Package jakarta.faces.component

Class UICommand

java.lang.Object

jakarta.faces.component.UIComponent

jakarta.faces.component.UIComponentBase

jakarta.faces.component.UICommand

All Implemented Interfaces:

ActionSource, ActionSource2, PartialStateHolder, StateHolder, TransientStateHolder, ComponentSystemEventListener, FacesListener, SystemEventListenerHolder, EventListener

Direct Known Subclasses:

HtmlCommandButton, HtmlCommandLink, HtmlCommandScript

public class UICommand
extends UIComponentBase
implements ActionSource2

UICommand is a UIComponent that represents a user interface component which, when activated by the user, triggers an application specific "command" or "action". Such a component is typically rendered as a push button, a menu item, or a hyperlink.

When the decode() method of this UICommand, or its corresponding Renderer, detects that this control has been activated, it will queue an ActionEvent. Later on, the broadcast() method will ensure that this event is broadcast to all interested listeners.

Listeners will be invoked in the following order:

1. ActionListeners, in the order in which they were registered.
2. The "actionListener" MethodExpression (which will cover the "actionListener" that was set as a MethodBinding).
3. The default ActionListener, retrieved from the Application - and therefore, any attached "action" MethodExpression.

By default, the rendererType property must be set to "jakarta.faces.Button". This value can be changed by calling the setRendererType() method.

Field Summary

Fields

Modifier and Type	Field	Description
static final String	COMPONENT_FAMILY	The standard component family for this component.
static final String	COMPONENT_TYPE	The standard component type for this component.

Fields inherited from class jakarta.faces.component.UIComponent

ATTRS_WITH_DECLARED_DEFAULT_VALUES, BEANINFO_KEY, bindings, COMPOSITE_COMPONENT_TYPE_KEY, COMPOSITE_FACET_NAME, CURRENT_COMPONENT, CURRENT_COMPOSITE_COMPONENT, FACETS_KEY, HONOR_CURRENT_COMPONENT_ATTRIBUTES_PARAM_NAME, VIEW_LOCATION_KEY

Constructor Summary

Constructors

Constructor	Description
UICommand()	Create a new UICommand instance with default property values.

Method Summary

Modifier and Type	Method	Description
void	addActionListener(ActionListener listener)	Add a new ActionListener to the set of listeners interested in being notified when ActionEvents occur.
void	broadcast(FacesEvent event)	In addition to to the default UIComponent.broadcast(jakarta.faces.event.FacesEvent) processing, pass the ActionEvent being broadcast to the method referenced by actionListener (if any), and to the default ActionListener registered on the Application.
MethodBinding	getAction()	Deprecated. This has been replaced by getActionExpression().
MethodExpression	getActionExpression()	Return the MethodExpression pointing at the application action to be invoked, if this UIComponent is activated by the user, during the Apply Request Values or Invoke Application phase of the request processing lifecycle, depending on the value of the immediate property.
MethodBinding	getActionListener()	Deprecated. Use getActionListeners() instead.
ActionListener[]	getActionListeners()	Return the set of registered ActionListeners for this ActionSource instance.
String	getFamily()	Return the identifier of the component family to which this component belongs.
Object	getValue()	Returns the value property of the UICommand.
boolean	isImmediate()	The immediate flag.
void	queueEvent(FacesEvent event)	Intercept queueEvent and take the following action.
void	removeActionListener(ActionListener listener)	Remove an existing ActionListener (if any) from the set of listeners interested in being notified when ActionEvents occur.
void	setAction(MethodBinding action)	Deprecated. This has been replaced by setActionExpression(jakarta.el.MethodExpression).
void	setActionExpression(MethodExpression actionExpression)	Set the MethodExpression pointing at the appication action to be invoked, if this UIComponent is activated by the user, during the Apply Request Values or Invoke Application phase of the request processing lifecycle, depending on the value of the immediate property.
void	setActionListener(MethodBinding actionListener)	Deprecated. This has been replaced by addActionListener(jakarta.faces.event.ActionListener).
void	setImmediate(boolean immediate)	Set the "immediate execution" flag for this UIComponent.
void	setValue(Object value)	Sets the value property of the UICommand.

