com.vaadin.flow.data.provider.hierarchy

Interface HasHierarchicalDataProvider<T>

Type Parameters:

T - the item data type

All Superinterfaces:

Serializable

All Known Implementing Classes:

TreeGrid

public interface HasHierarchicalDataProvider<T>
extends Serializable

A generic interface for hierarchical listing components that use a data provider for showing hierarchical data.

Since:

1.2

Author:

Vaadin Ltd

Method Summary

Modifier and Type	Method and Description
HierarchicalDataProvider<T,SerializablePredicate<T>>	getDataProvider()
default TreeData<T>	getTreeData() Gets the backing TreeData instance of the data provider, if the data provider is a TreeDataProvider.
void	setDataProvider(DataProvider<T,?> dataProvider) Deprecated. Use setDataProvider(HierarchicalDataProvider) instead as the data should be hierarchical
void	setDataProvider(HierarchicalDataProvider<T,?> hierarchicalDataProvider) Sets the hierarchical data provider for this listing.
default void	setItems(Collection<T> rootItems, ValueProvider<T,Collection<T>> childItemProvider) Sets the root data items of this component provided as a collection and recursively populates them with child items with the given value provider.
default void	setItems(Stream<T> rootItems, ValueProvider<T,Stream<T>> childItemProvider) Sets the root data items of this component provided as a stream and recursively populates them with child items with the given value provider.
default void	setTreeData(TreeData<T> treeData) Sets a new TreeDataProvider wrapping the given TreeData.

Method Detail

getDataProvider

HierarchicalDataProvider<T,SerializablePredicate<T>> getDataProvider()

setTreeData

default void setTreeData(TreeData<T> treeData)

Sets a new TreeDataProvider wrapping the given TreeData.

Parameters:

treeData - the tree data to set

getTreeData

default TreeData<T> getTreeData()

Gets the backing TreeData instance of the data provider, if the data provider is a TreeDataProvider.

Returns:

the TreeData instance used by the data provider

Throws:

IllegalStateException - if the type of the data provider is not TreeDataProvider

setItems

default void setItems(Collection<T> rootItems,
                      ValueProvider<T,Collection<T>> childItemProvider)

Sets the root data items of this component provided as a collection and recursively populates them with child items with the given value provider.

The provided items are wrapped into a TreeDataProvider backed by a flat TreeData structure. The data provider instance is used as a parameter for the setDataProvider(DataProvider) method. It means that the items collection can be accessed later on via getTreeData():

 
 Collection<Person> grandParents = getGrandParents();
 HasHierarchicalDataProvider<Person> treeGrid = new TreeGrid<>();
 treeGrid.setItems(grandParents, Person::getChildren);
 ...

 TreeData<Person> data = treeGrid.getTreeData();
 
 

The returned TreeData instance may be used as-is to add, remove or modify items in the hierarchy. These modifications to the object are not automatically reflected back to the TreeGrid. Items modified should be refreshed with DataProvider.refreshItem(Object) and when adding or removing items DataProvider.refreshAll() should be called.

Parameters:

rootItems - the root items to display, not null

childItemProvider - the value provider used to recursively populate the given root items with child items, not null

setItems

default void setItems(Stream<T> rootItems,
                      ValueProvider<T,Stream<T>> childItemProvider)

Sets the root data items of this component provided as a stream and recursively populates them with child items with the given value provider.

The provided items are wrapped into a TreeDataProvider backed by a flat TreeData structure. The data provider instance is used as a parameter for the setDataProvider(DataProvider) method. It means that the items collection can be accessed later on via getTreeData():

 
 Stream<Person> grandParents = getGrandParents();
 HasHierarchicalDataProvider<Person> treeGrid = new TreeGrid<>();
 treeGrid.setItems(grandParents, Person::getChildren);
 ...

 TreeData<Person> data = treeGrid.getTreeData();
 
 

The returned TreeData instance may be used as-is to add, remove or modify items in the hierarchy. These modifications to the object are not automatically reflected back to the TreeGrid. Items modified should be refreshed with DataProvider.refreshItem(Object) and when adding or removing items DataProvider.refreshAll() should be called.

Parameters:

rootItems - the root items to display, not null

childItemProvider - the value provider used to recursively populate the given root items with child items, not null

setDataProvider

@Deprecated
void setDataProvider(DataProvider<T,?> dataProvider)

Deprecated. Use setDataProvider(HierarchicalDataProvider) instead as the data should be hierarchical

Sets the data provider for this listing. The data provider is queried for displayed items as needed.

NOTE: This method is here for backwards compatibility, but the implementation for it will most likely throw if the data provider is not a HierarchicalDataProvider.

Parameters:

dataProvider - the data provider, not null

setDataProvider

void setDataProvider(HierarchicalDataProvider<T,?> hierarchicalDataProvider)

Sets the hierarchical data provider for this listing. The data provider provides the items and the hierarchy as needed.

Parameters:

hierarchicalDataProvider - the hierarchical data provider to use, not null