OpenEdge Development: Mobile Applications - Product ...

Client JavaScript code: Update
Accessing built-in CRUD operations
The following example illustrates calling assign( ) on a table reference in the JSDO
to update a record:
/* subscribe to event */
dsOrderEntry.subscribe('afterUpdate', onAfterUpdate);
var updatedDataObject = {City: 'Nashua'};
/* some code that would update a record and send it to the server */
var jsrecord = dsOrderEntry.ttCustomer.findById(myid);
dsOrderEntry.ttCustomer.assign( updatedDataObject );
dsOrderEntry.saveChanges();
function onAfterUpdate (jsdo , record , success , request ) {
if (success) {
/* for example, get the values updated by the server from the record
to redisplay */
var newValue = record.data.myField;
}
else {
if (request.response && request.response._errors &&
request.response._errors.length > 0){
var lenErrors = request.response._errors.length;
for (var idxError=0; idxError < lenErrors; idxError++) {
var errorEntry = request.response._errors[idxError];
var errorMsg = errorEntry._errorMsg;
var errorNum = errorEntry._errorNum;
/* handle error */
}
}
}
}
Notice that the sample code:
• Subscribes an event-handler function, onAfterUpdate, to the afterUpdate event
to enable error-checking and manipulation of the revised record.
• Calls findById( ) to retrieve the record to be updated, which becomes the
working record for the ttCustomer table, and changes the value of the City field
to Nashua. (The table reference could be omitted if ttCustomer were the only
temp-table in the dsOrderEntry ProDataSet.)
• Calls saveChanges( ) to execute UpdateOrderEntry( ) on the AppServer and
thereby synchronize the content of local storage with the database.
Delete operation
To delete an existing record from local storage on the client, you call the remove( )
method.
The remove( ) method can be called on either of the following:
• A table reference on the JSDO. When called on a table reference, assign( )
operates on the working record for that table.
• A specific JSRecord object. The example below uses this technique.
OpenEdge ® Development: Mobile Applications 111