return qerr->id; 00282 }
const gchar* qof_error_get_message_be | ( | QofBackend * | be | ) |
Pop the most recent error and get the message.
Clears the most recently set error for this backend and returns the error message, if any.
be | The Backend that recorded the error. |
Definition at line 298 of file qoferror.c.
00299 { 00300 QofError * qerr; 00301 GList * first; 00302 00303 g_return_val_if_fail (be, NULL); 00304 if (g_list_length (be->error_stack) == 0) 00305 { 00306 DEBUG (" empty error stack"); 00307 return NULL; 00308 } 00309 first = g_list_first (be->error_stack); 00310 qerr = (QofError*)first->data; 00311 if (!qerr) 00312 { 00313 DEBUG (" empty QofError value"); 00314 return NULL; 00315 } 00316 DEBUG (" qerr->message=%s", qerr->message); 00317 be->error_stack = 00318 g_list_remove (be->error_stack, qerr); 00319 return qerr->message; 00320 }
QofTime* qof_error_get_time_be | ( | QofBackend * | be | ) |
Get the time of the most recent error.
All QofError values are timestamped at the moment that the error is set.
be | The Backend where the error was set. |
Definition at line 221 of file qoferror.c.
00222 { 00223 QofError * qerr; 00224 GList * first; 00225 00226 if (g_list_length(be->error_stack) == 0) 00227 return NULL; 00228 first = g_list_first (be->error_stack); 00229 qerr = (QofError*)first->data; 00230 return qerr->qt; 00231 }
QofErrorId qof_error_register | ( | const gchar * | err_message, | |
gboolean | use_file | |||
) |
Generate and register a new error.
err_message | The user-friendly string to add as an error, already marked for translation. | |
use_file | TRUE if the session filename should be substituted in the string - err_message must contain a bare string format specifier: s. Note that flags, width, precision or size specifiers are not accepted and the filename is output in full, complete with the access_method. e.g. file:/home/user/app/data.xml |
Registered errors are cleared when the session is destroyed.
Applications need to plan the use of locally registered error codes so that the same errors are not repeatedly registered.
Definition at line 73 of file qoferror.c.
00074 { 00075 QofError * qerr; 00076 00077 ENTER (" "); 00078 qerr = g_new0 (QofError, 1); 00079 count++; 00080 qerr->id = count; 00081 if (use_file) 00082 { 00083 gchar * spec; 00084 00085 spec = g_strrstr (err_message, "%s"); 00086 use_file = (spec) ? TRUE : FALSE; 00087 } 00088 qerr->use_file = use_file; 00089 qerr->message = g_strdup (err_message); 00090 g_hash_table_insert (error_table, GINT_TO_POINTER(qerr->id), qerr); 00091 LEAVE (" "); 00092 return qerr->id; 00093 }
void qof_error_set | ( | QofSession * | session, | |
QofErrorId | error | |||
) |
Add an error to the stack for this session.
session | The session that raised the error. | |
error | The QofErrorId of the error to be recorded. |
Definition at line 112 of file qoferror.c.
00113 { 00114 QofError * qerr, * set; 00115 00116 g_return_if_fail (session); 00117 if (error == QOF_SUCCESS) 00118 { 00119 DEBUG (" passed success, not error."); 00120 return; 00121 } 00122 qerr = g_hash_table_lookup (error_table, GINT_TO_POINTER(error)); 00123 if (!qerr) 00124 { 00125 DEBUG (" failed hash table lookup"); 00126 return; 00127 } 00128 session->last_err = error; 00129 if (session->error_message) 00130 g_free (session->error_message); 00131 if (qerr->use_file) 00132 session->error_message = g_strdup_printf (qerr->message, 00133 qof_session_get_url (session)); 00134 else 00135 session->error_message = g_strdup (qerr->message); 00136 if (!session->backend) 00137 return; 00138 /* create a new error for the list */ 00139 set = g_new0 (QofError, 1); 00140 if (qerr->use_file) 00141 set->message = g_strdup_printf (qerr->message, 00142 qof_session_get_file_path (session)); 00143 else 00144 set->message = g_strdup (qerr->message); 00145 set->id = error; 00146 set->qt = qof_time_get_current (); 00147 session->backend->error_stack = 00148 g_list_prepend (session->backend->error_stack, set); 00149 }
void qof_error_unregister | ( | QofErrorId | id | ) |
Unregister an error.
Registered errors are normally freed when the session ends. Errors can also be unregistered (and freed) directly.
An unregistered error can not be set later.
Definition at line 96 of file qoferror.c.
00097 { 00098 QofError * qerr; 00099 gboolean result; 00100 00101 ENTER (" "); 00102 qerr = g_hash_table_lookup (error_table, GINT_TO_POINTER(id)); 00103 qof_error_free (qerr); 00104 result = g_hash_table_remove (error_table, 00105 GINT_TO_POINTER(id)); 00106 if (!result) 00107 LEAVE ("unable to remove registered error."); 00108 LEAVE (" ok."); 00109 }