Package org.zkoss.zk.ui.sys

Class StubComponent

java.lang.Object

org.zkoss.zk.ui.AbstractComponent

org.zkoss.zk.ui.sys.StubComponent

All Implemented Interfaces:

Serializable, Cloneable, Component, Scope, ComponentCtrl

Direct Known Subclasses:

StubsComponent

public class StubComponent
extends AbstractComponent

A stub component is a 'degenerated' component that does not maintain the states at the server. Rather, the states are maintained at the peer widget (running at the client).

Application isn't really aware the existence of a stub component. Rather, it is used by ZK Loader to minimize the footprint, if it found a component doesn't have to maintain the states at the server after rendered. For example, HtmlNativeComponent and stub-only components will degenerate to StubComponent or StubsComponent after rendered. Refer Component.setStubonly(java.lang.String) for details about a stub-only component.

A component that wants to degenerate to a stub component usually invoke replace(org.zkoss.zk.ui.Component, boolean, boolean, boolean) after AbstractComponent.redraw(java.io.Writer) is called.

Since:

6.0.0

Author:

tomyeh

See Also:

• Serialized Form

Nested Class Summary

Nested classes/interfaces inherited from class org.zkoss.zk.ui.AbstractComponent

AbstractComponent.Children, AbstractComponent.ForwardInfo, AbstractComponent.TargetInfo

Field Summary

Fields inherited from interface org.zkoss.zk.ui.Component

APPLICATION_SCOPE, COMPONENT_SCOPE, DESKTOP_SCOPE, PAGE_SCOPE, REQUEST_SCOPE, SESSION_SCOPE, SPACE_SCOPE

Fields inherited from interface org.zkoss.zk.ui.sys.ComponentCtrl

AFTER_CHILD_ADDED, AFTER_CHILD_REMOVED, AFTER_CLONED, AFTER_PAGE_ATTACHED, AFTER_PAGE_DETACHED, AFTER_PARENT_CHANGED, CE_BUSY_IGNORE, CE_DUPLICATE_IGNORE, CE_IMPORTANT, CE_NON_DEFERRABLE, CE_REPEAT_IGNORE

Constructor Summary

Constructors

Constructor	Description
StubComponent()

Method Summary

Modifier and Type	Method	Description
String	getId(String uuid)	Returns ID of the given UUID, or null if not found or no ID assigned.
String	getWidgetClass()	Returns the widget class, "#stub".
void	replace(Component comp, boolean bFellow, boolean bListener, boolean bChildren)	Replace the specified component with this component in the component tree.
void	service(AuRequest request, boolean everError)	Handles an AU request.
void	service(Event event, Scope scope)	Handles an event.

Methods inherited from class org.zkoss.zk.ui.AbstractComponent

addAnnotation, addCallback, addClientEvent, addEventHandler, addEventListener, addEventListener, addForward, addForward, addForward, addForward, addMoved, addRedrawCallback, addScopeListener, addShadowRoot, addShadowRootBefore, addSharedEventHandlerMap, appendChild, applyProperties, beforeChildAdded, beforeChildRemoved, beforeParentChanged, clone, destroyIndexCacheMap, detach, didActivate, didActivate, didDeserialize, didDeserialize, disableBindingAnnotation, disableClientUpdate, disableHostChanged, enableBindingAnnotation, enableHostChanged, getAnnotatedProperties, getAnnotatedPropertiesBy, getAnnotation, getAnnotations, getAnnotations, getAttribute, getAttribute, getAttribute, getAttributeOrFellow, getAttributes, getAttributes, getAuService, getAutag, getCallback, getChildren, getClientAttribute, getClientDataAttribute, getClientEvents, getDefaultMold, getDefinition, getDesktop, getEventHandler, getEventHandlerNames, getEventListenerMap, getEventListeners, getExtraCtrl, getFellow, getFellow, getFellowIfAny, getFellowIfAny, getFellows, getFirstChild, getForwards, getId, getIndexCacheMap, getLastChild, getMold, getNextSibling, getPage, getParent, getPreviousSibling, getPropertyAccess, getRedrawCallback, getRoot, getShadowFellowIfAny, getShadowRoots, getShadowVariable, getShadowVariable, getShadowVariable0, getSpaceOwner, getSpecialRendererOutput, getStubonly, getStubonlyDescendants, getSubBindingAnnotationCount, getTemplate, getTemplateNames, getUuid, getWidgetAttributeNames, getWidgetListener, getWidgetListenerNames, getWidgetOverride, getWidgetOverrideNames, hasAttribute, hasAttribute, hasAttribute, hasAttributeOrFellow, hasBindingAnnotation, hasFellow, hasFellow, hasSubBindingAnnotation, initIndexCacheMap, insertBefore, invalidate, isChildable, isDisabledHostChanged, isInitialized, isInvalidated, isListenerAvailable, isVisible, onChildAdded, onChildRemoved, onPageAttached, onPageDetached, onParentChanged, onWrongValue, query, queryAll, redraw, redrawChildren, removeAttribute, removeAttribute, removeAttribute, removeCallback, removeChild, removeEventListener, removeForward, removeForward, removeRedrawCallback, removeScopeListener, removeShadowRoot, render, render, render, renderProperties, renderPropertiesOnly, response, response, response, sessionDidActivate, sessionWillPassivate, setAttribute, setAttribute, setAttribute, setAuService, setAutag, setClientAttribute, setClientDataAttribute, setDefinition, setDefinition, setId, setMold, setPage, setPageBefore, setParent, setStubonly, setStubonly, setStubonlyDescendants, setSubBindingAnnotationCount, setTemplate, setVisible, setVisibleDirectly, setWidgetClass, setWidgetListener, setWidgetOverride, smartUpdate, smartUpdate, smartUpdate, smartUpdate, smartUpdate, smartUpdate, smartUpdate, smartUpdate, smartUpdate, smartUpdateWidgetListener, smartUpdateWidgetOverride, toString, updateByClient, updateSubBindingAnnotationCount, willPassivate, willPassivate, willSerialize, willSerialize

