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

Class TreeDataProvider<T>

java.lang.Object

com.vaadin.flow.data.provider.AbstractDataProvider<T,F>

com.vaadin.flow.data.provider.hierarchy.AbstractHierarchicalDataProvider<T,SerializablePredicate<T>>

com.vaadin.flow.data.provider.hierarchy.TreeDataProvider<T>

Type Parameters:

T - data type

All Implemented Interfaces:

ConfigurableFilterDataProvider<T,SerializablePredicate<T>,SerializablePredicate<T>>, DataProvider<T,SerializablePredicate<T>>, HierarchicalDataProvider<T,SerializablePredicate<T>>, InMemoryDataProvider<T>, Serializable

public class TreeDataProvider<T>
extends AbstractHierarchicalDataProvider<T,SerializablePredicate<T>>
implements InMemoryDataProvider<T>

An in-memory data provider for listing components that display hierarchical data. Uses an instance of TreeData as its source of data.

Since:

1.2

Author:

Vaadin Ltd

See Also:

• Serialized Form

Nested Class Summary

Nested classes/interfaces inherited from interface com.vaadin.flow.data.provider.hierarchy.HierarchicalDataProvider

HierarchicalDataProvider.HierarchyFormat

Constructor Summary

Constructors

Constructor	Description
TreeDataProvider(TreeData<T> treeData)	Constructs a new TreeDataProvider.
TreeDataProvider(TreeData<T> treeData, HierarchicalDataProvider.HierarchyFormat hierarchyFormat)	Creates a new TreeDataProvider and configures it to return the hierarchical data in the specified format: HierarchicalDataProvider.HierarchyFormat.NESTED or HierarchicalDataProvider.HierarchyFormat.FLATTENED.

Method Summary

Modifier and Type	Method	Description
Stream<T>	fetchChildren(HierarchicalQuery<T,SerializablePredicate<T>> query)	Fetches children based on the given hierarchical query.
int	getChildCount(HierarchicalQuery<T,SerializablePredicate<T>> query)	Gets the number of children based on the given hierarchical query.
int	getDepth(T item)	Gets the depth of a given item in the hierarchy, starting from zero (root).
SerializablePredicate<T>	getFilter()	Gets the current filter of this data provider.
HierarchicalDataProvider.HierarchyFormat	getHierarchyFormat()	Specifies the format in which the data provider returns hierarchical data.
SerializableComparator<T>	getSortComparator()	Gets the current sort comparator of this data provider.
TreeData<T>	getTreeData()	Return the underlying hierarchical data of this provider.
boolean	hasChildren(T item)	Check whether a given item has any children associated with it.
void	setFilter(SerializablePredicate<T> filter)	Sets a filter to be applied to all queries.
void	setSortComparator(SerializableComparator<T> comparator)	Sets the comparator to use as the default sorting for this data provider.

Methods inherited from class com.vaadin.flow.data.provider.hierarchy.AbstractHierarchicalDataProvider

refreshItem, withConfigurableFilter, withConfigurableFilter, withConvertedFilter

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

addDataProviderListener, addListener, fireEvent, refreshAll, refreshItem

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Methods inherited from interface com.vaadin.flow.data.provider.DataProvider

addDataProviderListener, getId, refreshAll, refreshItem, refreshItem

Methods inherited from interface com.vaadin.flow.data.provider.hierarchy.HierarchicalDataProvider

fetch, size

Methods inherited from interface com.vaadin.flow.data.provider.InMemoryDataProvider

addFilter, addFilter, addFilterByValue, addSortComparator, addSortOrder, clearFilters, filteringBy, filteringBy, filteringByEquals, filteringByPrefix, filteringByPrefix, filteringBySubstring, filteringBySubstring, isInMemory, setFilter, setFilterByValue, setSortOrder

Constructor Details

TreeDataProvider

public TreeDataProvider(TreeData<T> treeData)

Constructs a new TreeDataProvider.

The data provider should be refreshed after making changes to the underlying TreeData instance.

Parameters:

treeData - the backing TreeData for this provider, not null

TreeDataProvider

public TreeDataProvider(TreeData<T> treeData,
 HierarchicalDataProvider.HierarchyFormat hierarchyFormat)

Creates a new TreeDataProvider and configures it to return the hierarchical data in the specified format: HierarchicalDataProvider.HierarchyFormat.NESTED or HierarchicalDataProvider.HierarchyFormat.FLATTENED.

The data provider should be refreshed after making changes to the underlying TreeData instance.

