com.vaadin.flow.component.select

Class Select<T>

java.lang.Object

com.vaadin.flow.component.Component

com.vaadin.flow.component.AbstractField<C,T>

com.vaadin.flow.component.AbstractSinglePropertyField<R,T>

com.vaadin.flow.component.select.generated.GeneratedVaadinSelect<Select<T>,T>

com.vaadin.flow.component.select.Select<T>

Type Parameters:

T - the type of the items for the select

All Implemented Interfaces:

com.vaadin.flow.component.AttachNotifier, com.vaadin.flow.component.BlurNotifier<Select<T>>, com.vaadin.flow.component.DetachNotifier, com.vaadin.flow.component.Focusable<Select<T>>, com.vaadin.flow.component.FocusNotifier<Select<T>>, com.vaadin.flow.component.HasComponents, com.vaadin.flow.component.HasElement, com.vaadin.flow.component.HasEnabled, com.vaadin.flow.component.HasHelper, com.vaadin.flow.component.HasLabel, com.vaadin.flow.component.HasSize, com.vaadin.flow.component.HasStyle, com.vaadin.flow.component.HasValidation, com.vaadin.flow.component.HasValue<com.vaadin.flow.component.AbstractField.ComponentValueChangeEvent<Select<T>,T>,T>, com.vaadin.flow.component.HasValueAndElement<com.vaadin.flow.component.AbstractField.ComponentValueChangeEvent<Select<T>,T>,T>, HasClientValidation, com.vaadin.flow.data.binder.HasDataProvider<T>, com.vaadin.flow.data.binder.HasItems<T>, com.vaadin.flow.data.binder.HasItemsAndComponents<T>, com.vaadin.flow.data.binder.HasValidator<T>, com.vaadin.flow.data.selection.SingleSelect<Select<T>,T>, Serializable

@JavaScript(value="frontend://selectConnector.js")
public class Select<T>
extends GeneratedVaadinSelect<Select<T>,T>
implements com.vaadin.flow.data.binder.HasDataProvider<T>, com.vaadin.flow.data.binder.HasItemsAndComponents<T>, com.vaadin.flow.component.HasSize, com.vaadin.flow.component.HasValidation, com.vaadin.flow.data.selection.SingleSelect<Select<T>,T>, com.vaadin.flow.component.HasHelper, com.vaadin.flow.component.HasLabel, com.vaadin.flow.data.binder.HasValidator<T>, HasClientValidation

A customizable drop-down select component similar to a native browser select.

This is a server side Java integration for <vaadin-select> web component.

For usage examples, see the demo in vaadin.com.

Author:

Vaadin Ltd.

See Also:

Serialized Form

Nested Class Summary

Nested classes/interfaces inherited from class com.vaadin.flow.component.select.generated.GeneratedVaadinSelect

GeneratedVaadinSelect.InvalidChangeEvent<R extends GeneratedVaadinSelect<R,?>>, GeneratedVaadinSelect.OpenedChangeEvent<R extends GeneratedVaadinSelect<R,?>>

Nested classes/interfaces inherited from class com.vaadin.flow.component.AbstractField

com.vaadin.flow.component.AbstractField.ComponentValueChangeEvent<C extends com.vaadin.flow.component.Component,V>

Nested classes/interfaces inherited from interface com.vaadin.flow.data.binder.HasItemsAndComponents

com.vaadin.flow.data.binder.HasItemsAndComponents.ItemComponent<T>

Nested classes/interfaces inherited from interface com.vaadin.flow.component.HasValue

com.vaadin.flow.component.HasValue.ValueChangeEvent<V>, com.vaadin.flow.component.HasValue.ValueChangeListener<E extends com.vaadin.flow.component.HasValue.ValueChangeEvent<?>>

Nested classes/interfaces inherited from interface com.vaadin.flow.component.shared.HasClientValidation

HasClientValidation.ClientValidatedEvent

Nested classes/interfaces inherited from interface com.vaadin.flow.component.BlurNotifier

com.vaadin.flow.component.BlurNotifier.BlurEvent<C extends com.vaadin.flow.component.Component>

Nested classes/interfaces inherited from interface com.vaadin.flow.component.FocusNotifier

com.vaadin.flow.component.FocusNotifier.FocusEvent<C extends com.vaadin.flow.component.Component>

Field Summary

Fields

Modifier and Type	Field and Description
static String	LABEL_ATTRIBUTE

Constructor Summary

Constructors

Constructor and Description
Select() Constructs a select.
Select(T... items) Constructs a select with the given items.

