com.vaadin.flow.data.provider

Class AbstractComponentDataGenerator<T>

java.lang.Object

com.vaadin.flow.data.provider.AbstractComponentDataGenerator<T>

Type Parameters:

T - the data type

All Implemented Interfaces:

DataGenerator<T>, Serializable

Direct Known Subclasses:

ComponentDataGenerator

public abstract class AbstractComponentDataGenerator<T>
extends Object
implements DataGenerator<T>

Abstract class used as base for DataGenerators that need to manage the lifecycle of components, according to what items are requested or destroyed.

Since:

1.0.

Author:

Vaadin Ltd

See Also:

Serialized Form

Constructor Summary

Constructors

Constructor and Description
AbstractComponentDataGenerator()

Method Summary

Modifier and Type	Method and Description
protected abstract Component	createComponent(T item) Creates a new component based on the provided item.
void	destroyAllData() Informs the DataGenerator that all data has been dropped.
void	destroyData(T item) Informs the DataGenerator that the given data item has been dropped and is no longer needed.
protected abstract Element	getContainer() Gets the element where the generated components will be attached to.
protected abstract String	getItemKey(T item) Gets a unique key for a given item.
protected Component	getRenderedComponent(String itemKey)
void	refreshData(T item) Informs the DataGenerator that a data object has been updated.
protected void	registerRenderedComponent(String itemKey, Component component) Appends the component to the container and registers it for future use during the lifecycle of the generator.
protected Component	updateComponent(Component currentComponent, T item) Updates an existing component after the item has been updated.

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.DataGenerator

generateData

Constructor Detail

AbstractComponentDataGenerator

public AbstractComponentDataGenerator()

Method Detail

refreshData

public void refreshData(T item)

Description copied from interface: DataGenerator

Informs the DataGenerator that a data object has been updated. This method should update any unneeded information stored for given item.

Specified by:

refreshData in interface DataGenerator<T>

Parameters:

item - the updated item

destroyData

public void destroyData(T item)

Description copied from interface: DataGenerator

Informs the DataGenerator that the given data item has been dropped and is no longer needed. This method should clean up any unneeded information stored for this item.

Specified by:

destroyData in interface DataGenerator<T>

Parameters:

item - the dropped data item

destroyAllData

public void destroyAllData()

Description copied from interface: DataGenerator

Informs the DataGenerator that all data has been dropped. This method should clean up any unneeded information stored for items.

Specified by:

destroyAllData in interface DataGenerator<T>

getContainer

protected abstract Element getContainer()

Gets the element where the generated components will be attached to.

Returns:

the container

createComponent

protected abstract Component createComponent(T item)

Creates a new component based on the provided item.

Parameters:

item - the data item, possibly null

Returns:

a Component which represents the provided item

updateComponent

protected Component updateComponent(Component currentComponent,
                                    T item)

Updates an existing component after the item has been updated. By default, it creates a new component instance via createComponent(Object).

Parameters:

currentComponent - the current component used to represent the item, not null

item - the updated item

Returns:

the component that should represent the updated item, not null

getItemKey

protected abstract String getItemKey(T item)

Gets a unique key for a given item. Items with the same keys are considered equal.

Parameters:

item - the model item

Returns:

a unique key for the item

registerRenderedComponent

protected void registerRenderedComponent(String itemKey,
                                         Component component)

Appends the component to the container and registers it for future use during the lifecycle of the generator.

Parameters:

itemKey - the key of the model item

component - the component to be attached to the container

getRenderedComponent

protected Component getRenderedComponent(String itemKey)