com.vaadin.flow.data.provider.hierarchy.

java.lang.Object
- com.vaadin.flow.data.provider.DataCommunicator<T>
- - com.vaadin.flow.data.provider.hierarchy.HierarchicalDataCommunicator<T>

Type Parameters:

T - the bean type

All Implemented Interfaces:

Serializable
```
public class HierarchicalDataCommunicator<T>
extends DataCommunicator<T>
```
Data communicator that handles requesting hierarchical data from HierarchicalDataProvider and sending it to client side.

Since:

1.2

Author:

Vaadin Ltd

See Also:

Serialized Form

Nested Class Summary
- Nested classes/interfaces inherited from class com.vaadin.flow.data.provider.DataCommunicator
  DataCommunicator.EmptyDataProvider<T1>, DataCommunicator.Filter<F>

Field Summary
- Fields inherited from class com.vaadin.flow.data.provider.DataCommunicator
  DEFAULT_PAGE_INCREASE_COUNT

Constructor Summary

Constructors
Constructor	Description
`HierarchicalDataCommunicator(CompositeDataGenerator<T> dataGenerator, HierarchicalArrayUpdater arrayUpdater, SerializableConsumer<elemental.json.JsonArray> dataUpdater, StateNode stateNode, SerializableSupplier<ValueProvider<T,String>> uniqueKeyProviderSupplier)`	Construct a new hierarchical data communicator backed by a `TreeDataProvider`.

Method Summary

All Methods
Modifier and Type	Method	Description
`Collection<T>`	`collapse(Collection<T> items)`	Collapses the given items and removes its sub-hierarchy.
`void`	`collapse(T item)`	Collapses the given item and removes its sub-hierarchy.
`protected void`	`collapse(T item, boolean syncClient)`	Collapses the given item and removes its sub-hierarchy.
`void`	`confirmUpdate(int id, String parentKey)`
`protected <F> HierarchyMapper<T,F>`	`createHierarchyMapper(HierarchicalDataProvider<T,F> dataProvider)`	Create new `HierarchyMapper` for the given data provider.
`Collection<T>`	`expand(Collection<T> items)`	Expands the given items.
`void`	`expand(T item)`	Expands the given item.
`protected void`	`expand(T item, boolean syncClient)`	Expands the given item.
`Stream<T>`	`fetchFromProvider(int offset, int limit)`	Fetches a list of items from the DataProvider.
`HierarchicalDataProvider<T,?>`	`getDataProvider()`	Gets the current data provider from this DataCommunicator.
`int`	`getDataProviderSize()`	Getter method for determining the item count of the data.
`int`	`getDepth(T item)`	Returns depth of item in the tree starting from zero representing a root.
`protected HierarchyMapper<T,?>`	`getHierarchyMapper()`	Returns the `HierarchyMapper` used by this data communicator.
`Integer`	`getIndex(T item)`	Returns index for the row or `null`.
`Integer`	`getParentIndex(T item)`	Returns parent index for the row or `null`.
`T`	`getParentItem(T item)`	Returns parent item for the row or `null`.
`protected void`	`handleDataRefreshEvent(DataChangeEvent.DataRefreshEvent<T> event)`
`boolean`	`hasChildren(T item)`	Returns whether given item has children.
`boolean`	`hasExpandedItems()`	Returns true if there is any expanded items.
`boolean`	`isExpanded(T item)`	Returns whether given item is expanded.
`void`	`reset()`	Resets all the data.
`void`	`setBackEndSorting(List<QuerySortOrder> sortOrder)`	Sets the `QuerySortOrder`s to use with backend sorting.
`<F> SerializableConsumer<F>`	`setDataProvider(DataProvider<T,F> dataProvider, F initialFilter)`	Set the current hierarchical data provider for this communicator.
`<F> SerializableConsumer<F>`	`setDataProvider(HierarchicalDataProvider<T,F> dataProvider, F initialFilter)`	Set the current hierarchical data provider for this communicator.
`protected <F> void`	`setFilter(F filter)`
`void`	`setInMemorySorting(SerializableComparator<T> comparator)`	Sets the `Comparator` to use with in-memory sorting.
`void`	`setParentRequestedRange(int start, int length, T parentItem)`

Methods inherited from class com.vaadin.flow.data.provider.DataCommunicator
buildQuery, confirmUpdate, enablePushUpdates, getBackEndSorting, getFilter, getInMemorySorting, getItem, getItemCount, getItemCountEstimate, getItemCountEstimateIncrease, getKeyMapper, getPageSize, isDefinedSize, isFetchEnabled, isItemActive, isPagingEnabled, refresh, setCountCallback, setDataProvider, setDefinedSize, setFetchEnabled, setItemCountEstimate, setItemCountEstimateIncrease, setKeyMapper, setPageSize, setPagingEnabled, setRequestedRange

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Constructor Detail
  - HierarchicalDataCommunicator
```
public HierarchicalDataCommunicator(CompositeDataGenerator<T> dataGenerator,
                                    HierarchicalArrayUpdater arrayUpdater,
                                    SerializableConsumer<elemental.json.JsonArray> dataUpdater,
                                    StateNode stateNode,
                                    SerializableSupplier<ValueProvider<T,String>> uniqueKeyProviderSupplier)
```
    Construct a new hierarchical data communicator backed by a TreeDataProvider.
    
