Class ComponentRenderer<COMPONENT extends Component,​SOURCE>

Constructor Detail

• ComponentRenderer

  public ComponentRenderer​(SerializableSupplier<COMPONENT> componentSupplier,
                           SerializableBiConsumer<COMPONENT,​SOURCE> itemConsumer)

  Creates a new ComponentRenderer that uses the componentSupplier to generate new Component instances, and the itemConsumer to set the related items.

  Some components may support several rendered components at once, so different component instances should be created for each different item for those components.

  Parameters:

  componentSupplier - a supplier that can generate new component instances

  itemConsumer - a setter for the corresponding item for the rendered component

• ComponentRenderer

  public ComponentRenderer​(SerializableSupplier<COMPONENT> componentSupplier)

  Creates a new ComponentRenderer that uses the componentSupplier to generate new Component instances.

  This constructor is a convenient way of providing components to a template when the actual model item doesn't matter for the component instance.

  Some components may support several rendered components at once, so different component instances should be created for each different item for those components.

  Parameters:

  componentSupplier - a supplier that can generate new component instances

• ComponentRenderer

  public ComponentRenderer​(SerializableFunction<SOURCE,​COMPONENT> componentFunction)

  Creates a new ComponentRenderer that uses the componentFunction to generate new Component instances. The function takes a model item and outputs a component instance.

  Some components may support several rendered components at once, so different component instances should be created for each different item for those components.

  Parameters:

  componentFunction - a function that can generate new component instances

  See Also:

  ComponentRenderer(SerializableFunction, SerializableBiFunction)

• ComponentRenderer

  public ComponentRenderer​(SerializableFunction<SOURCE,​COMPONENT> componentFunction,
                           SerializableBiFunction<Component,​SOURCE,​Component> componentUpdateFunction)

  Creates a new ComponentRenderer that uses the componentFunction to generate new Component instances, and a componentUpdateFunction to update existing Component instances.

  The componentUpdateFunction can return a different component than the one previously created. In those cases, the new instance is used, and the old is discarded.

  Some components may support several rendered components at once, so different component instances should be created for each different item for those components.

  Parameters:

  componentFunction - a function that can generate new component instances

  componentUpdateFunction - a function that can update the existing component instance for the item, or generate a new component based on the item update. When the function is null, the componentFunction is always used instead

• ComponentRenderer

  protected ComponentRenderer()

  Default constructor, that can be used by subclasses which supports different ways of creating components, other than those defined in the other constructors.

Method Detail

• render

  public Rendering<SOURCE> render​(Element container,
                                  DataKeyMapper<SOURCE> keyMapper,
                                  Element contentTemplate)

  Description copied from class: Renderer

  Handles the rendering of the model objects by using the given <template> element in the given container.

  Subclasses of Renderer usually override this method to provide additional features.

  Overrides:

  render in class Renderer<SOURCE>

  Parameters:

  container - the element in which the template will be attached to, not null

  keyMapper - mapper used internally to fetch items by key and to provide keys for given items. It is required when either event handlers or DataGenerator are supported

  contentTemplate - the <template> element to be used for rendering in the container, not null

  Returns:

  the context of the rendering, that can be used by the components to provide extra customization

• setComponentRendererTag

  public void setComponentRendererTag​(String componentRendererTag)

  Sets the tag of the webcomponent used at the client-side to manage component rendering inside <template>. By default it uses <flow-component-renderer>.

  Parameters:

  componentRendererTag - the tag of the client-side webcomponent for component rendering, not null

• createComponent

  public COMPONENT createComponent​(SOURCE item)

  Creates a component for a given object model item. Subclasses can override this method to provide specific behavior.

  Parameters:

  item - the model item, possibly null

  Returns:

  a component instance representing the provided item

• updateComponent

  public Component updateComponent​(Component currentComponent,
                                   SOURCE item)

  Called when the item is updated. By default, a new Component is created (via createComponent(Object)) when the item is updated, but setting a update function via the ComponentRenderer(SerializableFunction, SerializableBiFunction) can change the behavior.

  Parameters:

  currentComponent - the current component used to render the item, not null

  item - the updated item

  Returns:

  the component that should be used to render the updated item. The same instance can be returned, or a totally new one, but not null.