QOF
0.7.5
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Files | |
file | qoferror.h |
Extensible error handling. | |
Macros | |
#define | QOF_MOD_ERROR "qof-error-module" |
#define | QOF_SUCCESS 0 |
#define | QOF_FATAL -1 |
general error value More... | |
Typedefs | |
typedef struct QofError_s | QofError |
Functions | |
QofErrorId | qof_error_register (const gchar *err_message, gboolean use_file) |
Generate and register a new error. More... | |
void | qof_error_unregister (QofErrorId id) |
Unregister an error. More... | |
void | qof_error_set (QofSession *session, QofErrorId error) |
Add an error to the stack for this session. More... | |
void | qof_error_set_be (QofBackend *be, QofErrorId error) |
void | qof_error_clear (QofSession *session) |
clear the error stack for the session. More... | |
QofErrorId | qof_error_check_be (QofBackend *be) |
Check for errors. More... | |
QofErrorId | qof_error_check (QofSession *session) |
QofTime * | qof_error_get_time_be (QofBackend *be) |
Get the time of the most recent error. More... | |
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. More... | |
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. More... | |
const gchar * | qof_error_get_message (QofSession *session) |
Alternative for applications. | |
QofError supports the creation of new error codes (complete with error strings) along the lines of GdaError. Applications and backends can generate their own QofError values and register them with QofError. Any function can then set this error value and retrieve the error with qof_error_get_id or qof_error_get_message. The main advantage is that applications can set error states that are unrelated to the old QofBackendError values but retrieve all errors in the same manner.
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 | ) |
QofErrorId qof_error_check_be | ( | QofBackend * | be | ) |
Check for errors.
be | The backend to check. |
Definition at line 234 of file qoferror.c.
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 209 of file qoferror.c.
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 314 of file qoferror.c.
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 364 of file qoferror.c.
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 251 of file qoferror.c.
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 |
To use a different presentation of the filename or other customised strings, prepare the error message before registering it with QofError.
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 91 of file qoferror.c.
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 133 of file qoferror.c.
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 117 of file qoferror.c.