javax.faces.component
Class UIComponentBase

java.lang.Object
  javax.faces.component.UIComponent
      javax.faces.component.UIComponentBase

All Implemented Interfaces:

StateHolder

Direct Known Subclasses:

UIColumn, UICommand, UIData, UIForm, UIGraphic, UINamingContainer, UIOutput, UIPanel, UIViewRoot

@JSFComponent(type="javax.faces.ComponentBase",
              family="javax.faces.ComponentBase",
              desc="base component when all components must inherit",
              tagClass="javax.faces.webapp.UIComponentELTag",
              configExcluded=true)
@JSFJspProperty(name="binding",
                returnType="javax.faces.component.UIComponent",
                longDesc="Identifies a backing bean property (of type UIComponent or appropriate subclass) to bind to this component instance. This value must be an EL expression.",
                desc="backing bean property to bind to this component instance")
public abstract class UIComponentBase
extends UIComponent

Standard implementation of the UIComponent base class; all standard JSF components extend this class.

Disclaimer: The official definition for the behaviour of this class is the JSF 1.1 specification but for legal reasons the specification cannot be replicated here. Any javadoc here therefore describes the current implementation rather than the spec, though this class has been verified as correctly implementing the spec. see Javadoc of JSF Specification for more.

Version:

$Revision: 949071 $ $Date: 2010-05-27 21:22:17 -0500 (Thu, 27 May 2010) $

Author:

Manfred Geiler (latest modification by $Author: lu4242 $)

Field Summary

Fields inherited from class javax.faces.component.UIComponent

bindings

Constructor Summary

UIComponentBase()

Method Summary

protected void	addFacesListener(FacesListener listener)
void	broadcast(FacesEvent event) Invoke any listeners attached to this object which are listening for an event whose type matches the specified event's runtime type.
void	decode(FacesContext context) Check the submitted form parameters for data associated with this component.
void	encodeBegin(FacesContext context)
void	encodeChildren(FacesContext context)
void	encodeEnd(FacesContext context)
UIComponent	findComponent(String expr) Standard method for finding other components by id, inherited by most UIComponent objects.
Map<String,Object>	getAttributes() Get a map through which all the UIComponent's properties, value-bindings and non-property attributes can be read and written.
int	getChildCount() Return the number of direct child components this component has.
List<UIComponent>	getChildren() Return a list of the UIComponent objects which are direct children of this component.
String	getClientId(FacesContext context) Get a string which can be output to the response which uniquely identifies this UIComponent within the current view.
protected FacesContext	getFacesContext()
protected FacesListener[]	getFacesListeners(Class clazz)
UIComponent	getFacet(String name)
int	getFacetCount()
Map<String,UIComponent>	getFacets()
Iterator<UIComponent>	getFacetsAndChildren()
String	getId() Get a string which uniquely identifies this UIComponent within the scope of the nearest ancestor NamingContainer component.
UIComponent	getParent() Returns the parent of the component.
protected Renderer	getRenderer(FacesContext context)
String	getRendererType()
boolean	getRendersChildren() Indicates whether this component or its renderer manages the invocation of the rendering methods of its child components.
ValueBinding	getValueBinding(String name) Deprecated. Replaced by getValueExpression
boolean	invokeOnComponent(FacesContext context, String clientId, ContextCallback callback) invokeOnComponent must be implemented in UIComponentBase too...
boolean	isRendered() A boolean value that indicates whether this component should be rendered.
boolean	isTransient()
void	processDecodes(FacesContext context)
void	processRestoreState(FacesContext context, Object state)
Object	processSaveState(FacesContext context)
void	processUpdates(FacesContext context) This isn't an input component, so just pass on the processUpdates call to child components and facets that might be input components.
void	processValidators(FacesContext context)
void	queueEvent(FacesEvent event)
protected void	removeFacesListener(FacesListener listener)
static Object	restoreAttachedState(FacesContext context, Object stateObj)
void	restoreState(FacesContext context, Object state) Invoked in the "restore view" phase, this initialises this object's members from the values saved previously into the provided state object.
static Object	saveAttachedState(FacesContext context, Object attachedObject) Serializes objects which are "attached" to this component but which are not UIComponent children of it.
Object	saveState(FacesContext context) Invoked after the render phase has completed, this method returns an object which can be passed to the restoreState of some other instance of UIComponentBase to reset that object's state to the same values as this object currently has.
void	setId(String id) Set an identifier for this component which is unique within the scope of the nearest ancestor NamingContainer component.
void	setParent(UIComponent parent) For JSF-framework internal use only.
void	setRendered(boolean rendered)
void	setRendererType(String rendererType)
void	setTransient(boolean transientFlag)
void	setValueBinding(String name, ValueBinding binding) Deprecated. Replaced by setValueExpression