    Parameters:
    
    dataGenerator - the data generator function
    
    arrayUpdater - array updater strategy
    
    dataUpdater - data updater strategy
    
    stateNode - the state node used to communicate for
    
    uniqueKeyProviderSupplier - Unique key provider for a row. If null, then using Grid's default key generator.
- Method Detail
  - reset
```
public void reset()
```
    Resets all the data.
    It effectively resends all available data.
    
    Overrides:
    
    reset in class DataCommunicator<T>
  - handleDataRefreshEvent
```
protected void handleDataRefreshEvent(DataChangeEvent.DataRefreshEvent<T> event)
```
    Overrides:
    
    handleDataRefreshEvent in class DataCommunicator<T>
  - fetchFromProvider
```
public Stream<T> fetchFromProvider(int offset,
                                   int limit)
```
    Description copied from class: DataCommunicator
    
    Fetches a list of items from the DataProvider.
    NOTE: the limit parameter shows how many items the client wants to fetch, but the actual number of results may be greater, and vary from 0 to pages * pageSize.
    
    Overrides:
    
    fetchFromProvider in class DataCommunicator<T>
    
    Parameters:
    
    offset - the starting index of the range
    
    limit - the desired number of results
    
    Returns:
    
    the list of items in given range
  - setParentRequestedRange
```
public void setParentRequestedRange(int start,
                                    int length,
                                    T parentItem)
```
  - getDataProvider
```
public HierarchicalDataProvider<T,?> getDataProvider()
```
    Description copied from class: DataCommunicator
    
    Gets the current data provider from this DataCommunicator.
    
    Overrides:
    
    getDataProvider in class DataCommunicator<T>
    
    Returns:
    
    the data provider
  - setDataProvider
```
public <F> SerializableConsumer<F> setDataProvider(HierarchicalDataProvider<T,F> dataProvider,
                                                   F initialFilter)
```
    Set the current hierarchical data provider for this communicator.
    
    Type Parameters:
    
    F - the filter type
    
    Parameters:
    
    dataProvider - the data provider to set, not null
    
    initialFilter - the initial filter value to use, or null to not use any initial filter value
    
    Returns:
    
    a consumer that accepts a new filter value to use
  - createHierarchyMapper
```
protected <F> HierarchyMapper<T,F> createHierarchyMapper(HierarchicalDataProvider<T,F> dataProvider)
```
    Create new HierarchyMapper for the given data provider. May be overridden in subclasses.
    
    Type Parameters:
    
    F - Query type
    
    Parameters:
    
    dataProvider - the data provider
    
    Returns:
    
    new HierarchyMapper
  - setDataProvider
```
public <F> SerializableConsumer<F> setDataProvider(DataProvider<T,F> dataProvider,
                                                   F initialFilter)
```
    Set the current hierarchical data provider for this communicator.
    
    Overrides:
    
    setDataProvider in class DataCommunicator<T>
    
    Type Parameters:
    
    F - the filter type
    
    Parameters:
    
    dataProvider - the data provider to set, must extend HierarchicalDataProvider, not null
    
    initialFilter - the initial filter value to use, or null to not use any initial filter value
    
    Returns:
    
    a consumer that accepts a new filter value to use
  - confirmUpdate
```
public void confirmUpdate(int id,
                          String parentKey)
```
  - collapse
```
public void collapse(T item)
```
    Collapses the given item and removes its sub-hierarchy. Calling this method will have no effect if the row is already collapsed.
    Changes are synchronized to the client.
    
    Parameters:
    
    item - the item to collapse
  - collapse
```
protected void collapse(T item,
                        boolean syncClient)
```
    Collapses the given item and removes its sub-hierarchy. Calling this method will have no effect if the row is already collapsed. syncClient indicates whether the changes should be synchronized to the client.
    
    Parameters:
    
    item - the item to collapse
    
    syncClient - true if the changes should be synchronized to the client, false otherwise.
  - collapse
```
public Collection<T> collapse(Collection<T> items)
```
    Collapses the given items and removes its sub-hierarchy. Calling this method will have no effect if the row is already collapsed.
    Changes are synchronized to the client.
    
