Using UIBuilder in SSRS contract class

Hi, Below sample code used to get lookups.

In this scenario, i need to get itemid lookup based on Invoice id selected.

UIBuilder class

1. public class testUIBuilder extends SysOperationAutomaticUIBuilder
   {
   testContract contract;
   DialogField dialogInvoiceId;
   DialogField dialogItemId;
   }
2. public void build()
   {
   Dialog dialogLocal = this.dialog();
   contract = this.dataContractObject();
   this.addDialogField(methodStr(testContract,parmInvoiceId), contract);
   this.addDialogField(methodStr(testContract,parmItemId), contract);
   }
3. public void getFromDialog()
   {
   contract = this.dataContractObject();
   super();
   }
4. public void initializeFields()
   {
   contract = this.dataContractObject();
   }
5. public void lookupItem(FormStringControl _control)
   {
   Query query = new Query();
   QueryBuildDataSource queryBuildDataSource, queryBuildDataSource1;
   SysTableLookup sysTableLookup = SysTableLookup::newParameters(tablenum(CustInvoiceTrans), _control);
   ;

   sysTableLookup.addLookupfield(fieldnum(CustInvoiceTrans, ItemId),true);

    

   queryBuildDataSource = query.addDataSource(tablenum(CustInvoiceTrans));

   queryBuildDataSource1 = queryBuildDataSource.addDataSource(tablenum(CustInvoiceTrans));

   queryBuildDataSource1.addRange(fieldnum(CustInvoiceTrans, InvoiceId)).value(queryvalue(dialogInvoiceId.value()));

   sysTableLookup.parmQuery(query);

   sysTableLookup.performFormLookup();
   }

6. public void postBuild()
   {
   ;
   super();
   dialogInvoiceId = this.bindInfo().getDialogField(
   this.dataContractObject(),
   methodStr(testContract,parmInvoiceId));

   dialogItemId = this.bindInfo().getDialogField(
   this.dataContractObject(),
   methodStr(testContract,parmItemId));
   // register override method for lookup customer
   dialogItemId.registerOverrideMethod(methodStr(FormStringControl, lookup), methodStr(testUIBuilder,lookupItem),this);

   }

7. public void postRun()
   {
   Dialog dialogLocal = this.dialog();
   super();
   // This method should be called in order to handle events on dialogs.
   dialogLocal.dialogForm().formRun().controlMethodOverload(false);
   }

Contract class

1. [
   DataContractAttribute,
   SysOperationContractProcessingAttribute(classStr(testUIBuilder))]
   public class testContract implements SysOperationValidatable
   {
   InvoiceId invoiceId;
   ItemId itemId;
   }
2. [
   DataMemberAttribute(‘InvoiceId’),
   SysOperationDisplayOrderAttribute(‘1’)
   ]
   public InvoiceId parmInvoiceId(InvoiceId _invoiceId = invoiceId)
   {
   invoiceId = _invoiceId;
   return invoiceId;
   }
3. [
   DataMemberAttribute(‘ItemId’),
   SysOperationDisplayOrderAttribute(‘2’)
   ]
   public ItemId parmItemId(ItemId _itemId = itemId)
   {
   itemId = _itemId;
   return itemId;
   }