Deleting_an_Entity_2613ebc.md

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Deleting an Entity

The v4.Context.delete method deletes an entity on the server and updates the user interface accordingly.

When you delete the entity from a list binding, the corresponding row is removed immediately, even if an API group is used and the request waits for the submitBatch. If the request fails, or the deletion is canceled via ODataModel#resetChanges, ODataListBinding#resetChanges, or v4.Context#resetChanges, the row is re-inserted.

Bound messages targeting the entity, one of its properties, or its navigation properties, are also removed immediately; this applies to both state and transition messages. If you cancel the deletion, these messages are restored. If the deletion fails, only the state messages are restored; the transition messages are dropped to make room for new transition messages resulting from the failed deletion.

As soon as a context is deleted on the client, #isDeleted returns true and the context must not be used anymore (except by status APIs like #isDeleted, #isKeepAlive, #hasPendingChanges, #resetChanges). If the context is used as a binding context of a control or view, be sure to unbind it using setBindingContext(null). If the context is restored due to a failure or reset, you might want to rebind this control or view again.

Once the entity is finally deleted on the server (i.e. the promise of #delete is resolved), no method of the context may be used anymore.

Example: Delete from a table with an object page

onDeleteSalesOrder : function () {
    var oTable = this.getView().byId("SalesOrders"),
        oSalesOrderContext = oTable.getSelectedItem().getBindingContext(),
        oObjectPage = this.getView().byID("objectPage");

    if (oObjectPage.getBindingContext() === oSalesOrderContext) {
        oObjectPage.setBindingContext(null);
    }
    oSalesOrderContext.delete().then(function () {
        MessageBox.alert("Deleted Sales Order",
            {icon : MessageBox.Icon.SUCCESS, title : "Success"});
    }, function (oError) {
        if (oSalesOrderContext === that.oLastSelectedSalesOrderContext) {
            oObjectPage.setBindingContext(oSalesOrderContext);
        }
        MessageBox.alert("Could not delete Sales Order: "
            + oError.message, {icon : MessageBox.Icon.ERROR, title : "Error"});
    });
},

You can also delete an entity from the model and all its bindings via v4.ODataModel#delete using a canonical binding path to the entity. The model then sends a DELETE request to the server. If this request succeeds, the entity is removed from all its bindings. The conditions for identifying these bindings are described in the API documentation.

Caution:

Be cautious if your control or view uses a binding with an empty path (<Page id="entityDetails" binding="{}">) and you want to delete the entity it displays. The context you get via oView.byId("entityDetails").getBindingContext() can be used to delete this entity, but calling delete() immediately makes the context binding unresolved and destroys the context. The same holds true if you call oView.byId("entityDetails").setBindingContext(null) to clear the control or view. This makes it impossible to restore the control or view in case of failure.

Using context bindings with an empty path is deprecated and should be avoided if possible. Consider setting up your views as described in Data Reuse. The binding context of your detail page is then the list's row context, and there will be no issue regarding data sharing or deleting.

Related Information

Context.delete