    Parameters:
    
    items - the items to collapse
    
    Returns:
    
    the collapsed items
  - expand
```
public void expand(T item)
```
    Expands the given item. Calling this method will have no effect if the item is already expanded or if it has no children.
    Changes are synchronized to the client.
    
    Parameters:
    
    item - the item to expand
  - expand
```
public Collection<T> expand(Collection<T> items)
```
    Expands the given items. Calling this method will have no effect if the item is already expanded or if it has no children.
    Changes are synchronized to the client.
    
    Parameters:
    
    items - the items to expand
    
    Returns:
    
    the expanded items
  - expand
```
protected void expand(T item,
                      boolean syncClient)
```
    Expands the given item. Calling this method will have no effect if the item is already expanded or if it has no children. syncClient indicates whether the changes should be synchronized to the client.
    
    Parameters:
    
    item - the item to expand
    
    syncClient - true if the changes should be synchronized to the client, false otherwise.
  - hasChildren
```
public boolean hasChildren(T item)
```
    Returns whether given item has children.
    
    Parameters:
    
    item - the item to test
    
    Returns:
    
    true if item has children; false if not
  - isExpanded
```
public boolean isExpanded(T item)
```
    Returns whether given item is expanded.
    
    Parameters:
    
    item - the item to test
    
    Returns:
    
    true if item is expanded; false if not
  - getParentIndex
```
public Integer getParentIndex(T item)
```
    Returns parent index for the row or null.
    
    Parameters:
    
    item - the item to find the parent of
    
    Returns:
    
    the parent index or null for top-level items
  - getIndex
```
public Integer getIndex(T item)
```
    Returns index for the row or null.
    
    Parameters:
    
    item - the target item
    
    Returns:
    
    the index or null for top-level and non-existing items
  - getParentItem
```
public T getParentItem(T item)
```
    Returns parent item for the row or null.
    
    Parameters:
    
    item - the item to find the parent of
    
    Returns:
    
    the parent item or null for top-level items
  - getDepth
```
public int getDepth(T item)
```
    Returns depth of item in the tree starting from zero representing a root.
    
    Parameters:
    
    item - Target item
    
    Returns:
    
    depth of item in the tree or -1 if item is null
  - getDataProviderSize
```
public int getDataProviderSize()
```
    Description copied from class: DataCommunicator
    
    Getter method for determining the item count of the data.
    This method should be used only with defined size, i.e. when DataCommunicator.isDefinedSize() returns true.
    Can be overridden by a subclass that uses a specific type of DataProvider and/or query.
    
    Overrides:
    
    getDataProviderSize in class DataCommunicator<T>
    
    Returns:
    
    the size of data provider with current filter
  - setBackEndSorting
```
public void setBackEndSorting(List<QuerySortOrder> sortOrder)
```
    Description copied from class: DataCommunicator
    
    Sets the QuerySortOrders to use with backend sorting.
    
    Overrides:
    
    setBackEndSorting in class DataCommunicator<T>
    
    Parameters:
    
    sortOrder - list of sort order information to pass to a query
  - setInMemorySorting
```
public void setInMemorySorting(SerializableComparator<T> comparator)
```
    Description copied from class: DataCommunicator
    
    Sets the Comparator to use with in-memory sorting.
    
    Overrides:
    
    setInMemorySorting in class DataCommunicator<T>
    
    Parameters:
    
    comparator - comparator used to sort data
  - setFilter
```
protected <F> void setFilter(F filter)
```
  - hasExpandedItems
```
public boolean hasExpandedItems()
```
    Returns true if there is any expanded items.
    
    Returns:
    
    true if there is any expanded items.
  - getHierarchyMapper
```
protected HierarchyMapper<T,?> getHierarchyMapper()
```
    Returns the HierarchyMapper used by this data communicator.
    
    Returns:
    
    the hierarchy mapper used by this data communicator

com.vaadin.flow.data.provider.hierarchy.

Class HierarchicalDataCommunicator<T>

Nested Class Summary

Nested classes/interfaces inherited from class com.vaadin.flow.data.provider.DataCommunicator

Field Summary

Fields inherited from class com.vaadin.flow.data.provider.DataCommunicator

Constructor Summary

Method Summary

Methods inherited from class com.vaadin.flow.data.provider.DataCommunicator

Methods inherited from class java.lang.Object

Constructor Detail

HierarchicalDataCommunicator

Method Detail

reset

handleDataRefreshEvent

fetchFromProvider

setParentRequestedRange

getDataProvider

setDataProvider

createHierarchyMapper

setDataProvider

confirmUpdate

collapse

collapse

collapse

expand

expand

expand

hasChildren

isExpanded

getParentIndex

getIndex

getParentItem

getDepth

getDataProviderSize

setBackEndSorting

setInMemorySorting

setFilter

hasExpandedItems

getHierarchyMapper