Method Summary

Modifier and Type	Method and Description
void	add(com.vaadin.flow.component.Component... components)
void	addComponentAsFirst(com.vaadin.flow.component.Component component)
void	addComponentAtIndex(int index, com.vaadin.flow.component.Component component)
void	addComponents(T afterItem, com.vaadin.flow.component.Component... components)
void	addToPrefix(com.vaadin.flow.component.Component... components) Adds the given components as children of this component at the slot 'prefix'.
com.vaadin.flow.shared.Registration	addValidationStatusChangeListener(com.vaadin.flow.data.binder.ValidationStatusChangeListener<T> listener)
Stream<com.vaadin.flow.component.Component>	getChildren()
com.vaadin.flow.data.provider.DataProvider<T,?>	getDataProvider() Gets the data provider.
String	getEmptySelectionCaption()
String	getErrorMessage() Gets the error message to show to the user on invalid selection
com.vaadin.flow.function.SerializablePredicate<T>	getItemEnabledProvider() Returns the item enabled predicate.
com.vaadin.flow.component.ItemLabelGenerator<T>	getItemLabelGenerator() Gets the item label generator.
int	getItemPosition(T item)
com.vaadin.flow.data.renderer.ComponentRenderer<? extends com.vaadin.flow.component.Component,T>	getItemRenderer() Returns the item component renderer.
String	getLabel() Gets the string for the label element.
String	getPlaceholder() Gets the placeholder hint set for the user.
protected boolean	hasValidValue()
boolean	isAutofocus() Gets whether this select has been set to autofocus when the page loads.
boolean	isEmptySelectionAllowed() Returns whether the user is allowed to select nothing.
protected boolean	isEnforcedFieldValidationEnabled()
boolean	isInvalid() Gets whether the select is currently in invalid state.
boolean	isRequiredIndicatorVisible() NOTE: The required indicator will not be visible, if the setLabel(String) property is not set for the select.
protected void	onAttach(com.vaadin.flow.component.AttachEvent attachEvent)
void	onEnabledStateChanged(boolean enabled)
void	prependComponents(T beforeItem, com.vaadin.flow.component.Component... components)
void	remove(com.vaadin.flow.component.Component... components) Removes the given child components from this component.
void	removeAll() Removes all child components that are not items.
void	setAutofocus(boolean autofocus) Sets the select to have focus when the page loads.
void	setDataProvider(com.vaadin.flow.data.provider.DataProvider<T,?> dataProvider)
void	setEmptySelectionAllowed(boolean emptySelectionAllowed) Sets whether the user is allowed to select nothing.
void	setEmptySelectionCaption(String emptySelectionCaption) Sets the empty selection caption when setEmptySelectionAllowed(boolean) has been enabled.
void	setErrorMessage(String errorMessage) Sets the error message to show to the user on invalid selection.
void	setInvalid(boolean invalid) Sets the select to show as invalid state and display error message.
void	setItemEnabledProvider(com.vaadin.flow.function.SerializablePredicate<T> itemEnabledProvider) Sets the item enabled predicate for this select.
void	setItemLabelGenerator(com.vaadin.flow.component.ItemLabelGenerator<T> itemLabelGenerator) Sets the item label generator.
void	setLabel(String label) Sets the string for the label element.
void	setPlaceholder(String placeholder) Sets the placeholder hint for the user.
void	setRenderer(com.vaadin.flow.data.renderer.ComponentRenderer<? extends com.vaadin.flow.component.Component,T> renderer) Sets the item renderer for this select group.
void	setRequiredIndicatorVisible(boolean requiredIndicatorVisible) NOTE: The required indicator will not be visible, if the setLabel(String) property is not set for the select.
void	setTextRenderer(com.vaadin.flow.component.ItemLabelGenerator<T> itemLabelGenerator) Convenience setter for creating a TextRenderer from the given function that converts the item to a string.
protected void	validate() Description copied from corresponding location in WebComponent:

