Package com.vaadin.flow.data.provider

Class AbstractDataView<T>

java.lang.Object
com.vaadin.flow.data.provider.AbstractDataView<T>
Type Parameters:
T - data type
All Implemented Interfaces:
DataView<T>, Serializable
Direct Known Subclasses:
AbstractLazyDataView, AbstractListDataView, CheckboxGroupDataView, ComboBoxDataView, GridDataView, ListBoxDataView, RadioButtonGroupDataView, SelectDataView
public abstract class AbstractDataView<T> extends Object implements DataView<T>
Abstract data view implementation which handles parts that apply for any type of data.
See Also:

  • Field Details

  • Constructor Details

    • AbstractDataView

      public AbstractDataView(SerializableSupplier<? extends DataProvider<T,?>> dataProviderSupplier, Component component)
      Creates a new instance of AbstractDataView subclass and verifies the passed data provider is compatible with this data view implementation.
      Parameters:
      dataProviderSupplier - supplier from which the DataProvider can be gotten
      component - the component that the dataView is bound to

  • Method Details

    • addItemCountChangeListener

      public Registration addItemCountChangeListener(ComponentEventListener<ItemCountChangeEvent<?>> listener)
      Description copied from interface: DataView
      Add an item count change listener that is fired when the item count changes. This can happen for instance when filtering the items.

      Item count change listener is bound to the component and will be retained even if the data changes by setting of a new items or DataProvider to component.

      NOTE: when the component supports lazy loading (implements HasLazyDataView) and a count callback has not been provided, an estimate of the item count is used and increased until the actual count has been reached. When the estimate is used, the event is fired with the ItemCountChangeEvent.isItemCountEstimated() returning true.

      Specified by:
      addItemCountChangeListener in interface DataView<T>
      Parameters:
      listener - item count change listener to register
      Returns:
      registration for removing the listener

    • getSupportedDataProviderType

      protected abstract Class<?> getSupportedDataProviderType()
      Returns supported DataProvider type for this DataView.
      Returns:
      supported data provider type

    • verifyDataProviderType

      protected final void verifyDataProviderType(Class<?> dataProviderType)
      Verifies an obtained DataProvider type is appropriate for current Data View type.
      Parameters:
      dataProviderType - data provider type to be verified
      Throws:
      IllegalStateException - if data provider type is incompatible with data view type

    • getItems

      public Stream<T> getItems()
      Description copied from interface: DataView
      Get the full data available to the component. Data is filtered and sorted the same way as in the component.
      Specified by:
      getItems in interface DataView<T>
      Returns:
      filtered and sorted data set

    • refreshItem

      public void refreshItem(T item)
      Description copied from interface: DataView
      Notifies the component that the item has been updated and thus should be refreshed.

      For this to work properly, the item must either implement Object.equals(Object) and Object.hashCode() to consider both the old and the new item instances to be equal, or alternatively use the DataView.setIdentifierProvider(IdentifierProvider) to set an appropriate item's identifier.

      This method delegates the update to DataProvider.refreshItem(Object).

      Specified by:
      refreshItem in interface DataView<T>
      Parameters:
      item - item containing updated state
      See Also:

    • refreshAll

      public void refreshAll()
      Description copied from interface: DataView
      Notifies the component that all the items should be refreshed.
      Specified by:
      refreshAll in interface DataView<T>

    • setIdentifierProvider

      public void setIdentifierProvider(IdentifierProvider<T> identifierProvider)
      Description copied from interface: DataView
      Sets an identifier provider, which returns an identifier for the given item. The identifier is used for comparing the equality of items. Usage example: dataView.setIdentifiedProvider(Item::getId);.
      Specified by:
      setIdentifierProvider in interface DataView<T>
      Parameters:
      identifierProvider - function that returns the non-null identifier for a given item

    • getIdentifierProvider

      protected IdentifierProvider<T> getIdentifierProvider()

    • addIdentifierProviderChangeListener

      public Registration addIdentifierProviderChangeListener(ComponentEventListener<IdentifierProviderChangeEvent<T,?>> listener)
      Add an identifier provider change listener that is fired when a custom identifier provider is set with setIdentifierProvider(IdentifierProvider).

      Can be used by components to get notified that a new identifier provider has been set through the data view.

      Parameters:
      listener - identifier provider change listener to register
      Returns:
      registration for removing the listener

    • equals

      protected boolean equals(T item, T compareTo)