org.apache.wicket.markup.html.form
Class DropDownChoice

java.lang.Object
  org.apache.wicket.Component
      org.apache.wicket.MarkupContainer
          org.apache.wicket.markup.html.WebMarkupContainer
              org.apache.wicket.markup.html.form.LabeledWebMarkupContainer
                  org.apache.wicket.markup.html.form.FormComponent
                      org.apache.wicket.markup.html.form.AbstractSingleSelectChoice
                          org.apache.wicket.markup.html.form.DropDownChoice

All Implemented Interfaces:

java.io.Serializable, IClusterable, IConverterLocator, IRequestListener, IFormVisitorParticipant, ILabelProvider, IOnChangeListener

Direct Known Subclasses:

ListChoice

public class DropDownChoice
extends AbstractSingleSelectChoice
implements IOnChangeListener

A choice implemented as a dropdown menu/list.

Java:

 List SITES = Arrays.asList(new String[] { "The Server Side", "Java Lobby", "Java.Net" });
 
 // Add a dropdown choice component that uses Input's 'site' property to designate the
 // current selection, and that uses the SITES list for the available options.
 // Note that when the selection is null, Wicket will lookup a localized string to
 // represent this null with key: "id + '.null'". In this case, this is 'site.null'
 // which can be found in DropDownChoicePage.properties
 form.add(new DropDownChoice("site", SITES));
 

HTML:

        <select wicket:id="site">
                <option>site 1</option>
                <option>site 2</option>
        </select>
 

You can can extend this class and override method wantOnSelectionChangedNotifications() to force server roundtrips on each selection change.

Author:

Jonathan Locke, Eelco Hillenius, Johan Compagner

See Also:

Serialized Form

Nested Class Summary

Nested classes/interfaces inherited from class org.apache.wicket.markup.html.form.FormComponent

FormComponent.AbstractVisitor, FormComponent.IVisitor

Nested classes/interfaces inherited from class org.apache.wicket.Component

Component.ComponentModelChange, Component.EnabledChange, Component.VisibilityChange

Field Summary

Fields inherited from class org.apache.wicket.markup.html.form.AbstractSingleSelectChoice

NO_SELECTION_VALUE

Fields inherited from class org.apache.wicket.markup.html.form.FormComponent

FLAG_CONVERT_EMPTY_INPUT_STRING_TO_NULL, VALUE_SEPARATOR

Fields inherited from class org.apache.wicket.Component

ENABLE, FLAG_RESERVED1, FLAG_RESERVED2, FLAG_RESERVED3, FLAG_RESERVED4, FLAG_RESERVED5, FLAG_RESERVED6, FLAG_RESERVED7, FLAG_RESERVED8, PATH_SEPARATOR, RENDER

Fields inherited from interface org.apache.wicket.markup.html.form.IOnChangeListener

INTERFACE

Constructor Summary

DropDownChoice(java.lang.String id)

DropDownChoice(java.lang.String id, IModel choices)

DropDownChoice(java.lang.String id, IModel choices, IChoiceRenderer renderer)

DropDownChoice(java.lang.String id, IModel model, IModel choices)

DropDownChoice(java.lang.String id, IModel model, IModel choices, IChoiceRenderer renderer)

DropDownChoice(java.lang.String id, IModel model, java.util.List choices)

DropDownChoice(java.lang.String id, IModel model, java.util.List data, IChoiceRenderer renderer)

DropDownChoice(java.lang.String id, java.util.List choices)

DropDownChoice(java.lang.String id, java.util.List data, IChoiceRenderer renderer)

