QOF  0.7.5

Files

file  qofsession.h
 Encapsulates a connection to a backend (persistent store)
 

Macros

#define QOF_MOD_SESSION   "qof-session"
 
#define QOF_STDOUT   "file:"
 Allow session data to be printed to stdout. More...
 

Typedefs

typedef struct _QofSession QofSession
 
typedef void(* QofPercentageFunc )(const gchar *message, gdouble percent)
 

Functions

QofSessionqof_session_new (void)
 
void qof_session_destroy (QofSession *session)
 
void qof_session_swap_data (QofSession *session_1, QofSession *session_2)
 
void qof_session_begin (QofSession *session, const gchar *book_id, gboolean ignore_lock, gboolean create_if_nonexistent)
 
void qof_session_load (QofSession *session, QofPercentageFunc percentage_func)
 
void qof_session_add_book (QofSession *session, QofBook *book)
 
QofBookqof_session_get_book (QofSession *session)
 
const gchar * qof_session_get_file_path (QofSession *session)
 
const gchar * qof_session_get_url (QofSession *session)
 
gboolean qof_session_not_saved (QofSession *session)
 
gboolean qof_session_save_may_clobber_data (QofSession *session)
 
void qof_session_save (QofSession *session, QofPercentageFunc percentage_func)
 
void qof_session_end (QofSession *session)
 
void qof_session_add_close_hook (GFunc fn, gpointer data)
 
void qof_session_call_close_hooks (QofSession *session)
 

Copying entities between sessions.

Only certain backends can cope with selective copying of entities and only fully defined QOF entities can be copied between sessions - see the QOF Serialisation Format (QSF) documentation (::qsf_write_file) for more information.

The recommended backend for the new session is QSF or a future SQL backend. Using any of these entity copy functions sets a flag in the backend that this is now a partial QofBook. See Reference: Referring to entities outside a partial book.. When you save a session containing a partial QofBook, the session will check that the backend is able to handle the partial book. If not, the backend will be replaced by one that can handle partial books, preferably one using the same ::access_method. Currently, this means that a book using the GnuCash XML v2 file backend will be switched to QSF.

Copied entities are identical to the source entity, all parameters defined with QofAccessFunc and QofSetterFunc in QOF are copied and the ::GUID of the original QofEntity is set in the new entity. Sessions containing copied entities are intended for use as mechanisms for data export.

It is acceptable to add entities to new_session in batches. Note that any of these calls will fail if an entity already exists in new_session with the same GUID as any entity to be copied.

To merge a whole QofBook or where there is any possibility of collisions or requirement for user intervention, see Merge: Merging QofBook structures

gboolean qof_entity_copy_to_session (QofSession *new_session, QofEntity *original)
 Copy a single QofEntity to another session. More...
 
gboolean qof_entity_copy_list (QofSession *new_session, GList *entity_list)
 Copy a GList of entities to another session. More...
 
gboolean qof_entity_copy_coll (QofSession *new_session, QofCollection *entity_coll)
 Copy a QofCollection of entities. More...
 
gboolean qof_entity_copy_coll_r (QofSession *new_session, QofCollection *coll)
 Recursively copy a collection of entities to a session. More...
 
gboolean qof_entity_copy_one_r (QofSession *new_session, QofEntity *ent)
 Recursively copy a single entity to a new session. More...
 

Event Handling

gboolean qof_session_events_pending (QofSession *session)
 
gboolean qof_session_process_events (QofSession *session)
 

Detailed Description

The QOF Session encapsulates a connection to a storage backend. That is, it manages the connection to a persistant data store; whereas the backend is the thing that performs the actual datastore access.

This class provides several important services:

1) It resolves and loads the appropriate backend, based on the URL.

2) It reports backend errors (e.g. network errors, storage corruption errors) through a single, backend-independent API.

3) It reports non-error events received from the backend.

4) It helps manage global dataset locks. For example, for the file backend, the lock prevents multiple users from editing the same file at the same time, thus avoiding lost data due to race conditions. Thus, an open session implies that the associated file is locked.

5) Misc utilities, such as a search path for the file to be edited, and/or other URL resolution utilities. This should simplify install & maintenance problems for naive users who may not have a good grasp on what a file system is, or where they want to keep their data files.

