Customize link to delete view

As of 3.2.0.RELEASE the delete menu item has been removed from the advanced-options menu and a link has been added to the detail and update view. To return to the previous behaviour, please see the following steps.

Add the delete menu item

To add the delete menu item to the advanced menu, simply catch the EntityAdminMenuEvent that is published and add an item to the /advanced-options group.

@EventListener
public void customizeEntityMenu( EntityAdminMenuEvent menu ) { (1)
    PathBasedMenuBuilder builder = menu.builder();
    EntityConfiguration<Object> entityConfiguration = entityRegistry.getEntityConfiguration( menu.getEntityType() );
    EntityMessageCodeResolver messageCodeResolver = entityConfiguration.getEntityMessageCodeResolver();

    if ( menu.isForUpdate() ) { (2)
        AllowableActions allowableActions = entityConfiguration.getAllowableActions( menu.getEntity() );
        val currentEntityLink = menu.getLinkBuilder().forInstance( menu.getEntity() );

        if ( allowableActions.contains( AllowableAction.DELETE ) ) { (3)
            val deleteLink = currentEntityLink.deleteView();

            builder.item( "/advanced-options/delete", (4)
                          messageCodeResolver.getMessageWithFallback( "menu.delete", "Delete" ),
                          deleteLink.withFromUrl( ServletUriComponentsBuilder.fromCurrentRequestUri().build().getPath() ).toString() ) ) (5)
                   .attribute( RequestMenuSelector.ATTRIBUTE_MATCHERS, Collections.singleton( deleteLink.toUriString() ) )
                   .attribute( NavComponentBuilder.ATTR_ICON, new GlyphIcon( GlyphIcon.TRASH ) )
                   .attribute( NavComponentBuilder.ATTR_INSERT_SEPARATOR, NavComponentBuilder.Separator.BEFORE )
                   .order( Ordered.LOWEST_PRECEDENCE );
        }
    }
}

1	Catch all events that render the admin menu for an entity type.
2	Check whether the menu is rendered for an existing instance. This ensures that an entity is available for which the menu is rendered.
3	The link should only be added if a user has the `AllowableAction.DELETE` for the instance.
4	Provide a menu item that links to the delete view.
5	Redirect to the current view if the cancel link is clicked.

Removing the delete button from the form views

The delete button on the detail and update view is added via the DeleteActionFormViewProcessor. To remove it, simply remove the processor from the specified views.

@Override
public void configure( EntitiesConfigurationBuilder entities ) {
    entities.all() (1)
            .detailView(fvb -> fvb.removeViewProcessor( DeleteActionFormViewProcessor.class.getName() ))
            .updateFormView(fvb -> fvb.removeViewProcessor( DeleteActionFormViewProcessor.class.getName() ));
}

1	Remove the `DeleteActionFormViewProcessor` from every detail and update view.