background image
C H A P T E R 1 1
Data Storage and Retrieval
Using Newton Data Storage Objects
11-61
Copying Entries
11
The
EntryCopyXmit
global function and the
CopyEntriesXmit
soup method
enable you to copy entries from one soup to another and transmit appropriate
change notifications.
The following code fragment uses the
CopyEntriesXmit
soup method to copy
all the entries from a specified source soup into a specified destination soup. Note
that this method is defined only for soups, not for union soups. The following code
fragment uses the
GetMember
union soup method to retrieve the plain soup
constituent of a union soup from a specified store. The
GetMember
method never
returns
nil
; instead, it creates an empty member soup on the specified store if one
does not already exist:
// myUsoup member on internal store is the source soup
local myUSoup := GetUnionSoupAlways("myUSoup:mySig");
local sourceSoup := myUSoup:GetMember(GetStores()[0])
// myUsoup member on another store is the destination soup
local destSoup := myUSoup:GetMember(GetStores()[1]);
// copy all entries from source soup to dest soup
local cursor := sourceSoup:Query(nil);
if (cursor:CountEntries() <> 0) then
sourceSoup:CopyEntriesXmit(destSoup, '|MyApp:MySig|);
You can use the
EntryCopyXmit
function to copy an entry from a specified
source soup to a specified destination soup and transmit a soup change notification
message. Note that this function is defined only for soups, not for union soups. The
following code fragment uses the
GetSoup
store method to retrieve a specified
soup from its store. Because the
GetSoup
method returns
nil
when the soup to
be retrieved is not available, you must at least ensure that this result is non-
nil
before using it. The following code fragment actually goes one step further and
uses the
IsValid
soup method to test the validity of the
destSoup
soup in
additional ways:
local myUSoup := GetUnionSoupAlways("myUSoup:mySig");
// get all entries having 'hot in 'temperature slot
local cursor := myUSoup:Query({indexPath: 'temperature,
beginKey: 'hot
endKey: 'hot});
local destSoup := GetStores()[0]:GetSoup("mySoup:mySig");
// make sure we actually got a valid soup
if destSoup:IsValid() then
begin
// xmit a single notification after all changes are made
while e := cursor:Entry() do EntryCopyXmit(e,destSoup,nil);
XmitSoupChange(destSoup, '|MyApp:MySig|, 'whatThe, nil);
end;
© 2007-2017, o7 studio » при воспроизведении материала сайта ссылка обязательна