6) In the future, this class is probably a good place to manage a portion of the user authentication process, and hold user credentials/cookies/keys/tokens. This is because at the coarsest level, authorization can happen at the datastore level: i.e. does this user even have the authority to connect to and open this datastore?

A brief note about books & sessions: A book encapsulates the datasets manipulated by QOF. A book holds the actual data. By contrast, the session mediates the connection between a book (the thing that lives in virtual memory in the local process) and the datastore (the place where book data lives permanently, e.g., file, database).

In the current design, a session may hold multiple books. For now, exactly what this means is somewhat vague, and code in various places makes some implicit assumptions: first, only one book is 'current' and open for editing. Next, its assumed that all of the books in a session are related in some way. i.e. that they are all earlier accounting periods of the currently open book. In particular, the backends probably make that assumption, in order to store the different accounting periods in a clump so that one can be found, given another.

If you want multiple books that are unrelated to each other, use multiple sessions.

The session now calls QofBackendProvider->check_data_type to check that the incoming path contains data that the backend provider can open. The backend provider should also check if it can contact it's storage media (disk, network, server, etc.) and abort if it can't. Malformed file URL's would be handled the same way.

Macro Definition Documentation

#define QOF_STDOUT   "file:"

Allow session data to be printed to stdout.

book_id can't be NULL and we do need to have an access_method, so use one to solve the other.

To print a session to stdout, use qof_session_begin. Example:

qof_session_begin(session,QOF_STDOUT,TRUE,FALSE);

When you call qof_session_save(session, NULL), the output will appear on stdout and can be piped or redirected to other processes.

Currently, only the QSF backend supports writing to stdout, other backends may return a ::QofBackendError.

Definition at line 385 of file qofsession.h.

Typedef Documentation

typedef void(* QofPercentageFunc)(const gchar *message, gdouble percent)

The qof_session_load() method causes the QofBook to be made ready to to use with this URL/datastore. When the URL points at a file, then this routine would load the data from the file. With remote backends, e.g. network or SQL, this would load only enough data to make the book actually usable; it would not cause all of the data to be loaded.

XXX the current design tries to accomodate multiple calls to 'load' for each session, each time wiping out the old books; this seems wrong to me, and should be restricted to allow only one load per session.

Definition at line 168 of file qofsession.h.

Function Documentation

gboolean qof_entity_copy_coll ( QofSession new_session,
QofCollection entity_coll 
)

Copy a QofCollection of entities.

The QofBook in the new_session must not contain any entities with the same GUID as any entities in the collection - there is no support for handling collisions - instead, use Merge: Merging QofBook structures

Parameters
new_session- the target session
entity_coll- a QofCollection of any QofIdType.
Returns
FALSE, without copying, if new_session contains any entities with the same GUID. Otherwise TRUE.

Definition at line 710 of file qofsession.c.

712 {
713  QofEntityCopyData qecd;
714 
715  g_return_val_if_fail (new_session, FALSE);
716  if (!entity_coll)
717  {
718  return FALSE;
719  }
721  qecd.param_list = NULL;
722  qecd.new_session = new_session;
723  qof_book_set_partial (qof_session_get_book (qecd.new_session));
724  qof_collection_foreach (entity_coll, qof_entity_coll_foreach, &qecd);
726  qof_entity_param_cb, &qecd);
727  qof_collection_foreach (entity_coll, qof_entity_coll_copy, &qecd);
728  if (qecd.param_list != NULL)
729  {
730  g_slist_free (qecd.param_list);
731  }
732  qof_event_resume ();
733  return TRUE;
734 }
gboolean qof_entity_copy_coll_r ( QofSession new_session,
QofCollection coll 
)

Recursively copy a collection of entities to a session.

Note
This function creates a partial QofBook. See qof_entity_copy_to_session for more information.

The QofBook in the new_session must not contain any entities with the same GUID as any entities to be copied - there is no support for handling collisions - instead, use Merge: Merging QofBook structures

Objects can be defined solely in terms of QOF data types or as a mix of data types and other objects, which may in turn include other objects. These references can be copied recursively down to the third level. See QofEntityReference.

