SQLcatalog: Add function to get normal or deferred connection id for catalog

Also, we don't need to look for `transactionless` connection-id here,
as we don't use them in catalog methods.
And, update the files where we can use the new function.

product/ERP5/Document/Inventory.py

@@ -115,12 +115,7 @@ class Inventory(Delivery):
     if sql_catalog_id is not None:
       # try to get connection used in the catalog
       catalog = portal.portal_catalog[sql_catalog_id]
-      for method in catalog.objectValues():
-        if method.meta_type == "Z SQL Method":
-          if 'deferred' not in method.connection_id \
-               and 'transactionless' not in method.connection_id:
-            connection_id = method.connection_id
-            break
+      connection_id = catalog.getConnectionId()
 
     default_inventory_calculation_list = ({ "inventory_params" : {"section": self.getDestinationSection(),
                                                                   "node" : self.getDestination(),

product/ERP5Catalog/Tool/ArchiveTool.py

@@ -126,16 +126,9 @@ class ArchiveTool(BaseTool):
     # Guess connection id from current catalog
     source_catalog = portal_catalog.getSQLCatalog()
     source_catalog_id = source_catalog.getId()
-    if source_connection_id is None or source_deferred_connection_id is None:
-      for method in source_catalog.objectValues():
-        if method.meta_type == "Z SQL Method":
-          if source_deferred_connection_id is None and 'deferred' in method.connection_id:
-            source_deferred_connection_id = method.connection_id
-          elif source_connection_id is None and 'transactionless' not in method.connection_id:
-            source_connection_id = method.connection_id
-          if source_connection_id is not None and \
-             source_deferred_connection_id is not None:
-            break
+
+    source_connection_id = source_catalog.getConnectionId()
+    source_deferred_connection_id = source_catalog.getConnectionId(deferred=True)
 
     if source_connection_id is None or source_deferred_connection_id is None:
       raise ValueError, "Unable to determine connection id for the current catalog"

product/ZSQLCatalog/SQLCatalog.py

@@ -2820,6 +2820,18 @@ class Catalog(Folder,
       return filter_dict
     return None
 
+  security.declarePublic('getConnectionId')
+  def getConnectionId(self, deferred=False):
+    """
+    Returns the 'normal' connection being used by the SQL Method(s) in this
+    catalog.
+    If 'deferred' is True, then returns the deferred connection
+    """
+    for method in self.objectValues():
+      if method.meta_type == 'Z SQL Method':
+        if ('deferred' in method.connection_id) == deferred:
+          return method.connection_id
+
   security.declarePrivate('getFilterableMethodList')
   def getFilterableMethodList(self):
     """