OpenEdge Development: Mobile Applications - Product ...

JSDO overview
If a method leaves a working record, you can reference the field values of the record
object using field reference properties on the table reference, as described in the
previous section. You can also use the record property on the table reference to return
a reference to a JSRecord object for the working record that you can reference directly
or store separately to access the record object later. A JSRecord object provides a
data property that references a separate JavaScript object with the actual field
reference properties for the record. Also as a convenience, if the JSDO supports only
a single temp-table, you can access the record property for the working record directly
on the JSDO reference itself.
So, using the previous example with ttCustomer, where it is the only temp-table in
local storage, you can access the Name field using a JSRecord object reference in the
following ways:
var custName = dsOrderEntry.record.data.Name; // Single temp-table only
var custName = dsOrderEntry.ttCustomer.record.data.Name;
var custRecord = dsOrderEntry.ttCustomer.record; // Stored for later reference
var custName = custRecord.data.Name;
Once stored, an existing record object remains available using the stored JSRecord
reference even when it is no longer the working record for the temp-table. Note that
using the data property to write a value to a field is not recommended, because the
record object is not marked as changed in local storage and won’t be updated on the
AppServer. To update a field value on a JSRecord object reference so the change is
made on the AppServer, call the assign( ) method directly on the JSRecord
reference.
Note: One reason to use the record.data property on a table reference to read a
field value is when the field has the same name as a JSDO method that you
can call on a table reference.
Caution: Because the record object is not marked as changed in local storage, never
use the data property on a JSRecord reference to update the value of a field.
The change will never be posted to AppServer. Use the data property to read
the field value only.
Record IDs
One difference between the JavaScript record objects in JSDO local storage and the
temp-table records that they represent is that each record object contains a record ID.
This is an internal field that uniquely identifies the record in JSDO local storage. This
record ID has no relationship to the internal RECID and ROWID values maintained for the
records of an OpenEdge database. Instead, this record ID is used by the client JSDO
services built into the Mobile App Builder, and also by the progress.ui.UIHelper
class, to map the record objects in JSDO local storage to the HTML elements of Mobile
Apps. Also, you can retrieve this record ID from any record object in local storage and
store it for future reference in order to efficiently retrieve the record object, again, from
local storage.
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