Note
This is a deep recursive copy - every referenced entity is copied to the new session, including all parameters. The starting point is all entities in the top level collection. It can take some time.
Parameters
collA QofCollection of entities that may or may not have references.
new_sessionThe QofSession to receive the copied entities.
Returns
TRUE on success; if any individual copy fails, returns FALSE. Note : Some entities may have been copied successfully even if one of the references fails to copy.

Definition at line 884 of file qofsession.c.

885 {
886  struct recurse_s store;
887  gboolean success;
888 
889  if ((!new_session) || (!coll))
890  {
891  return FALSE;
892  }
893  store.session = new_session;
894  success = TRUE;
895  store.success = success;
896  store.ent_list = NULL;
897  store.ref_list =
899  success = qof_entity_copy_coll (new_session, coll);
900  if (success)
901  {
902  qof_collection_foreach (coll, recurse_ent_cb, &store);
903  }
904  return success;
905 }
gboolean qof_entity_copy_list ( QofSession new_session,
GList *  entity_list 
)

Copy a GList of entities to another session.

The QofBook in the new_session must not contain any entities with the same GUID as any of the source entities - there is no support for handling collisions, instead use Merge: Merging QofBook structures

Note that the GList (e.g. from qof_sql_query_run) can contain QofEntity pointers of any QofIdType, in any sequence. As long as all members of the list are QofEntity*, and all GUID's are unique, the list can be copied.

Parameters
new_session- the target session
entity_list- a GList of QofEntity pointers of any type(s).
Returns
FALSE, without copying, if new_session contains any entities with the same GUID. Otherwise TRUE.

Definition at line 688 of file qofsession.c.

689 {
690  QofEntityCopyData *qecd;
691 
692  if (!new_session || !entity_list)
693  return FALSE;
694  ENTER (" list=%d", g_list_length (entity_list));
695  qecd = g_new0 (QofEntityCopyData, 1);
697  qecd->param_list = NULL;
698  qecd->new_session = new_session;
699  qof_book_set_partial (qof_session_get_book (new_session));
700  g_list_foreach (entity_list, qof_entity_list_foreach, qecd);
701  qof_event_resume ();
702  if (qecd->error)
703  PWARN (" some/all entities in the list could not be copied.");
704  g_free (qecd);
705  LEAVE (" ");
706  return TRUE;
707 }
gboolean qof_entity_copy_one_r ( QofSession new_session,
QofEntity ent 
)

Recursively copy a single entity to a new session.

Copy the single entity and all referenced entities to the second level.

Only entities that are directly referenced by the top level entity are copied.

This is a deep copy - all parameters of all referenced entities are copied. If the top level entity has no references, this is identical to qof_entity_copy_to_session.

Parameters
entA single entity that may or may not have references.
new_sessionThe QofSession to receive the copied entities.
Returns
TRUE on success; if any individual copy fails, returns FALSE. Note : Some entities may have been copied successfully even if one of the references fails to copy.

Definition at line 908 of file qofsession.c.

909 {
910  struct recurse_s store;
911  QofCollection *coll;
912  gboolean success;
913 
914  if ((!new_session) || (!ent))
915  {
916  return FALSE;
917  }
918  store.session = new_session;
919  success = TRUE;
920  store.success = success;
921  store.ref_list = qof_class_get_referenceList (ent->e_type);
922  success = qof_entity_copy_to_session (new_session, ent);
923  if (success == TRUE)
924  {
925  coll =
926  qof_book_get_collection (qof_session_get_book (new_session),
927  ent->e_type);
928  if (coll)
929  {
930  qof_collection_foreach (coll, recurse_ent_cb, &store);
931  }
932  }
933  return success;
934 }
gboolean qof_entity_copy_to_session ( QofSession new_session,
QofEntity original 
)

Copy a single QofEntity to another session.

Checks first that no entity in the session book contains the GUID of the source entity.

Parameters
new_session- the target session
original- the QofEntity* to copy
Returns
FALSE without copying if the session contains an entity with the same GUID already, otherwise TRUE.

Definition at line 656 of file qofsession.c.

