The OData V4 model sends requests in the following cases:

• Implicit read requests to retrieve data for a binding

  Example: A list binding with the absolute path /SalesOrderList initiates a GET SalesOrderList to read data.

• Implicit update requests via two-way binding

  Example: Update a sales order's note through a property binding with the relative path Note, which has a context with path /SalesOrderList(SalesOrderID='42') initiating PATCH SalesOrderList(SalesOrderID='42') with the note's value as JSON payload.

• Explicit requests initiated through API calls like ODataListBinding.refresh or ODataContextBinding.invoke

A group ID has one of the following submit modes to control the use of batch requests:

• sap.ui.model.odata.v4.SubmitMode.API - Requests associated with the group ID are sent in a batch request via sap.ui.model.odata.v4.ODataModel#submitBatch .

• sap.ui.model.odata.v4.SubmitMode.Auto - Requests associated with the group ID are sent in a batch request which is initiated automatically before rendering.

• sap.ui.model.odata.v4.SubmitMode.Direct - Requests associated with the group ID are sent directly without batch. Note that some features of the OData V4 model rely on the correct order of request processing in the back end. This is only guaranteed for requests made in batch requests.

The following group IDs are possible:

• "$auto" and "$auto.*": Predefined batch group ID which is the default if no group ID is specified. You can use different $auto.* group IDs to use different batch requests. The suffix can be any non-empty string consisting of alphanumeric characters from the basic Latin alphabet, including the underscore. They have the submit mode sap.ui.model.odata.v4.SubmitMode.Auto.

• "$direct": Predefined batch group ID which has the submit mode sap.ui.model.odata.v4.SubmitMode.Direct. For more information, see Performance Aspects.

• An application group ID is a non-empty string consisting of alphanumeric characters from the basic Latin alphabet, including the underscore. By default, an application group has the submit mode sap.ui.model.odata.v4.SubmitMode.API. It is possible to use a different submit mode; for details see section Define submit mode for an application group ID.

• With sap.ui.model.odata.v4.Context#delete, sap.ui.model.odata.v4.ODataModel#delete, and sap.ui.model.odata.v4.ODataContextBinding#invoke, you can also use the $single group ID. With this group ID, a single batch request is sent directly, similar to sap.ui.model.odata.v4.SubmitMode.Direct groups.

To specify the group ID for implicit requests, use the parameters $$groupId (group ID for read requests) and $$updateGroupId (group ID for update requests) for the binding which initiates the request (see the ODataModel.bindList, ODataModel.bindContext and ODataModel.bindProperty API documentation).

Batch requests for update groups with a submit mode different from $direct are queued per group ID. A batch request with changes is only sent if the previous batch request for the same group ID is returned and processed. In this case, all submitted changes for that group ID are combined in one batch request; changes associated with different calls to ODataModel.submitBatch use different change sets inside the batch request.

Code example: Updates for the sales order note through two-way binding will use the group ID "myGroup", whereas data is read with the group "$auto".

Batch group usage for binding created via JavaScript:

sap.ui.define(["sap/ui/model/odata/v4/ODataModel"], function (ODataModel) {
    var oModel = new ODataModel({serviceUrl : "/myService/", synchronizationMode : "None"}),
        oContextBinding = oModel.bindContext("/SalesOrderList(SalesOrderID='42')", /*oContext*/ undefined, {$$updateGroupId : "myGroup"}), 
        oPropertyBinding = oModel.bindProperty("Note", oContextBinding.getBoundContext());
});  

XML view sample: Declares controls which create the context binding (in the SimpleForm) and the property binding (in the Input) as sketched in the above JavaScript code sample.

Batch group usage for bindings created via XML view:

<form:SimpleForm binding="{path : '/SalesOrderList(SalesOrderID=\'42\')', parameters : {$$updateGroupId : 'myGroup'}}" editable="true" ...>
    <Label labelFor="Note" text="Note" /> 
    <Input id="Note" value="{Note}" />
    ...
</form:SimpleForm> 

On instantiation of an OData V4 model, you can provide both a group ID and an update group ID; they are used as defaults if the corresponding binding parameter is not specified. The default for the group ID is "$auto". The value of group ID is used as a default for the update group ID.

For explicit requests, the group ID can be specified as an optional parameter to the corresponding API method. The group ID or update group ID of the binding is used as a default. For more information, see the ODataContextBinding.invoke, ODataContextBinding.refresh, ODataListBinding.refresh, ODataPropertyBinding.refresh and ODataPropertyBinding.setValue API documentation in the Demo Kit.

<Toolbar design="Transparent">
    <content>
        <Button icon="sap-icon://save" press="onSaveSalesOrder"/>
        <Button icon="sap-icon://sys-cancel-2" press="onCancelSalesOrder"/>
    </content>
</Toolbar>
<form:SimpleForm id="mySimpleForm" binding="{path: '/SalesOrderList(ID=\'42\')', $$updateGroupId: 'SalesOrderUpdateGroup'}">
    <Label text="Sales Order ID" />
    <Text text="{SalesOrderID}" />
    <Label labelFor="Note" text="Note" />
    <Input id="Note" value="{Note}" />
</form:SimpleForm>

onCancelSalesOrder : function (oEvent) {
    this.getView().getModel().resetChanges("SalesOrderUpdateGroup");
},
 
onSaveSalesOrder : function (oEvent) {
    var that = this;
    this.getView().getModel().submitBatch("SalesOrderUpdateGroup").then(function(){
        if (!that.byId("mySimpleForm").getBindingContext().getBinding().hasPendingChanges()){
            // raise success message
        }
    });
},

"models" : {
    "" : {
        "dataSource" : "default",
        "settings" : {
            "operationMode" : "Server",
            "synchronizationMode" : "None",
            "groupProperties" : {
                "fastGroup" : {"submit" : "Auto"},
                "slowGroup" : {"submit" : "Auto"}
            }
        }
    }