Methods inherited from class java.lang.Object

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

Constructor Details

StubComponent

public StubComponent()

Method Details

getId

public String getId(String uuid)

Returns ID of the given UUID, or null if not found or no ID assigned. It assumes the given UUID belonged to one of the component being merged into this component.

Notice that it searches all descendants of this component.

replace

public void replace(Component comp,
 boolean bFellow,
 boolean bListener,
 boolean bChildren)

Replace the specified component with this component in the component tree. In other words, the parent of the given component will become the parent of this components, so are siblings and children. Furthermore, comp will be detached at the end.

Notice that the replacement won't change anything at the client. A stub component assumes there is a full-functional widget running at the client to handle everything.

Overrides:

replace in class AbstractComponent

Parameters:

comp - the component. In this implementation it supports only derived classes of AbstractComponent.

bFellow - whether to add this component to the map of fellows if it is assigned with an ID. If false, the component (comp) cannot be retrieved back even with an ID.

bListener - whether to retain the event listeners and handlers. If true, the event listeners and handlers, if any, will be registered to this stub component. In other words, the event will be processed. However, it is a stub component, rather than the original one. I means the event is the most generic format: an instance of Event (rather than MouseEvent or others).

bChildren - whether to have the children of the given component.
If false, this component won't have any children, and all UUID of children reference back to this component.
If true, the given component's children will belong to this component.

Throws:

IllegalStateException - if this component has a parent, sibling or child.

getWidgetClass

public String getWidgetClass()

Returns the widget class, "#stub".

Specified by:

getWidgetClass in interface Component

Overrides:

getWidgetClass in class AbstractComponent

See Also:

• Component.setWidgetClass(java.lang.String)

service

public void service(AuRequest request,
 boolean everError)

Description copied from class: AbstractComponent

Handles an AU request. It is invoked internally.

Default: it handles echo and setAttr, and it converts other request to an event (by Event.getEvent(org.zkoss.zk.au.AuRequest)) and then posts the event (by Events.postEvent(org.zkoss.zk.ui.event.Event)).

Application developer can plug the custom service to handle the AU request by AbstractComponent.setAuService(org.zkoss.zk.au.AuService).

Specified by:

service in interface ComponentCtrl

Overrides:

service in class AbstractComponent

everError - whether any error ever occurred before processing this request.

See Also:

• AbstractComponent.setAuService(org.zkoss.zk.au.AuService)

service

public void service(Event event,
 Scope scope)
             throws Exception

Description copied from interface: ComponentCtrl

Handles an event. This method will invoke the event handlers registered in a ZUML page, the event listeners registered in Java, and the event handlers declared as part of the component.

Specified by:

service in interface ComponentCtrl

Overrides:

service in class AbstractComponent

Parameters:

event - the event to handle

scope - the scope to evaluate the zscript, if any. (see also Page.interpret(java.lang.String, java.lang.String, org.zkoss.zk.ui.ext.Scope).

Throws:

Exception