OpenEdge Development: Mobile Applications - Product ...

saveChanges( ) method
saveChanges( ) method
Synchronizes to the AppServer all changes made to JSDO local storage since the last
call to the fill( ) or saveChanges( ) method. The saveChanges( ) method
completes this data synchronization by invoking appropriate built-in resource
operations on each changed record, one at a time, and in the following general order
of operation type:
1. "delete" — All record deletions are applied, one at a time across the network.
2. "create" — The creation of all new records is applied, one at a time across the
network.
3. "update" — Updates are applied to all modified records, one at a time across the
network.
The sending of changes for multiple operations on the same record is optimized, so the
fewest possible changes are sent to the AppServer. For example, if a record is
updated, then deleted in local storage, only the deletion is sent to the AppServer.
Note: In the current release, there is no batching of built-in record-change
operations. That is, the built-in delete operation is invoked over the network for
each deleted record, followed by the built-in create operation for each created
record, and finally by the built-in update operation for each updated record. So,
even for a ProDataSet, a built-in record operation executes over the network
only one record at a time and cannot be part of a transaction.
After execution, the working record for each temp-table referenced by the JSDO is not
set.
Return type: null
Applies to: progress.data.JSDO class
Syntax
saveChanges ( )
This method always executes asynchronously, and fires the following JSDO named
events, as required by JSDO changes, and shown in operational order:
1. beforeSaveChanges event
2. beforeDelete event
3. afterDelete event
4. beforeCreate event
5. afterCreate event
6. beforeUpdate event
7. afterUpdate event
8. afterSaveChanges event
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