3.9.4.2. Viewing the Entity Log

The entity log content can be viewed on a dedicated screen available at Administration > Entity Log.

The change log for a certain entity can also be accessed from any application screen by loading a collection of EntityLogItem and the associated EntityLogAttr instances into the data containers and creating the visual components connected to these containers.

The example below shows the fragment of the screen XML descriptor of a Customer entity which has a tab with the entity log content.

The fragment of the customer-edit.xml 
<data>
    <instance id="customerDc"
              class="com.company.sample.entity.Customer"
              view="customer-view">
        <loader id="customerDl"/>
    </instance>
    <collection id="entitylogsDc"
                class="com.haulmont.cuba.security.entity.EntityLogItem"
                view="logView" >
        <loader id="entityLogItemsDl">
            <query><![CDATA[select i from sec$EntityLog i where i.entityRef.entityId = :customer
                            order by i.eventTs]]>
            </query>
        </loader>
        <collection id="logAttrDc"
                    property="attributes"/>
    </collection>
</data>
<layout>
    <tabSheet id="tabSheet">
        <tab id="propertyTab">
            <!--...-->
        </tab>
        <tab id="logTab">
            <table id="logTable"
                   dataContainer="entitylogsDc"
                   width="100%"
                   height="100%">
                <columns>
                    <column id="eventTs"/>
                    <column id="user.login"/>
                    <column id="type"/>
                </columns>
            </table>
            <table id="attrTable"
                   height="100%"
                   width="100%"
                   dataContainer="logAttrDc">
                <columns>
                    <column id="name"/>
                    <column id="oldValue"/>
                    <column id="value"/>
                </columns>
            </table>
        </tab>
    </tabSheet>
</layout>

Let us have a look on the Customer screen controller:

The fragment of the Customer screen controller 
@UiController("sample_Customer.edit")
@UiDescriptor("customer-edit.xml")
@EditedEntityContainer("customerDc")
public class CustomerEdit extends StandardEditor<Customer> {
    @Inject
    private InstanceLoader<Customer> customerDl;
    @Inject
    private CollectionLoader<EntityLogItem> entityLogItemsDl;

    @Subscribe
    private void onBeforeShow(BeforeShowEvent event) { (1)
        customerDl.load();
    }

    @Subscribe(id = "customerDc", target = Target.DATA_CONTAINER)
    private void onCustomerDcItemChange(InstanceContainer.ItemChangeEvent<Customer> event) { (2)
        entityLogItemsDl.setParameter("customer", event.getItem().getId());
        entityLogItemsDl.load();
    }
}

Notice that the screen has no @LoadDataBeforeShow annotation, because loading is triggered explicitly.

1 − the onBeforeShow method loads data before showing the screen.
2 − in the ItemChangeEvent handler of the customerDc container, a parameter is set to the dependent loader and it is triggered.