Method Summary

protected void	appendOptionHtml(AppendingStringBuffer buffer, java.lang.Object choice, int index, java.lang.String selected) Generates and appends html for a single choice into the provided buffer
protected void	detachModel() Detaches the model for this component if it is detachable.
protected java.lang.CharSequence	escapeOptionHtml(java.lang.String displayValue) Method to override if you want special escaping of the options html.
IChoiceRenderer	getChoiceRenderer()
java.util.List	getChoices()
protected boolean	getStatelessHint() Returns whether the component can be stateless.
protected boolean	isDisabled(java.lang.Object object, int index, java.lang.String selected) Gets whether the given value is disabled.
protected boolean	localizeDisplayValues() Override this method if you want to localize the display values of the generated options.
protected void	onComponentTag(ComponentTag tag) Processes the component tag.
protected void	onComponentTagBody(MarkupStream markupStream, ComponentTag openTag) Handle the container's body.
void	onSelectionChanged() Called when a selection changes.
protected void	onSelectionChanged(java.lang.Object newSelection) Template method that can be overridden by clients that implement IOnChangeListener to be notified by onChange events of a select element.
org.apache.wicket.markup.html.form.AbstractChoice	setChoiceRenderer(IChoiceRenderer renderer) Set the choice renderer to be used.
org.apache.wicket.markup.html.form.AbstractChoice	setChoices(IModel choices) Sets the list of choices
org.apache.wicket.markup.html.form.AbstractChoice	setChoices(java.util.List choices) Sets the list of choices.
protected boolean	supportsPersistence()
protected boolean	wantOnSelectionChangedNotifications() Whether this component's onSelectionChanged event handler should be called using javascript window.location if the selection changes.

Methods inherited from class org.apache.wicket.markup.html.form.AbstractSingleSelectChoice

convertChoiceIdToChoice, convertValue, getDefaultChoice, getModelValue, isNullValid, isSelected, setNullValid

Methods inherited from class org.apache.wicket.markup.html.form.FormComponent

add, checkRequired, clearInput, convertInput, error, getBehaviors, getConvertedInput, getForm, getInput, getInputAsArray, getInputName, getRawInput, getType, getValidatorKeyPrefix, getValidators, getValue, hasRawInput, inputAsInt, inputAsInt, inputAsIntArray, inputChanged, internalOnModelChanged, invalid, isInputNullable, isMultiPart, isPersistent, isRequired, isValid, onDetach, onDisabled, onInvalid, onValid, processChildren, processInput, setConvertedInput, setLabel, setModelValue, setModelValue, setPersistent, setRequired, setType, shouldTrimInput, trim, updateModel, valid, validate, validateRequired, validateValidators, visitFormComponentsPostOrder

Methods inherited from class org.apache.wicket.markup.html.form.LabeledWebMarkupContainer

getLabel, setLabelInternal

Methods inherited from class org.apache.wicket.markup.html.WebMarkupContainer

getMarkupType, getWebPage

Methods inherited from class org.apache.wicket.MarkupContainer

add, addOrReplace, autoAdd, autoAdd, contains, findMarkupStream, get, getAssociatedMarkupStream, getMarkupStream, hasAssociatedMarkup, internalAdd, isTransparentResolver, iterator, iterator, newMarkupResourceStream, onRender, remove, remove, removeAll, renderAll, renderAssociatedMarkup, renderComponentTagBody, replace, setMarkupStream, setModel, size, toString, toString, visitChildren, visitChildren

