Sapui5 how can refresh batch requests before submit changes

[junwu]

var oModel = this.getView().getModel();
oModel.setDeferredGroups(["maraGroupId"]);
oModel.setUseBatch(true);


var mParameters = {
"groupId": "maraGroupId",
"changeSetId": "maraChangeSetId"
};

var oEntry = {};
oEntry.Matnr = "1";
oModel.create("/MaraSet", oEntry, mParameters);

oEntry.Matnr = "2";
oModel.create("/MaraSet", oEntry, mParameters);

oEntry.Matnr = "3";
oModel.create("/MaraSet", oEntry, mParameters);

oModel.submitChanges(mParameters);

[junwu]

check the data before calling create

[junwu]

one loop to check data, if it goes well, then another loop to call create

[junwu]

low performance?? how low it will be? don't just imagine.......