Change Class of Settlement Record by taking the value from Line item of another Record.

//Info: JOIN-205

var test = dataObj.values.custbody_celigo_etail_order_id
log.debug("etailId",test)
                var mainRecord = dataObj.values.internalid[0].value
                log.debug("recordInternalid",mainRecord)

                //search for invoice order id
                   var invoiceSearchObj = search.create({
                    type: "invoice",
                    filters:
                        [
                            ["type","anyof","CustInvc"],
                            "AND",
                            ["custbody_celigo_etail_order_id","is",test],
                            "AND",
                            ["mainline","is","T"]
                        ],
                    columns:
                        [
                            search.createColumn({name: "internalid", label: "Internal ID"})
                        ]
                });
                var searchResult = invoiceSearchObj.run().getRange({
                    start: 0,
                    end: 1
                });
    var internal_id = searchResult[0].getValue({name: "internalid", label: "Internal Id"})
     log.debug('internalId Invoice',internal_id)

                //load invoice order
                var invoice_rec = record.load({
                    type: record.Type.INVOICE,
                    id: internal_id,
                    isDynamic: true,
                })
                var class_id;
                for(i=0;i<1;i++)
                {
                    invoice_rec.selectLine({
                        sublistId: 'item',
                        line: i
                    });
                    class_id = invoice_rec.getCurrentSublistValue({
                        sublistId: 'item',
                        fieldId: 'class',
                    });
                    log.debug("classId",class_id)
                }
                var recType= dataObj.recordType
                log.debug("recordType",recType)
                var custRec = record.load({
                    type: recType.toString(),
                    id: mainRecord,
                    isDynamic: true
                })
                log.debug("record",custRec)
                var mainClass = custRec.getValue({
                    fieldId: 'class'
                })
                log.debug("mainClass_id",mainClass)
                if (mainClass !== class_id)
                {
                    log.debug("final")
                    custRec.setValue({
                        fieldId: 'class',
                        value: class_id
                    })
                    custRec.save()

                }

Note:
This part is added under Reduce context stage in MapReduce script.
‘dataObj’ , which is mentioned initially holds the value of records that the user chooses. This can be done in getInputData stage.