How to return back ODataModel in SAPUI5 to its original state after using setDeferredGroups? - sapui5

Question

I have a SAPUI5 application that uses OData V2.
In one part of the application for deleting of the items in a list I have to close change set after each call.
Then I use the following code:
sGroupId = "dmsch" + new Date().getTime();
oDataModel.setDeferredGroups([sGroupId]);
for (var i = 0; i < aSelectedContexts.length; i++) {
var sObjectPath = aSelectedContexts[i].getPath();
this._deleteObject(sObjectPath, sGroupId, fnAllRequestCompleted, fnAllRequestFailed);
}
oDataModel.submitChanges({
groupId: sGroupId
});
And in the _deleteObject function I set different changeSetId for each request, the b:
_deleteObject: function(sObjectPath, sGroupId, fnSuccessCallBackFunction, fnFailedCallBackFunction) {
var oDataModel = this.getModel();
var sChangeSetId = "cs" + (new Date().getTime() * (1 + Math.random()));
oDataModel.remove(sObjectPath, {
groupId: sGroupId,
changeSetId: sChangeSetId,
......
Now after a successful delete as soon as I create a new entry by using the createEntry function it tries to send the data of that entry to the server.
The question is how can I reset the effect of setDeferredGroups function.
Note: I need to use setDeferredGroups, and I am sure it is reason of sending newly created entries automatically to the server by each change. I need to set the setting of the ODataModel back to its original state.
Note2: Here is something regarding oData Version 4 that explain this automatic behavior after a failure.

Answer 1

The SAP docs here - I've tried to summarize below.
The default change groups are
{"*": {
groupId: "changes"
}
}
And the default deferred groups are
["changes"]
You can reset the data model change groups to default using
oModel.setChangeGroups({"*": {
groupId: "changes"
}
});
oModel.setDeferredGroups(["changes"]);
With this default configuration, all changes to all entity types will be collected in the changes group, and are deferred (not sent to the server automatically).
So oModel.setChangeGroups(...) is how change groups are defined, and oModel.setDeferredGroups is how each of those groups is determined to be deferred or not
The reason I mention the default change groups AND the default deferred groups, is because if not set properly, you may see unexpected behavior when using two way data binding.
For example: removing the default change group by calling oModel.setChangeGroups({}) will result in all changes to all entity types NOT getting collected into any change group, and thus not being deferred. You will see any changes made sent to the server automatically.
So lets say you have an entity type Employee and you want any changes made to this entity type to be collected in one group and be deferred:
var oChangeGroups = oModel.getChangeGroups();
oChangeGroups.Employee = {groupId: "employees"};
oModel.setChangeGroups(oChangeGroups);
var aDeferredGroups = oModel.getDeferredGroups();
aDeferredGroups.push("employees");
oModel.setDeferredGroups(aDeferredGroups);
Now you have two change groups, * with ID changes and Employee with ID employees. Any changes made to any Employee entities will be in the employees group, and all other changes will be in the changes group.
So now any create/delete/update of an employee can be submitted separately from any other changes to other entity types
oModel.createEntry("/EmployeeSet", {
groupId: "employees",
properties: {
name: "New Guy"
}
});
oModel.submitChanges({groupId: "employees"});
From this point, to go back to the default and get rid of the employees change group, you can use what I wrote above to reset everything back to default.