Methods inherited from class org.apache.wicket.Component

add, addStateChange, afterRender, beforeRender, callOnBeforeRenderIfNotVisible, checkComponentTag, checkComponentTagAttribute, checkHierarchyChange, continueToOriginalDestination, debug, detach, detachBehaviors, detachModels, determineVisibility, error, exceptionMessage, fatal, findPage, findParent, findParentWithAssociatedMarkup, getApplication, getBehaviors, getBehaviorsRawList, getClassRelativePath, getComponentBorder, getConverter, getConverter, getEscapeModelStrings, getFeedbackMessage, getFlag, getFlag, getId, getInnermostModel, getInnermostModel, getLocale, getLocalizer, getMarkupAttributes, getMarkupId, getMarkupId, getMetaData, getModel, getModelComparator, getModelObject, getModelObjectAsString, getModelObjectAsString, getOutputMarkupId, getOutputMarkupPlaceholderTag, getPage, getPageFactory, getPageRelativePath, getParent, getPath, getRenderBodyOnly, getRequest, getRequestCycle, getResponse, getSession, getSizeInBytes, getString, getString, getString, getStyle, getVariation, hasBeenRendered, hasErrorMessage, hasFeedbackMessage, info, initModel, internalAttach, internalDetach, internalOnAttach, internalOnDetach, isActionAuthorized, isAncestorOf, isAttached, isBehaviorAccepted, isEnableAllowed, isEnabled, isIgnoreAttributeModifier, isRenderAllowed, isStateless, isVersioned, isVisibilityAllowed, isVisible, isVisibleInHierarchy, locateMarkupStream, markAttached, markRendering, modelChanged, modelChanging, newPage, newPage, onAfterRender, onAttach, onBeforeRender, onBeginRequest, onEndRequest, onModelChanged, onModelChanging, prepareForRender, redirectToInterceptPage, remove, remove, render, render, renderComponent, renderComponent, renderComponentTag, rendered, renderHead, replaceComponentTagBody, replaceWith, sameInnermostModel, sameInnermostModel, setAuto, setComponentBorder, setEnabled, setEscapeModelStrings, setFlag, setFlag, setIgnoreAttributeModifier, setMarkupId, setMetaData, setModelObject, setOutputMarkupId, setOutputMarkupPlaceholderTag, setRedirect, setRenderBodyOnly, setResponsePage, setResponsePage, setResponsePage, setVersioned, setVisibilityAllowed, setVisible, urlFor, urlFor, urlFor, urlFor, urlFor, urlFor, visitParents, warn, wrap

Methods inherited from class java.lang.Object

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

Constructor Detail

DropDownChoice

public DropDownChoice(java.lang.String id)

See Also:

AbstractChoice.AbstractChoice(String)

DropDownChoice

public DropDownChoice(java.lang.String id,
                      java.util.List choices)

See Also:

AbstractChoice.AbstractChoice(String, List)

DropDownChoice

public DropDownChoice(java.lang.String id,
                      java.util.List data,
                      IChoiceRenderer renderer)

See Also:

AbstractChoice.AbstractChoice(String, List,IChoiceRenderer)

DropDownChoice

public DropDownChoice(java.lang.String id,
                      IModel model,
                      java.util.List choices)

See Also:

AbstractChoice.AbstractChoice(String, IModel, List)

DropDownChoice

public DropDownChoice(java.lang.String id,
                      IModel model,
                      java.util.List data,
                      IChoiceRenderer renderer)

See Also:

AbstractChoice.AbstractChoice(String, IModel, List, IChoiceRenderer)

DropDownChoice

public DropDownChoice(java.lang.String id,
                      IModel choices)

See Also:

AbstractChoice.AbstractChoice(String, IModel)

DropDownChoice

public DropDownChoice(java.lang.String id,
                      IModel model,
                      IModel choices)

See Also:

AbstractChoice.AbstractChoice(String, IModel,IModel)

DropDownChoice

public DropDownChoice(java.lang.String id,
                      IModel choices,
                      IChoiceRenderer renderer)

See Also:

AbstractChoice.AbstractChoice(String, IModel,IChoiceRenderer)

DropDownChoice

public DropDownChoice(java.lang.String id,
                      IModel model,
                      IModel choices,
                      IChoiceRenderer renderer)

See Also:

AbstractChoice.AbstractChoice(String, IModel, IModel,IChoiceRenderer)

Method Detail

onSelectionChanged

public final void onSelectionChanged()

Called when a selection changes.

Specified by:

onSelectionChanged in interface IOnChangeListener

onComponentTag

protected void onComponentTag(ComponentTag tag)

Processes the component tag.

Overrides:

onComponentTag in class FormComponent

Parameters:

tag - Tag to modify

See Also:

Component.onComponentTag(org.apache.wicket.markup.ComponentTag)

onSelectionChanged

protected void onSelectionChanged(java.lang.Object newSelection)

Template method that can be overridden by clients that implement IOnChangeListener to be notified by onChange events of a select element. This method does nothing by default.