Parameters:

treeData - the backing TreeData for this provider, not null

hierarchyFormat - the hierarchy format to return data in, not null

Method Details

getHierarchyFormat

public HierarchicalDataProvider.HierarchyFormat getHierarchyFormat()

Description copied from interface: HierarchicalDataProvider

Specifies the format in which the data provider returns hierarchical data. The default format is HierarchicalDataProvider.HierarchyFormat.NESTED.

The component uses this method to determine how to fetch and render hierarchical data with this data provider.

Specified by:

getHierarchyFormat in interface HierarchicalDataProvider<T,SerializablePredicate<T>>

Returns:

the hierarchy format

getTreeData

public TreeData<T> getTreeData()

Return the underlying hierarchical data of this provider.

Returns:

the underlying data of this provider

hasChildren

public boolean hasChildren(T item)

Description copied from interface: HierarchicalDataProvider

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

Specified by:

hasChildren in interface HierarchicalDataProvider<T,SerializablePredicate<T>>

Parameters:

item - the item to check for children

Returns:

whether the given item has children

getDepth

public int getDepth(T item)

Description copied from interface: HierarchicalDataProvider

Gets the depth of a given item in the hierarchy, starting from zero (root).

This method must be implemented for data providers that implement the flattened hierarchy format, see HierarchicalDataProvider.getHierarchyFormat() and HierarchicalDataProvider.HierarchyFormat.FLATTENED.

Specified by:

getDepth in interface HierarchicalDataProvider<T,SerializablePredicate<T>>

Parameters:

item - the item to get the depth for

Returns:

the depth of the item in the hierarchy

getChildCount

public int getChildCount(HierarchicalQuery<T,SerializablePredicate<T>> query)

Description copied from interface: HierarchicalDataProvider

Gets the number of children based on the given hierarchical query.

This method must be implemented in accordance with the selected hierarchy type, see HierarchicalDataProvider.getHierarchyFormat() and HierarchicalDataProvider.HierarchyFormat.

Specified by:

getChildCount in interface HierarchicalDataProvider<T,SerializablePredicate<T>>

Parameters:

query - given query to request the count for

Returns:

the count of children for the parent item or the root level if the parent is null

fetchChildren

public Stream<T> fetchChildren(HierarchicalQuery<T,SerializablePredicate<T>> query)

Description copied from interface: HierarchicalDataProvider

Fetches children based on the given hierarchical query.

This method must be implemented in accordance with the selected hierarchy type, see HierarchicalDataProvider.getHierarchyFormat() and HierarchicalDataProvider.HierarchyFormat.

Specified by:

fetchChildren in interface HierarchicalDataProvider<T,SerializablePredicate<T>>

Parameters:

query - given query to request data with

Returns:

a stream of data objects for the parent item or the root level if the parent is null, must not contain null values

getFilter

public SerializablePredicate<T> getFilter()

Description copied from interface: InMemoryDataProvider

Gets the current filter of this data provider.

Specified by:

getFilter in interface InMemoryDataProvider<T>

Returns:

the filter of this data provider

setFilter

public void setFilter(SerializablePredicate<T> filter)

Description copied from interface: InMemoryDataProvider

Sets a filter to be applied to all queries. The filter replaces any filter that has been set or added previously.

Specified by:

setFilter in interface ConfigurableFilterDataProvider<T,SerializablePredicate<T>,SerializablePredicate<T>>

Specified by:

setFilter in interface InMemoryDataProvider<T>

Parameters:

filter - the filter to set, or null to remove any set filters

See Also:

• InMemoryDataProvider.setFilter(ValueProvider, SerializablePredicate)
• InMemoryDataProvider.setFilterByValue(ValueProvider, Object)
• InMemoryDataProvider.addFilter(SerializablePredicate)

getSortComparator

public SerializableComparator<T> getSortComparator()

Description copied from interface: InMemoryDataProvider

Gets the current sort comparator of this data provider.

Specified by:

getSortComparator in interface InMemoryDataProvider<T>

Returns:

the sort comparator of this data provider

setSortComparator

public void setSortComparator(SerializableComparator<T> comparator)

Description copied from interface: InMemoryDataProvider

Sets the comparator to use as the default sorting for this data provider. This overrides the sorting set by any other method that manipulates the default sorting of this data provider.

The default sorting is used if the query defines no sorting. The default sorting is also used to determine the ordering of items that are considered equal by the sorting defined in the query.

Specified by:

setSortComparator in interface InMemoryDataProvider<T>

Parameters:

comparator - a comparator to use, or null to clear any previously set sort order

See Also:

• InMemoryDataProvider.setSortOrder(ValueProvider, SortDirection)
• InMemoryDataProvider.addSortComparator(SerializableComparator)