657 {
658  QofEntityCopyData qecd;
659  QofInstance *inst;
660  QofBook *book;
661 
662  if (!new_session || !original)
663  return FALSE;
664  if (qof_entity_guid_match (new_session, original))
665  return FALSE;
666  if (!qof_object_compliance (original->e_type, TRUE))
667  return FALSE;
669  qecd.param_list = NULL;
670  book = qof_session_get_book (new_session);
671  qecd.new_session = new_session;
672  qof_book_set_partial (book);
673  inst =
674  (QofInstance *) qof_object_new_instance (original->e_type, book);
675  qecd.to = &inst->entity;
676  qecd.from = original;
677  qof_entity_set_guid (qecd.to, qof_entity_get_guid (original));
678  qof_class_param_foreach (original->e_type, qof_entity_param_cb, &qecd);
679  if (g_slist_length (qecd.param_list) == 0)
680  return FALSE;
681  g_slist_foreach (qecd.param_list, qof_entity_foreach_copy, &qecd);
682  g_slist_free (qecd.param_list);
683  qof_event_resume ();
684  return TRUE;
685 }
void qof_session_add_book ( QofSession session,
QofBook book 
)

The qof_session_add_book() allows additional books to be added to a session. XXX Under construction, clarify the following when done: XXX There must already be an open book in the session already!? XXX Only one open book at a time per session is allowed!? XXX each book gets its own unique backend ???

Definition at line 148 of file qofsession.c.

149 {
150  GList *node;
151  if (!session)
152  return;
153 
154  ENTER (" sess=%p book=%p", session, addbook);
155 
156  /* See if this book is already there ... */
157  for (node = session->books; node; node = node->next)
158  {
159  QofBook *book = node->data;
160  if (addbook == book)
161  return;
162  }
163 
164  if ('y' == addbook->book_open)
165  {
166  /* hack alert -- someone should free all the books in the list,
167  * but it should probably not be us ... since the books backends
168  * should be shutdown first, etc */
169 /* XXX this should probably be an error XXX */
170  g_list_free (session->books);
171  session->books = g_list_append (NULL, addbook);
172  }
173  else
174  {
175 /* XXX Need to tell the backend to add a book as well */
176  session->books = g_list_append (session->books, addbook);
177  }
178 
179  qof_book_set_backend (addbook, session->backend);
180  LEAVE (" ");
181 }
void qof_session_add_close_hook ( GFunc  fn,
gpointer  data 
)

Register a function to be called just before a session is closed.

Parameters
fnThe function to be called. The function definition must be func(gpointer session, gpointer user_data);
dataThe data to be passed to the function.

Definition at line 69 of file qofsession.c.

70 {
71  GHook *hook;
72 
73  if (session_closed_hooks == NULL)
74  {
75  session_closed_hooks = malloc (sizeof (GHookList)); /* LEAKED */
76  g_hook_list_init (session_closed_hooks, sizeof (GHook));
77  }
78 
79  hook = g_hook_alloc (session_closed_hooks);
80  if (!hook)
81  return;
82 
83  hook->func = (GHookFunc) fn;
84  hook->data = data;
85  g_hook_append (session_closed_hooks, hook);
86 }
void qof_session_begin ( QofSession session,
const gchar *  book_id,
gboolean  ignore_lock,
gboolean  create_if_nonexistent 
)

The qof_session_begin () method begins a new session. It takes as an argument the book id. The book id must be a string in the form of a URI/URL. The access method specified depends on the loaded backends. In the absence of a customised backend, only QSF XML would be accepted). Paths may be relative or absolute. If the path is relative; that is, if the argument is "file:somefile.xml" then the current working directory is assumed. Customised backends can choose to search other, application-specific, directories as well.

The 'ignore_lock' argument, if set to TRUE, will cause this routine to ignore any global-datastore locks (e.g. file locks) that it finds. If set to FALSE, then file/database-global locks will be tested and obeyed.

If the datastore exists, can be reached (e.g over the net), connected to, opened and read, and a lock can be obtained then a lock will be obtained. Note that multi-user datastores (e.g. the SQL backend) typically will not need to get a global lock, and thus, the user will not be locked out. That's the whole point of 'multi-user'.

If the file/database doesn't exist, and the create_if_nonexistent flag is set to TRUE, then the database is created.

If an error occurs, it will be pushed onto the session error stack, and that is where it should be examined.

Definition at line 1057 of file qofsession.c.