Methods inherited from class javax.faces.component.UIComponent

encodeAll, getContainerClientId, getFamily, getValueExpression, setValueExpression

Methods inherited from class java.lang.Object

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

Constructor Detail

UIComponentBase

public UIComponentBase()

Method Detail

getAttributes

public Map<String,Object> getAttributes()

Get a map through which all the UIComponent's properties, value-bindings and non-property attributes can be read and written.

When writing to the returned map:

• If this component has an explicit property for the specified key then the setter method is called. An IllegalArgumentException is thrown if the property is read-only. If the property is readable then the old value is returned, otherwise null is returned.
• Otherwise the key/value pair is stored in a map associated with the component.

Note that value-bindings are not written by put calls to this map. Writing to the attributes map using a key for which a value-binding exists will just store the value in the attributes map rather than evaluating the binding, effectively "hiding" the value-binding from later attributes.get calls. Setter methods on components commonly do not evaluate a binding of the same name; they just store the provided value directly on the component.

When reading from the returned map:

• If this component has an explicit property for the specified key then the getter method is called. If the property exists, but is read-only (ie only a setter method is defined) then an IllegalArgumentException is thrown.
• If the attribute map associated with the component has an entry with the specified key, then that is returned.
• If this component has a value-binding for the specified key, then the value-binding is evaluated to fetch the value.
• Otherwise, null is returned.

Note that components commonly define getter methods such that they evaluate a value-binding of the same name if there isn't yet a local property.

Assigning values to the map which are not explicit properties on the underlying component can be used to "tunnel" attributes from the JSP tag (or view-specific equivalent) to the associated renderer without modifying the component itself.

Any value-bindings and non-property attributes stored in this map are automatically serialized along with the component when the view is serialized.

Specified by:

getAttributes in class UIComponent

getValueBinding

public ValueBinding getValueBinding(String name)

Deprecated. Replaced by getValueExpression

Get the named value-binding associated with this component.

Value-bindings are stored in a map associated with the component, though there is commonly a property (setter/getter methods) of the same name defined on the component itself which evaluates the value-binding when called.

Specified by:

getValueBinding in class UIComponent

setValueBinding

public void setValueBinding(String name,
                            ValueBinding binding)

Deprecated. Replaced by setValueExpression

Put the provided value-binding into a map of value-bindings associated with this component.

Specified by:

setValueBinding in class UIComponent

getClientId

public String getClientId(FacesContext context)

Get a string which can be output to the response which uniquely identifies this UIComponent within the current view.

The component should have an id attribute already assigned to it; however if the id property is currently null then a unique id is generated and set for this component. This only happens when components are programmatically created without ids, as components created by a ViewHandler should be assigned ids when they are created.

If this component is a descendant of a NamingContainer then the client id is of form "{namingContainerId}:{componentId}". Note that the naming container's id may itself be of compound form if it has an ancestor naming container. Note also that this only applies to naming containers; other UIComponent types in the component's ancestry do not affect the clientId.

Finally the renderer associated with this component is asked to convert the id into a suitable form. This allows escaping of any characters in the clientId which are significant for the markup language generated by that renderer.

Specified by:

getClientId in class UIComponent

getId

@JSFProperty(rtexprvalue=true)
public String getId()

Get a string which uniquely identifies this UIComponent within the scope of the nearest ancestor NamingContainer component. The id is not necessarily unique across all components in the current view.

Specified by:

getId in class UIComponent

invokeOnComponent

public boolean invokeOnComponent(FacesContext context,
                                 String clientId,
                                 ContextCallback callback)
                          throws FacesException

invokeOnComponent must be implemented in UIComponentBase too...

Overrides:

invokeOnComponent in class UIComponent

Parameters:

context - FacesContext for the current request

clientId - the id of the desired UIComponent clazz

callback - Implementation of the ContextCallback to be called

Returns:

has component been found ?