Methods inherited from class com.vaadin.flow.component.select.generated.GeneratedVaadinSelect

addInvalidChangeListener, addOpenedChangeListener, getErrorMessageString, getLabelString, getNameString, getPlaceholderString, isAutofocusBoolean, isDisabledBoolean, isInvalidBoolean, isOpenedBoolean, isReadonlyBoolean, isRequiredBoolean, render, setDisabled, setName, setOpened, setReadonly, setRequired

Methods inherited from class com.vaadin.flow.component.AbstractSinglePropertyField

getSynchronizationRegistration, setPresentationValue, setSynchronizedEvent

Methods inherited from class com.vaadin.flow.component.AbstractField

addValueChangeListener, getEmptyValue, getValue, isEmpty, setModelValue, setValue, valueEquals

Methods inherited from class com.vaadin.flow.component.Component

addListener, fireEvent, from, get, getElement, getEventBus, getId, getLocale, getParent, getTranslation, getTranslation, getTranslation, getTranslation, getUI, hasListener, isAttached, isTemplateMapped, isVisible, onDetach, set, setElement, setId, setVisible

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.binder.HasDataProvider

setItems

Methods inherited from interface com.vaadin.flow.component.HasComponents

add

Methods inherited from interface com.vaadin.flow.data.binder.HasItems

setItems, setItems

Methods inherited from interface com.vaadin.flow.component.HasSize

getCssSize, getHeight, getHeightUnit, getMaxHeight, getMaxWidth, getMinHeight, getMinWidth, getWidth, getWidthUnit, setHeight, setHeight, setHeightFull, setMaxHeight, setMaxHeight, setMaxWidth, setMaxWidth, setMinHeight, setMinHeight, setMinWidth, setMinWidth, setSizeFull, setSizeUndefined, setWidth, setWidth, setWidthFull

Methods inherited from interface com.vaadin.flow.component.HasValueAndElement

isReadOnly, setReadOnly

Methods inherited from interface com.vaadin.flow.component.HasValue

addValueChangeListener, clear, getEmptyValue, getOptionalValue, getValue, isEmpty, setValue

Methods inherited from interface com.vaadin.flow.component.HasEnabled

isEnabled, setEnabled

Methods inherited from interface com.vaadin.flow.component.HasHelper

getHelperComponent, getHelperText, setHelperComponent, setHelperText

Methods inherited from interface com.vaadin.flow.data.binder.HasValidator

getDefaultValidator

Methods inherited from interface com.vaadin.flow.component.shared.HasClientValidation

addClientValidatedEventListener

Methods inherited from interface com.vaadin.flow.component.HasStyle

addClassName, addClassNames, getClassName, getClassNames, getStyle, hasClassName, removeClassName, removeClassNames, setClassName, setClassName

Methods inherited from interface com.vaadin.flow.component.Focusable

addFocusShortcut, blur, focus, getTabIndex, setTabIndex

Methods inherited from interface com.vaadin.flow.component.BlurNotifier

addBlurListener

Methods inherited from interface com.vaadin.flow.component.FocusNotifier

addFocusListener

Methods inherited from interface com.vaadin.flow.component.AttachNotifier

addAttachListener

Methods inherited from interface com.vaadin.flow.component.DetachNotifier

addDetachListener

Field Detail

LABEL_ATTRIBUTE

public static final String LABEL_ATTRIBUTE

See Also:

Constant Field Values

Constructor Detail

Select

public Select()

Constructs a select.

Select

public Select(T... items)

Constructs a select with the given items.

Parameters:

items - the items for the select

Method Detail

getItemRenderer

public com.vaadin.flow.data.renderer.ComponentRenderer<? extends com.vaadin.flow.component.Component,T> getItemRenderer()

Returns the item component renderer.