1059 {
1060  gchar *p, *access_method;
1061 
1062  if (!session)
1063  return;
1064 
1065  ENTER (" sess=%p ignore_lock=%d, book-id=%s",
1066  session, ignore_lock, book_id ? book_id : "(null)");
1067 
1068  /* Clear the error condition of previous errors */
1069  qof_error_clear (session);
1070 
1071  /* Check to see if this session is already open */
1072  if (session->book_id)
1073  {
1075  (_("This book appears to be open already."), FALSE));
1076  LEAVE (" push error book is already open ");
1077  return;
1078  }
1079 
1080  if (!book_id)
1081  {
1082  LEAVE (" using stdout");
1083  return;
1084  }
1085 
1086  /* Store the session URL */
1087  session->book_id = g_strdup (book_id);
1088 
1089  /* destroy the old backend */
1090  qof_session_destroy_backend (session);
1091 
1092  /* Look for something of the form of "file:/", "http://" or
1093  * "postgres://". Everything before the colon is the access
1094  * method. Load the first backend found for that access method.
1095  */
1096  p = strchr (book_id, ':');
1097  if (p)
1098  {
1099  access_method = g_strdup (book_id);
1100  p = strchr (access_method, ':');
1101  *p = 0;
1102  qof_session_load_backend (session, access_method);
1103  g_free (access_method);
1104  }
1105  else
1106  {
1107  /* If no colon found, assume it must be a file-path */
1108  qof_session_load_backend (session, "file");
1109  }
1110 
1111  /* No backend was found. That's bad. */
1112  if (NULL == session->backend)
1113  {
1114  gchar * msg;
1115 
1116  msg = g_strdup_printf (_("Unable to locate a "
1117  "suitable backend for '%s' - please check "
1118  "you have specified an access method "
1119  "like file: or sqlite:"), book_id);
1121  (msg, FALSE));
1122  DEBUG (" msg=%s", msg);
1123  LEAVE (" BAD: no backend: sess=%p book-id=%s",
1124  session, book_id ? book_id : "(null)");
1125  g_free (msg);
1126  return;
1127  }
1128 
1129  /* If there's a begin method, call that. */
1130  if (session->backend->session_begin)
1131  {
1132  (session->backend->session_begin) (session->backend, session,
1133  session->book_id, ignore_lock, create_if_nonexistent);
1134  PINFO (" Done running session_begin on backend");
1135  if (qof_error_check(session) != QOF_SUCCESS)
1136  {
1137  g_free (session->book_id);
1138  session->book_id = NULL;
1139  LEAVE (" backend error ");
1140  return;
1141  }
1142  }
1143  qof_error_clear (session);
1144  LEAVE (" sess=%p book-id=%s", session, book_id ? book_id : "(null)");
1145 }
void qof_session_call_close_hooks ( QofSession session)

Call all registered session close hooks, informing them that the specified session is about to be closed.

Parameters
sessionA pointer to the session being closed.

Definition at line 89 of file qofsession.c.

90 {
91  GHook *hook;
92  GFunc fn;
93 
94  if (session_closed_hooks == NULL)
95  return;
96 
97  hook = g_hook_first_valid (session_closed_hooks, FALSE);
98  while (hook)
99  {
100  fn = (GFunc) hook->func;
101  fn (session, hook->data);
102  hook = g_hook_next_valid (session_closed_hooks, hook, FALSE);
103  }
104 }
void qof_session_end ( QofSession session)

The qof_session_end() method will release the session lock. For the file backend, it will not save the data to a file. Thus, this method acts as an "abort" or "rollback" primitive. However, for other backends, such as the sql backend, the data would have been written out before this, and so this routines wouldn't roll-back anything; it would just shut the connection.

Definition at line 1399 of file qofsession.c.

1400 {
1401  if (!session)
1402  return;
1403 
1404  ENTER (" sess=%p book_id=%s", session, session->book_id
1405  ? session->book_id : "(null)");
1406 
1407  /* close down the backend first */
1408  if (session->backend && session->backend->session_end)
1409  {
1410  (session->backend->session_end) (session->backend);
1411  }
1412 
1413  qof_error_clear (session);
1414 
1415  g_free (session->book_id);
1416  session->book_id = NULL;
1417 
1418  LEAVE (" sess=%p book_id=%s", session, session->book_id
1419  ? session->book_id : "(null)");
1420 }
gboolean qof_session_events_pending ( QofSession session)

The qof_session_events_pending() method will return TRUE if the backend has pending events which must be processed to bring the engine up to date with the backend.