Throws:

FacesException

setId

public void setId(String id)

Set an identifier for this component which is unique within the scope of the nearest ancestor NamingContainer component. The id is not necessarily unique across all components in the current view.

The id must start with an underscore if it is generated by the JSF framework, and must not start with an underscore if it has been specified by the user (eg in a JSP tag).

The first character of the id must be an underscore or letter. Following characters may be letters, digits, underscores or dashes.

Null is allowed as a parameter, and will reset the id to null.

The clientId of this component is reset by this method; see getClientId for more info.

Specified by:

setId in class UIComponent

Throws:

IllegalArgumentException - if the id is not valid.

getParent

public UIComponent getParent()

Description copied from class: UIComponent

Returns the parent of the component. Children can be added to or removed from a component even if this method returns null for the child.

Specified by:

getParent in class UIComponent

setParent

public void setParent(UIComponent parent)

Description copied from class: UIComponent

For JSF-framework internal use only. Don't call this method to add components to the component tree. Use parent.getChildren().add(child) instead.

Specified by:

setParent in class UIComponent

getRendersChildren

public boolean getRendersChildren()

Indicates whether this component or its renderer manages the invocation of the rendering methods of its child components. When this is true:

• This component's encodeBegin method will only be called after all the child components have been created and added to this component.
• This component's encodeChildren method will be called after its encodeBegin method. Components for which this method returns false do not get this method invoked at all.
• No rendering methods will be called automatically on child components; this component is required to invoke the encodeBegin/encodeEnd/etc on them itself.

Specified by:

getRendersChildren in class UIComponent

getChildren

public List<UIComponent> getChildren()

Return a list of the UIComponent objects which are direct children of this component.

The list object returned has some non-standard behaviour:

• The list is type-checked; only UIComponent objects can be added.
• If a component is added to the list with an id which is the same as some other component in the list then an exception is thrown. However multiple components with a null id may be added.
• The component's parent property is set to this component. If the component already had a parent, then the component is first removed from its original parent's child list.

Specified by:

getChildren in class UIComponent

getChildCount

public int getChildCount()

Return the number of direct child components this component has.

Identical to getChildren().size() except that when this component has no children this method will not force an empty list to be created.

Specified by:

getChildCount in class UIComponent

findComponent

public UIComponent findComponent(String expr)

Standard method for finding other components by id, inherited by most UIComponent objects.

The lookup is performed in a manner similar to finding a file in a filesystem; there is a "base" at which to start, and the id can be for something in the "local directory", or can include a relative path. Here, NamingContainer components fill the role of directories, and ":" is the "path separator". Note, however, that although components have a strict parent/child hierarchy, component ids are only prefixed ("namespaced") with the id of their parent when the parent is a NamingContainer.

The base node at which the search starts is determined as follows:

• When expr starts with ':', the search starts with the root component of the tree that this component is in (ie the ancestor whose parent is null).
• Otherwise, if this component is a NamingContainer then the search starts with this component.
• Otherwise, the search starts from the nearest ancestor NamingContainer (or the root component if there is no NamingContainer ancestor).

Specified by:

findComponent in class UIComponent

Parameters:

expr - is of form "id1:id2:id3".

Returns:

UIComponent or null if no component with the specified id is found.

getFacets

public Map<String,UIComponent> getFacets()

Specified by:

getFacets in class UIComponent

getFacet

public UIComponent getFacet(String name)

Specified by:

getFacet in class UIComponent

getFacetsAndChildren

public Iterator<UIComponent> getFacetsAndChildren()

Specified by:

getFacetsAndChildren in class UIComponent

broadcast

public void broadcast(FacesEvent event)
               throws AbortProcessingException

Invoke any listeners attached to this object which are listening for an event whose type matches the specified event's runtime type.

This method does not propagate the event up to parent components, ie listeners attached to parent components don't automatically get called.

If any of the listeners throws AbortProcessingException then that exception will prevent any further listener callbacks from occurring, and the exception propagates out of this method without alteration.

ActionEvent events are typically queued by the renderer associated with this component in its decode method; ValueChangeEvent events by the component's validate method. In either case the event's source property references a component. At some later time the UIViewRoot component iterates over its queued events and invokes the broadcast method on each event's source object.

Specified by:

broadcast in class UIComponent

Parameters:

event - must not be null.

