Method Details

• size

  default int size(Query<T,F> query)

  Get the number of immediate child data items for the parent item returned by a given query.

  Specified by:

  size in interface DataProvider<T,F>

  Parameters:

  query - given query to request the count for

  Returns:

  the count of child data items for the data item HierarchicalQuery.getParent()

  Throws:

  IllegalArgumentException - if the query is not of type HierarchicalQuery

• fetch

  default Stream<T> fetch(Query<T,F> query)

  Fetches data from this HierarchicalDataProvider using given query. Only the immediate children of HierarchicalQuery.getParent() will be returned.

  Specified by:

  fetch in interface DataProvider<T,F>

  Parameters:

  query - given query to request data with

  Returns:

  a stream of data objects resulting from the query

  Throws:

  IllegalArgumentException - if the query is not of type HierarchicalQuery

• getChildCount

  int getChildCount(HierarchicalQuery<T,F> query)

  Get the number of immediate child data items for the parent item returned by a given query.

  Parameters:

  query - given query to request the count for

  Returns:

  the count of child data items for the data item HierarchicalQuery.getParent()

• fetchChildren

  Stream<T> fetchChildren(HierarchicalQuery<T,F> query)

  Fetches data from this HierarchicalDataProvider using given query. Only the immediate children of HierarchicalQuery.getParent() will be returned.

  Parameters:

  query - given query to request data with

  Returns:

  a stream of data objects resulting from the query

• hasChildren

  boolean hasChildren(T item)

  Check whether a given item has any children associated with it.

  Parameters:

  item - the item to check for children

  Returns:

  whether the given item has children

• withConfigurableFilter

  default <Q, C> HierarchicalConfigurableFilterDataProvider<T,Q,C> withConfigurableFilter(SerializableBiFunction<Q,C,F> filterCombiner)

  Description copied from interface: DataProvider

  Wraps this data provider to create a data provider that supports programmatically setting a filter that will be combined with a filter provided through the query.

  Specified by:

  withConfigurableFilter in interface DataProvider<T,F>

  Type Parameters:

  Q - the query filter type

  C - the configurable filter type

  Parameters:

  filterCombiner - a callback for combining and the configured filter with the filter from the query to get a filter to pass to the wrapped provider. Either parameter might be null, but the callback will not be invoked at all if both would be null. Not null.

  Returns:

  a data provider with a configurable filter, not null

  See Also:

  • DataProvider.withConfigurableFilter()
  • ConfigurableFilterDataProvider.setFilter(Object)

• withConvertedFilter

  default <C> HierarchicalDataProvider<T,C> withConvertedFilter(SerializableFunction<C,F> filterConverter)

  Description copied from interface: DataProvider

  Wraps this data provider to create a data provider that uses a different filter type. This can be used for adapting this data provider to a filter type provided by a Component such as ComboBox.

  For example receiving a String from ComboBox and making a Predicate based on it:

   DataProvider<Person, Predicate<Person>> dataProvider;
   // ComboBox uses String as the filter type
   DataProvider<Person, String> wrappedProvider = dataProvider
           .withConvertedFilter(filterText -> {
               Predicate<Person> predicate = person -> person.getName()
                       .startsWith(filterText);
               return predicate;
           });
   comboBox.setDataProvider(wrappedProvider);
   

  Specified by:

  withConvertedFilter in interface DataProvider<T,F>

  Type Parameters:

  C - the filter type that the wrapped data provider accepts; typically provided by a Component

  Parameters:

  filterConverter - callback that converts the filter in the query of the wrapped data provider into a filter supported by this data provider. Will only be called if the query contains a filter. Not null

  Returns:

  wrapped data provider, not null

• withConfigurableFilter

  default HierarchicalConfigurableFilterDataProvider<T,Void,F> withConfigurableFilter()

  Description copied from interface: DataProvider

  Wraps this data provider to create a data provider that supports programmatically setting a filter but no filtering through the query.

  Specified by:

  withConfigurableFilter in interface DataProvider<T,F>

  Returns:

  a data provider with a configurable filter, not null

  See Also:

  • DataProvider.withConfigurableFilter(SerializableBiFunction)
  • ConfigurableFilterDataProvider.setFilter(Object)