Definition at line 1492 of file qofsession.c.

1493 {
1494  if (!session)
1495  return FALSE;
1496  if (!session->backend)
1497  return FALSE;
1498  if (!session->backend->events_pending)
1499  return FALSE;
1500 
1501  return session->backend->events_pending (session->backend);
1502 }
const gchar* qof_session_get_file_path ( QofSession session)

The qof_session_get_file_path() routine returns the fully-qualified file path for the session. That is, if a relative or partial filename was for the session, then it had to have been fully resolved to open the session. This routine returns the result of this resolution. The path is always guaranteed to reside in the local file system, even if the session itself was opened as a URL. (currently, the filepath is derived from the url by substituting commas for slashes).

The qof_session_get_url() routine returns the url that was opened. URL's for local files take the form of file:/some/where/some/file.gml

Definition at line 192 of file qofsession.c.

193 {
194  if (!session)
195  return NULL;
196  if (!session->backend)
197  return NULL;
198  return session->backend->fullpath;
199 }
gboolean qof_session_not_saved ( QofSession session)

The qof_session_not_saved() subroutine will return TRUE if any data in the session hasn't been saved to long-term storage.

gboolean qof_session_process_events ( QofSession session)

The qof_session_process_events() method will process any events indicated by the qof_session_events_pending() method. It returns TRUE if the engine was modified while engine events were suspended.

Definition at line 1505 of file qofsession.c.

1506 {
1507  if (!session)
1508  return FALSE;
1509  if (!session->backend)
1510  return FALSE;
1511  if (!session->backend->process_events)
1512  return FALSE;
1513 
1514  return session->backend->process_events (session->backend);
1515 }
void qof_session_save ( QofSession session,
QofPercentageFunc  percentage_func 
)

The qof_session_save() method will commit all changes that have been made to the session. For the file backend, this is nothing more than a write to the file of the current AccountGroup & etc. For the SQL backend, this is typically a no-op (since all data has already been written out to the database.

Todo:
check the access_method too, not in scope here, yet.

Definition at line 1245 of file qofsession.c.