Returns:

the item renderer or null if none set

See Also:

setRenderer(ComponentRenderer)

setRenderer

public void setRenderer(com.vaadin.flow.data.renderer.ComponentRenderer<? extends com.vaadin.flow.component.Component,T> renderer)

Sets the item renderer for this select group. The renderer is applied to each item to create a component which represents the item option in the select's drop down.

Default is null which means that the item's Object.toString() method is used and set as the text content of the vaadin item element.

Parameters:

renderer - the item renderer, or null to clear

setTextRenderer

public void setTextRenderer(com.vaadin.flow.component.ItemLabelGenerator<T> itemLabelGenerator)

Convenience setter for creating a TextRenderer from the given function that converts the item to a string.

NOTE: even though this accepts an ItemLabelGenerator, this is not the same as setItemLabelGenerator(ItemLabelGenerator) which does a different thing.

Parameters:

itemLabelGenerator - the function that creates the text content from the item, not null

setEmptySelectionAllowed

public void setEmptySelectionAllowed(boolean emptySelectionAllowed)

Sets whether the user is allowed to select nothing. When set true a special empty item is shown to the user.

Default is false. The empty selection item can be customized with setEmptySelectionCaption(String).

Parameters:

emptySelectionAllowed - true to allow not selecting anything, false to require selection

See Also:

setEmptySelectionCaption(String)

isEmptySelectionAllowed

public boolean isEmptySelectionAllowed()

Returns whether the user is allowed to select nothing.

Returns:

true if empty selection is allowed, false otherwise

setEmptySelectionCaption

public void setEmptySelectionCaption(String emptySelectionCaption)

Sets the empty selection caption when setEmptySelectionAllowed(boolean) has been enabled. The caption is shown for the empty selection item in the drop down.

When the empty selection item is selected, the select shows the value provided by setItemLabelGenerator(ItemLabelGenerator) for the null item, or the string set with setPlaceholder(String) or an empty string if not placeholder is set.

Default is an empty string "", which will show the place holder when selected.

Parameters:

emptySelectionCaption - the empty selection caption to set, not null

See Also:

setEmptySelectionAllowed(boolean)

getEmptySelectionCaption

public String getEmptySelectionCaption()

getItemEnabledProvider

public com.vaadin.flow.function.SerializablePredicate<T> getItemEnabledProvider()

Returns the item enabled predicate.

Returns:

the item enabled predicate or null if not set

See Also:

setItemEnabledProvider(com.vaadin.flow.function.SerializablePredicate<T>)

setItemEnabledProvider

public void setItemEnabledProvider(com.vaadin.flow.function.SerializablePredicate<T> itemEnabledProvider)

Sets the item enabled predicate for this select. The predicate is applied to each item to determine whether the item should be enabled (true) or disabled (false). Disabled items are displayed as grayed out and the user cannot select them.

By default is null and all the items are enabled.

Parameters:

itemEnabledProvider - the item enable predicate or null to clear

getItemLabelGenerator

public com.vaadin.flow.component.ItemLabelGenerator<T> getItemLabelGenerator()

Gets the item label generator. It generates the text that is shown in the input part for the item when it has been selected.

Default is null.

Returns:

the item label generator, null if not set

setItemLabelGenerator

public void setItemLabelGenerator(com.vaadin.flow.component.ItemLabelGenerator<T> itemLabelGenerator)

Sets the item label generator. It generates the text that is shown in the input part for the item when it has been selected.

Default is null and the text content generated for the item with setRenderer(ComponentRenderer) is used instead.

Parameters:

itemLabelGenerator - the item label generator to set, or null to clear

getPlaceholder

public String getPlaceholder()

Gets the placeholder hint set for the user.

Returns:

the placeholder or null if none set

setPlaceholder

public void setPlaceholder(String placeholder)

Sets the placeholder hint for the user.

The placeholder will be displayed in the case that there is no item selected, or the selected item has an empty string label, or the selected item has no label and it's DOM content is empty.