Called when a option is selected of a dropdown list that wants to be notified of this event. This method is to be implemented by clients that want to be notified of selection events.

Parameters:

newSelection - The newly selected object of the backing model NOTE this is the same as you would get by calling getModelObject() if the new selection were current

wantOnSelectionChangedNotifications

protected boolean wantOnSelectionChangedNotifications()

Whether this component's onSelectionChanged event handler should be called using javascript window.location if the selection changes. If true, a roundtrip will be generated with each selection change, resulting in the model being updated (of just this component) and onSelectionChanged being called. This method returns false by default. If you wish to use Ajax instead, let wantOnSelectionChangedNotifications() return false and add an AjaxFormComponentUpdatingBehavior to the component using the onchange event.

Returns:

True if this component's onSelectionChanged event handler should called using javascript if the selection changes

getStatelessHint

protected boolean getStatelessHint()

Description copied from class: Component

Returns whether the component can be stateless. Also the component behaviors must be stateless, otherwise the component will be treat as stateful. In order for page to be stateless (and not to be stored in session), all components (and component behaviors) must be stateless.

Overrides:

getStatelessHint in class Component

Returns:

whether the component can be stateless

See Also:

Component.getStatelessHint()

getChoices

public java.util.List getChoices()

Returns:

The collection of object that this choice has

setChoices

public final org.apache.wicket.markup.html.form.AbstractChoice setChoices(IModel choices)

Sets the list of choices

Parameters:

choices - model representing the list of choices

Returns:

this for chaining

setChoices

public final org.apache.wicket.markup.html.form.AbstractChoice setChoices(java.util.List choices)

Sets the list of choices.

Parameters:

choices - the list of choices

Returns:

this for chaining

getChoiceRenderer

public final IChoiceRenderer getChoiceRenderer()

Returns:

The IChoiceRenderer used for rendering the data objects

setChoiceRenderer

public final org.apache.wicket.markup.html.form.AbstractChoice setChoiceRenderer(IChoiceRenderer renderer)

Set the choice renderer to be used.

Parameters:

renderer -

Returns:

this for chaining

detachModel

protected void detachModel()

Description copied from class: Component

Detaches the model for this component if it is detachable.

Overrides:

detachModel in class Component

See Also:

Component.detachModel()

isDisabled

protected boolean isDisabled(java.lang.Object object,
                             int index,
                             java.lang.String selected)

Gets whether the given value is disabled. This default implementation always returns false.

Parameters:

object - The object to check

index - The index in the choices collection this object is in.

selected - The currently selected string value

Returns:

Whether the given value represents the current selection

onComponentTagBody

protected void onComponentTagBody(MarkupStream markupStream,
                                  ComponentTag openTag)

Handle the container's body.

Overrides:

onComponentTagBody in class MarkupContainer

Parameters:

markupStream - The markup stream

openTag - The open tag for the body

See Also:

Component.onComponentTagBody(MarkupStream, ComponentTag)

appendOptionHtml

protected void appendOptionHtml(AppendingStringBuffer buffer,
                                java.lang.Object choice,
                                int index,
                                java.lang.String selected)

Generates and appends html for a single choice into the provided buffer

Parameters:

buffer - Appending string buffer that will have the generated html appended

choice - Choice object

index - The index of this option

selected - The currently selected string value

escapeOptionHtml

protected java.lang.CharSequence escapeOptionHtml(java.lang.String displayValue)

Method to override if you want special escaping of the options html.

Parameters:

displayValue -

Returns:

The escaped display value

supportsPersistence

protected boolean supportsPersistence()

Overrides:

supportsPersistence in class FormComponent

Returns:

True if this type of FormComponent can be persisted.

See Also:

FormComponent.supportsPersistence()

localizeDisplayValues

protected boolean localizeDisplayValues()

Override this method if you want to localize the display values of the generated options. By default false is returned so that the display values of options are not tested if they have a i18n key.

Returns:

true If you want to localize the display values, default == false