1247 {
1248  GList *node;
1249  QofBackend *be;
1250  gboolean partial, change_backend;
1251  QofBackendProvider *prov;
1252  GSList *p;
1253  QofBook *book, *abook;
1254  gint num;
1255  gchar *msg, *book_id;
1256 
1257  if (!session)
1258  return;
1259  ENTER (" sess=%p book_id=%s",
1260  session, session->book_id ? session->book_id : "(null)");
1261  /* Partial book handling. */
1262  book = qof_session_get_book (session);
1263  partial =
1264  (gboolean)
1265  GPOINTER_TO_INT (qof_book_get_data (book, PARTIAL_QOFBOOK));
1266  change_backend = FALSE;
1267  msg = g_strdup_printf (" ");
1268  book_id = g_strdup (session->book_id);
1269  if (partial == TRUE)
1270  {
1271  if (session->backend && session->backend->provider)
1272  {
1273  prov = session->backend->provider;
1274  if (TRUE == prov->partial_book_supported)
1275  {
1276  /* if current backend supports partial, leave alone. */
1277  change_backend = FALSE;
1278  }
1279  else
1280  {
1281  change_backend = TRUE;
1282  }
1283  }
1284  /* If provider is undefined, assume partial not supported. */
1285  else
1286  {
1287  change_backend = TRUE;
1288  }
1289  }
1290  if (change_backend == TRUE)
1291  {
1292  qof_session_destroy_backend (session);
1293  if (NULL == provider_list)
1294  {
1295  for (num = 0; backend_list[num].filename != NULL; num++)
1296  {
1297  qof_load_backend_library (backend_list[num].libdir,
1298  backend_list[num].filename,
1299  backend_list[num].init_fcn);
1300  }
1301  }
1302  p = g_slist_copy (provider_list);
1303  while (p != NULL)
1304  {
1305  prov = p->data;
1306  if (TRUE == prov->partial_book_supported)
1307  {
1309  /* if((TRUE == prov->partial_book_supported) &&
1310  (0 == strcasecmp (access_method, prov->access_method)))
1311  { */
1312  if (NULL == prov->backend_new)
1313  continue;
1314  /* Use the providers creation callback */
1315  session->backend = (*(prov->backend_new)) ();
1316  session->backend->provider = prov;
1317  if (session->backend->session_begin)
1318  {
1319  /* Call begin - backend has been changed,
1320  so make sure a file can be written,
1321  use ignore_lock and create_if_nonexistent */
1322  g_free (session->book_id);
1323  session->book_id = NULL;
1324  (session->backend->session_begin) (session->backend,
1325  session, book_id, TRUE, TRUE);
1326  PINFO
1327  (" Done running session_begin on changed backend");
1328  if (qof_error_check (session) != QOF_SUCCESS)
1329  {
1330  g_free (session->book_id);
1331  session->book_id = NULL;
1332  LEAVE (" changed backend error");
1333  return;
1334  }
1335  }
1336  /* Tell the books about the backend that they'll be using. */
1337  for (node = session->books; node; node = node->next)
1338  {
1339  book = node->data;
1340  qof_book_set_backend (book, session->backend);
1341  }
1342  p = NULL;
1343  }
1344  if (p)
1345  {
1346  p = p->next;
1347  }
1348  }
1349  if (!session->backend)
1350  {
1351  msg = g_strdup_printf (" failed to load backend");
1353  (_("Failed to load backend, no suitable handler."),
1354  FALSE));
1355  return;
1356  }
1357  }
1358  /* If there is a backend, and the backend is reachable
1359  * (i.e. we can communicate with it), then synchronize with
1360  * the backend. If we cannot contact the backend (e.g.
1361  * because we've gone offline, the network has crashed, etc.)
1362  * then give the user the option to save to the local disk.
1363  *
1364  * hack alert -- FIXME -- XXX the code below no longer
1365  * does what the words above say. This needs fixing.
1366  */
1367  be = session->backend;
1368  if (be)
1369  {
1370  for (node = session->books; node; node = node->next)
1371  {
1372  abook = node->data;
1373  /* if invoked as SaveAs(), then backend not yet set */
1374  qof_book_set_backend (abook, be);
1375  be->percentage = percentage_func;
1376  if (be->sync)
1377  (be->sync) (be, abook);
1378  }
1379  /* If we got to here, then the backend saved everything
1380  * just fine, and we are done. So return. */
1381  /* Return the book_id to previous value. */
1382  qof_error_clear (session);
1383  LEAVE (" Success");
1384  return;
1385  }
1386  else
1387  {
1388  msg = g_strdup_printf (" failed to load backend");
1390  (_("Failed to load backend, no suitable handler."),
1391  FALSE));
1392  }
1393  LEAVE (" error -- No backend!");
1394 }
gboolean qof_session_save_may_clobber_data ( QofSession session)

Allows the backend to warn the user if a dataset already exists.

Definition at line 1232 of file qofsession.c.

1233 {
1234  if (!session)
1235  return FALSE;
1236  if (!session->backend)
1237  return FALSE;
1238  if (!session->backend->save_may_clobber_data)
1239  return FALSE;
1240 
1241  return (*(session->backend->save_may_clobber_data)) (session->backend);
1242 }
void qof_session_swap_data ( QofSession session_1,
QofSession session_2 
)

The qof_session_swap_data () method swaps the book of the two given sessions. It is useful for 'Save As' type functionality.

Definition at line 1458 of file qofsession.c.

1459 {
1460  GList *books_1, *books_2, *node;
1461 
1462  if (session_1 == session_2)
1463  return;
1464  if (!session_1 || !session_2)
1465  return;
1466 
1467  ENTER (" sess1=%p sess2=%p", session_1, session_2);
1468 
1469  books_1 = session_1->books;
1470  books_2 = session_2->books;
1471 
1472  session_1->books = books_2;
1473  session_2->books = books_1;
1474 
1475  for (node = books_1; node; node = node->next)
1476  {
1477  QofBook *book_1 = node->data;
1478  qof_book_set_backend (book_1, session_2->backend);
1479  }
1480  for (node = books_2; node; node = node->next)
1481  {
1482  QofBook *book_2 = node->data;
1483  qof_book_set_backend (book_2, session_1->backend);
1484  }
1485 
1486  LEAVE (" ");
1487 }