Throws:

AbortProcessingException

decode

public void decode(FacesContext context)

Check the submitted form parameters for data associated with this component. This default implementation delegates to this component's renderer if there is one, and otherwise ignores the call.

Specified by:

decode in class UIComponent

encodeBegin

public void encodeBegin(FacesContext context)
                 throws IOException

Specified by:

encodeBegin in class UIComponent

Throws:

IOException

encodeChildren

public void encodeChildren(FacesContext context)
                    throws IOException

Specified by:

encodeChildren in class UIComponent

Throws:

IOException

encodeEnd

public void encodeEnd(FacesContext context)
               throws IOException

Specified by:

encodeEnd in class UIComponent

Throws:

IOException

addFacesListener

protected void addFacesListener(FacesListener listener)

Specified by:

addFacesListener in class UIComponent

getFacesListeners

protected FacesListener[] getFacesListeners(Class clazz)

Specified by:

getFacesListeners in class UIComponent

removeFacesListener

protected void removeFacesListener(FacesListener listener)

Specified by:

removeFacesListener in class UIComponent

queueEvent

public void queueEvent(FacesEvent event)

Specified by:

queueEvent in class UIComponent

processDecodes

public void processDecodes(FacesContext context)

Specified by:

processDecodes in class UIComponent

processValidators

public void processValidators(FacesContext context)

Specified by:

processValidators in class UIComponent

processUpdates

public void processUpdates(FacesContext context)

This isn't an input component, so just pass on the processUpdates call to child components and facets that might be input components.

Components that were never rendered can't possibly be receiving update data (no corresponding fields were ever put into the response) so if this component is not rendered then this method does not invoke processUpdates on its children.

Specified by:

processUpdates in class UIComponent

processSaveState

public Object processSaveState(FacesContext context)

Specified by:

processSaveState in class UIComponent

processRestoreState

public void processRestoreState(FacesContext context,
                                Object state)

Specified by:

processRestoreState in class UIComponent

getFacesContext

protected FacesContext getFacesContext()

Specified by:

getFacesContext in class UIComponent

getRenderer

protected Renderer getRenderer(FacesContext context)

Specified by:

getRenderer in class UIComponent

isTransient

@JSFProperty(literalOnly=true,
             istransient=true,
             tagExcluded=true)
public boolean isTransient()

setTransient

public void setTransient(boolean transientFlag)

saveAttachedState

public static Object saveAttachedState(FacesContext context,
                                       Object attachedObject)

Serializes objects which are "attached" to this component but which are not UIComponent children of it. Examples are validator and listener objects. To be precise, it returns an object which implements java.io.Serializable, and which when serialized will persist the state of the provided object.

If the attachedObject is a List then every object in the list is saved via a call to this method, and the returned wrapper object contains a List object.

If the object implements StateHolder then the object's saveState is called immediately, and a wrapper is returned which contains both this saved state and the original class name. However in the case where the StateHolder.isTransient method returns true, null is returned instead.

If the object implements java.io.Serializable then the object is simply returned immediately; standard java serialization will later be used to store this object.

In all other cases, a wrapper is returned which simply stores the type of the provided object. When deserialized, a default instance of that type will be recreated.

restoreAttachedState

public static Object restoreAttachedState(FacesContext context,
                                          Object stateObj)
                                   throws IllegalStateException

Throws:

IllegalStateException

saveState

public Object saveState(FacesContext context)

Invoked after the render phase has completed, this method returns an object which can be passed to the restoreState of some other instance of UIComponentBase to reset that object's state to the same values as this object currently has.

restoreState

public void restoreState(FacesContext context,
                         Object state)

Invoked in the "restore view" phase, this initialises this object's members from the values saved previously into the provided state object.

Parameters:

state - is an object previously returned by the saveState method of this class.

setRendered

public void setRendered(boolean rendered)

Specified by:

setRendered in class UIComponent

isRendered

@JSFProperty
public boolean isRendered()

A boolean value that indicates whether this component should be rendered. Default value: true.

Specified by:

isRendered in class UIComponent

setRendererType

public void setRendererType(String rendererType)

Specified by:

setRendererType in class UIComponent

getRendererType

public String getRendererType()

Specified by:

getRendererType in class UIComponent

getFacetCount

public int getFacetCount()

Overrides:

getFacetCount in class UIComponent

Since:

1.2