Default value is null.

Overrides:

setPlaceholder in class GeneratedVaadinSelect<Select<T>,T>

Parameters:

placeholder - the placeholder to set, or null to remove

setLabel

public void setLabel(String label)

Sets the string for the label element.

NOTE: the label must be set for the required indicator to be visible.

Specified by:

setLabel in interface com.vaadin.flow.component.HasLabel

Overrides:

setLabel in class GeneratedVaadinSelect<Select<T>,T>

Parameters:

label - string or null to clear it

getLabel

public String getLabel()

Gets the string for the label element.

Specified by:

getLabel in interface com.vaadin.flow.component.HasLabel

Returns:

the label string, or null if not set

setAutofocus

public void setAutofocus(boolean autofocus)

Sets the select to have focus when the page loads.

Default is false.

Overrides:

setAutofocus in class GeneratedVaadinSelect<Select<T>,T>

Parameters:

autofocus - the autofocus to set

isAutofocus

public boolean isAutofocus()

Gets whether this select has been set to autofocus when the page loads.

Returns:

true if set to autofocus, false if not

setDataProvider

public void setDataProvider(com.vaadin.flow.data.provider.DataProvider<T,?> dataProvider)

Specified by:

setDataProvider in interface com.vaadin.flow.data.binder.HasDataProvider<T>

getDataProvider

public com.vaadin.flow.data.provider.DataProvider<T,?> getDataProvider()

Gets the data provider.

Returns:

the data provider, not null

onEnabledStateChanged

public void onEnabledStateChanged(boolean enabled)

Overrides:

onEnabledStateChanged in class com.vaadin.flow.component.Component

setRequiredIndicatorVisible

public void setRequiredIndicatorVisible(boolean requiredIndicatorVisible)

NOTE: The required indicator will not be visible, if the setLabel(String) property is not set for the select.

Specified by:

setRequiredIndicatorVisible in interface com.vaadin.flow.component.HasValue<com.vaadin.flow.component.AbstractField.ComponentValueChangeEvent<Select<T>,T>,T>

Specified by:

setRequiredIndicatorVisible in interface com.vaadin.flow.component.HasValueAndElement<com.vaadin.flow.component.AbstractField.ComponentValueChangeEvent<Select<T>,T>,T>

isRequiredIndicatorVisible

public boolean isRequiredIndicatorVisible()

NOTE: The required indicator will not be visible, if the setLabel(String) property is not set for the select.

Specified by:

isRequiredIndicatorVisible in interface com.vaadin.flow.component.HasValue<com.vaadin.flow.component.AbstractField.ComponentValueChangeEvent<Select<T>,T>,T>

Specified by:

isRequiredIndicatorVisible in interface com.vaadin.flow.component.HasValueAndElement<com.vaadin.flow.component.AbstractField.ComponentValueChangeEvent<Select<T>,T>,T>

setErrorMessage

public void setErrorMessage(String errorMessage)

Sets the error message to show to the user on invalid selection.

Specified by:

setErrorMessage in interface com.vaadin.flow.component.HasValidation

Overrides:

setErrorMessage in class GeneratedVaadinSelect<Select<T>,T>

Parameters:

errorMessage - the error message or null to clear it

getErrorMessage

public String getErrorMessage()

Gets the error message to show to the user on invalid selection

Specified by:

getErrorMessage in interface com.vaadin.flow.component.HasValidation

Returns:

the error message or null if not set

setInvalid

public void setInvalid(boolean invalid)

Sets the select to show as invalid state and display error message.

Specified by:

setInvalid in interface com.vaadin.flow.component.HasValidation

Overrides:

setInvalid in class GeneratedVaadinSelect<Select<T>,T>

Parameters:

invalid - true for invalid, false for valid

isInvalid

public boolean isInvalid()

Gets whether the select is currently in invalid state.

Specified by:

isInvalid in interface com.vaadin.flow.component.HasValidation

Returns:

true for invalid, false for valid

add

public void add(com.vaadin.flow.component.Component... components)

NOTE: If you add a component with the slot attribute set, it will be placed in the light-dom of the vaadin-select instead of the drop down, similar to addToPrefix(Component...)