Methods inherited from class jakarta.faces.component.UIComponentBase

addClientBehavior, addFacesListener, clearInitialState, decode, encodeBegin, encodeChildren, encodeEnd, findComponent, getAttributes, getChildCount, getChildren, getClientBehaviors, getClientId, getDefaultEventName, getEventNames, getFacesContext, getFacesListeners, getFacet, getFacetCount, getFacets, getFacetsAndChildren, getId, getListenersForEventClass, getParent, getPassThroughAttributes, getRenderer, getRendererType, getRendersChildren, getValueBinding, invokeOnComponent, isRendered, isTransient, markInitialState, processDecodes, processRestoreState, processSaveState, processUpdates, processValidators, removeFacesListener, restoreAttachedState, restoreState, saveAttachedState, saveState, setId, setParent, setRendered, setRendererType, setTransient, setValueBinding, subscribeToEvent, unsubscribeFromEvent

Methods inherited from class jakarta.faces.component.UIComponent

encodeAll, getClientId, getCompositeComponentParent, getContainerClientId, getCurrentComponent, getCurrentCompositeComponent, getNamingContainer, getPassThroughAttributes, getResourceBundleMap, getStateHelper, getStateHelper, getTransientStateHelper, getTransientStateHelper, getValueExpression, initialStateMarked, isCompositeComponent, isInView, isVisitable, popComponentFromEL, processEvent, pushComponentToEL, restoreTransientState, saveTransientState, setInView, setValueExpression, visitTree

Methods inherited from class java.lang.Object

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

Field Details

COMPONENT_TYPE

public static final String COMPONENT_TYPE

The standard component type for this component.

See Also:

• Constant Field Values

COMPONENT_FAMILY

public static final String COMPONENT_FAMILY

The standard component family for this component.

See Also:

• Constant Field Values

Constructor Details

UICommand

public UICommand()

Create a new UICommand instance with default property values.

Method Details

getFamily

public String getFamily()

Description copied from class: UIComponent

Return the identifier of the component family to which this component belongs. This identifier, in conjunction with the value of the rendererType property, may be used to select the appropriate Renderer for this component instance. Note this method should NOT return null

Specified by:

getFamily in class UIComponent

Returns:

the component family (not null).

isImmediate

public boolean isImmediate()

The immediate flag.

Specified by:

isImmediate in interface ActionSource

Returns:

true if immediate, false otherwise.

setImmediate

public void setImmediate(boolean immediate)

Description copied from interface: ActionSource

Set the "immediate execution" flag for this UIComponent.

Specified by:

setImmediate in interface ActionSource

Parameters:

immediate - The new immediate execution flag

getValue

public Object getValue()

Returns the value property of the UICommand. This is most often rendered as a label.

Returns:

The object representing the value of this component.

setValue

public void setValue(Object value)

Sets the value property of the UICommand. This is most often rendered as a label.

Parameters:

value - the new value

getActionExpression

public MethodExpression getActionExpression()

Description copied from interface: ActionSource2

Return the MethodExpression pointing at the application action to be invoked, if this UIComponent is activated by the user, during the Apply Request Values or Invoke Application phase of the request processing lifecycle, depending on the value of the immediate property.

Note that it's possible that the returned MethodExpression is just a wrapper around a MethodBinding instance whith was set by a call to ActionSource.setAction(jakarta.faces.el.MethodBinding). This makes it possible for the default ActionListener to continue to work properly with older components.

Specified by:

getActionExpression in interface ActionSource2

Returns:

the action expression.

setActionExpression

public void setActionExpression(MethodExpression actionExpression)

Description copied from interface: ActionSource2

Set the MethodExpression pointing at the appication action to be invoked, if this UIComponent is activated by the user, during the Apply Request Values or Invoke Application phase of the request processing lifecycle, depending on the value of the immediate property.

Any method referenced by such an expression must be public, with a return type of String, and accept no parameters.

Specified by:

setActionExpression in interface ActionSource2

Parameters:

actionExpression - The new method expression

addActionListener

public void addActionListener(ActionListener listener)

Description copied from interface: ActionSource

Add a new ActionListener to the set of listeners interested in being notified when ActionEvents occur.

Specified by:

addActionListener in interface ActionSource

Parameters:

listener - The ActionListener to be added

Throws:

NullPointerException - if listener is null

getActionListeners

public ActionListener[] getActionListeners()

Description copied from interface: ActionSource

Return the set of registered ActionListeners for this ActionSource instance. If there are no registered listeners, a zero-length array is returned.