Specified by:

add in interface com.vaadin.flow.component.HasComponents

addComponents

public void addComponents(T afterItem,
                          com.vaadin.flow.component.Component... components)

Specified by:

addComponents in interface com.vaadin.flow.data.binder.HasItemsAndComponents<T>

prependComponents

public void prependComponents(T beforeItem,
                              com.vaadin.flow.component.Component... components)

Specified by:

prependComponents in interface com.vaadin.flow.data.binder.HasItemsAndComponents<T>

getItemPosition

public int getItemPosition(T item)

Specified by:

getItemPosition in interface com.vaadin.flow.data.binder.HasItemsAndComponents<T>

addComponentAtIndex

public void addComponentAtIndex(int index,
                                com.vaadin.flow.component.Component component)

NOTE: If you add a component with the slot attribute set, it will be placed in the light-dom of the vaadin-select instead of the drop down, similar to addToPrefix(Component...)

Specified by:

addComponentAtIndex in interface com.vaadin.flow.component.HasComponents

addComponentAsFirst

public void addComponentAsFirst(com.vaadin.flow.component.Component component)

NOTE: If you add a component with the slot attribute set, it will be placed in the light-dom of the vaadin-select instead of the drop down, similar to addToPrefix(Component...)

Specified by:

addComponentAsFirst in interface com.vaadin.flow.component.HasComponents

addToPrefix

public void addToPrefix(com.vaadin.flow.component.Component... components)

Description copied from class: GeneratedVaadinSelect

Adds the given components as children of this component at the slot 'prefix'.

Overrides:

addToPrefix in class GeneratedVaadinSelect<Select<T>,T>

Parameters:

components - The components to add.

See Also:

MDN page about slots, Spec website about slots

getChildren

public Stream<com.vaadin.flow.component.Component> getChildren()

Overrides:

getChildren in class com.vaadin.flow.component.Component

remove

public void remove(com.vaadin.flow.component.Component... components)

Removes the given child components from this component.

NOTE: any component with the slot attribute will be attempted to removed from the light dom of the vaadin-select, instead of inside the options drop down.

Specified by:

remove in interface com.vaadin.flow.component.HasComponents

Overrides:

remove in class GeneratedVaadinSelect<Select<T>,T>

Parameters:

components - the components to remove

Throws:

IllegalArgumentException - if any of the components is not a child of this component

removeAll

public void removeAll()

Removes all child components that are not items. To remove all items, reset the data provider or use HasItems.setItems(Object[]).

NOTE: this will remove all non-items from the drop down and any slotted components from vaadin-select's light dom.

Specified by:

removeAll in interface com.vaadin.flow.component.HasComponents

Overrides:

removeAll in class GeneratedVaadinSelect<Select<T>,T>

See Also:

HasComponents.removeAll()

hasValidValue

protected boolean hasValidValue()

Overrides:

hasValidValue in class com.vaadin.flow.component.AbstractSinglePropertyField<Select<T>,T>

onAttach

protected void onAttach(com.vaadin.flow.component.AttachEvent attachEvent)

Overrides:

onAttach in class com.vaadin.flow.component.Component

validate

protected void validate()

Description copied from class: GeneratedVaadinSelect

Description copied from corresponding location in WebComponent:

Returns true if value is valid, and sets the invalid flag appropriately.

This function is not supported by Flow because it returns a boolean. Functions with return types different than void are not supported at this moment.

Overrides:

validate in class GeneratedVaadinSelect<Select<T>,T>

addValidationStatusChangeListener

public com.vaadin.flow.shared.Registration addValidationStatusChangeListener(com.vaadin.flow.data.binder.ValidationStatusChangeListener<T> listener)

Specified by:

addValidationStatusChangeListener in interface com.vaadin.flow.data.binder.HasValidator<T>

isEnforcedFieldValidationEnabled

protected boolean isEnforcedFieldValidationEnabled()