Specified by:

getActionListeners in interface ActionSource

Returns:

the action listeners, or a zero-length array.

removeActionListener

public void removeActionListener(ActionListener listener)

Description copied from interface: ActionSource

Remove an existing ActionListener (if any) from the set of listeners interested in being notified when ActionEvents occur.

Specified by:

removeActionListener in interface ActionSource

Parameters:

listener - The ActionListener to be removed

Throws:

NullPointerException - if listener is null

broadcast

public void broadcast(FacesEvent event)
               throws AbortProcessingException

In addition to to the default UIComponent.broadcast(jakarta.faces.event.FacesEvent) processing, pass the ActionEvent being broadcast to the method referenced by actionListener (if any), and to the default ActionListener registered on the Application.

Overrides:

broadcast in class UIComponentBase

Parameters:

event - FacesEvent to be broadcast

Throws:

AbortProcessingException - Signal the Jakarta Server Faces implementation that no further processing on the current event should be performed

IllegalArgumentException - if the implementation class of this FacesEvent is not supported by this component

NullPointerException - if event is null

queueEvent

public void queueEvent(FacesEvent event)

Intercept queueEvent and take the following action. If the event is an ActionEvent, obtain the UIComponent instance from the event. If the component is an ActionSource obtain the value of its "immediate" property. If it is true, mark the phaseId for the event to be PhaseId.APPLY_REQUEST_VALUES otherwise, mark the phaseId to be PhaseId.INVOKE_APPLICATION. The event must be passed on to super.queueEvent() before returning from this method.

Overrides:

queueEvent in class UIComponentBase

Parameters:

event - FacesEvent to be queued

getAction

@Deprecated
public MethodBinding getAction()

Deprecated.

This has been replaced by getActionExpression().

If the implementing class also implements ActionSource2, the implementation of this method must call through to ActionSource2.getActionExpression() and examine the result. If the result came from a previous call to ActionSource.setAction(jakarta.faces.el.MethodBinding), extract the MethodBinding from it and return it. Otherwise, wrap the returned MethodExpression in a MethodBinding implementation, and return it.

If the implementing class does not implement ActionSource2, return the MethodBindingpointing at the application action to be invoked, if this UIComponent is activated by the user, during the Apply Request Values or Invoke Application phase of the request processing lifecycle, depending on the value of the immediate property.

Specified by:

getAction in interface ActionSource

Returns:

the action.

setAction

@Deprecated
public void setAction(MethodBinding action)

Deprecated.

This has been replaced by setActionExpression(jakarta.el.MethodExpression).

If the implementing class also implements ActionSource2, the implementation of this method must wrap the argument action in a class that implements MethodExpression and call through to ActionSource2.setActionExpression(jakarta.el.MethodExpression), passing the wrapped action.

If the implementing class does not implement ActionSource2, set the MethodBinding pointing at the appication action to be invoked, if this UIComponent is activated by the user, during the Apply Request Values or Invoke Application phase of the request processing lifecycle, depending on the value of the immediate property.

Any method referenced by such an expression must be public, with a return type of String, and accept no parameters.

Specified by:

setAction in interface ActionSource

Parameters:

action - The new MethodBinding expression

getActionListener

@Deprecated
public MethodBinding getActionListener()

Deprecated.

Use getActionListeners() instead.

If ActionSource.setActionListener(jakarta.faces.el.MethodBinding) was not previously called for this instance, this method must return null. If it was called, this method must return the exact MethodBinding instance that was passed to ActionSource.setActionListener(jakarta.faces.el.MethodBinding).

The method to be invoked, if this UIComponent is activated by the user, will be called during the Apply Request Values or Invoke Application phase of the request processing lifecycle, depending upon the value of the immediate property.

Specified by:

getActionListener in interface ActionSource

Returns:

the action listener.

setActionListener

@Deprecated
public void setActionListener(MethodBinding actionListener)

Deprecated.

This has been replaced by addActionListener(jakarta.faces.event.ActionListener).

Wrap the argument actionListener in an implementation of ActionListener and store it in the internal data structure that backs the ActionSource.getActionListeners() method, taking care to over-write any instance that was stored by a previous call to setActionListener.

Any method referenced by such an expression must be public, with a return type of void, and accept a single parameter of type ActionEvent.

Specified by:

setActionListener in interface ActionSource

Parameters:

actionListener - The new method binding expression