org.apache.tapestry.link
Class AbstractLinkComponent

java.lang.Object
  org.apache.tapestry.spec.BaseLocatable
      org.apache.tapestry.AbstractComponent
          org.apache.tapestry.link.AbstractLinkComponent

All Implemented Interfaces:

ILinkComponent, IComponent, ILocatable, ILocationHolder, IRender

Direct Known Subclasses:

ActionLink, DirectLink, ExternalLink, GenericLink, PageLink, ServiceLink

public abstract class AbstractLinkComponent
extends AbstractComponent
implements ILinkComponent

Base class for implementations of ILinkComponent. Includes a disabled attribute (that should be bound to a disabled parameter), an anchor attribute, and a renderer attribute (that should be bound to a renderer parameter). A default, shared instance of DefaultLinkRenderer is used when no specific renderer is provided.

Version:

$Id: AbstractLinkComponent.java 243791 2004-02-19 17:38:13Z hlship $

Author:

Howard Lewis Ship

Constructor Summary

AbstractLinkComponent()

Method Summary

void	addEventHandler(LinkEventType eventType, String functionName) Adds an event handler (typically, from a wrapped component such as a Rollover).
protected void	cleanupAfterRender(IRequestCycle cycle) Invoked by AbstractComponent.render(IMarkupWriter, IRequestCycle) after the component renders, to clear any parameters back to null (or 0, or false, or whatever the correct default is).
protected void	finishLoad() Sets the renderer parameter property to its default value DefaultLinkRenderer.SHARED_INSTANCE.
abstract String	getAnchor() Returns the anchor defined for this link, or null for no anchor.
ILink	getLink(IRequestCycle cycle) Invoked by the ILinkRenderer (if the link is not disabled) to provide a EngineServiceLink that the renderer can convert into a URL.
protected ILink	getLink(IRequestCycle cycle, String serviceName, Object[] serviceParameters) Utility method for subclasses; Gets the named service from the engine and invokes IEngineService.getLink(IRequestCycle, org.apache.tapestry.IComponent, Object[]) on it.
abstract ILinkRenderer	getRenderer()
abstract boolean	isDisabled() Returns whether this service link component is enabled or disabled.
void	renderAdditionalAttributes(IMarkupWriter writer, IRequestCycle cycle) Invoked (by the ILinkRenderer) to make the link render any additional attributes.
protected void	renderComponent(IMarkupWriter writer, IRequestCycle cycle) Renders the link by delegating to an instance of ILinkRenderer.
abstract void	setRenderer(ILinkRenderer renderer)
protected String	writeEventHandler(IMarkupWriter writer, Body body, String name, String attributeName, Object value)
protected void	writeEventHandlers(IMarkupWriter writer, IRequestCycle cycle)

Methods inherited from class org.apache.tapestry.AbstractComponent

addAsset, addBody, addComponent, finishLoad, fireObservedChange, fireObservedChange, fireObservedChange, fireObservedChange, fireObservedChange, fireObservedChange, fireObservedChange, fireObservedChange, fireObservedChange, format, format, format, format, formatString, formatString, formatString, formatString, generateAttributes, getAsset, getAssets, getBeans, getBinding, getBindingNames, getBindings, getBody, getBodyCount, getChangeObserver, getComponent, getComponents, getContainer, getExtendedId, getId, getIdPath, getListeners, getMessage, getMessages, getNamespace, getPage, getProperty, getSpecification, getString, pageEndRender, prepareForRender, render, renderBody, renderInformalParameters, setBinding, setContainer, setId, setNamespace, setPage, setProperty, setSpecification, toString

Methods inherited from class org.apache.tapestry.spec.BaseLocatable

getLocation, setLocation

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.apache.tapestry.IComponent

addAsset, addBody, addComponent, finishLoad, getAsset, getAssets, getBinding, getBindingNames, getBindings, getComponent, getComponents, getContainer, getExtendedId, getId, getIdPath, getMessage, getMessages, getNamespace, getPage, getProperty, getSpecification, getString, renderBody, setBinding, setContainer, setId, setNamespace, setPage, setProperty, setSpecification

Methods inherited from interface org.apache.tapestry.IRender

render

Methods inherited from interface org.apache.tapestry.ILocationHolder

setLocation

Methods inherited from interface org.apache.tapestry.ILocatable

getLocation

Constructor Detail

AbstractLinkComponent

public AbstractLinkComponent()

Method Detail

isDisabled

public abstract boolean isDisabled()

Description copied from interface: ILinkComponent

Returns whether this service link component is enabled or disabled.

Specified by:

isDisabled in interface ILinkComponent

addEventHandler

public void addEventHandler(LinkEventType eventType,
                            String functionName)

Adds an event handler (typically, from a wrapped component such as a Rollover).

Specified by:

addEventHandler in interface ILinkComponent

renderComponent

protected void renderComponent(IMarkupWriter writer,
                               IRequestCycle cycle)

Renders the link by delegating to an instance of ILinkRenderer.

Specified by:

renderComponent in class AbstractComponent

cleanupAfterRender

protected void cleanupAfterRender(IRequestCycle cycle)

Description copied from class: AbstractComponent

Invoked by AbstractComponent.render(IMarkupWriter, IRequestCycle) after the component renders, to clear any parameters back to null (or 0, or false, or whatever the correct default is). Primarily, this is used to ensure that the component doesn't hold onto any objects that could otherwise be garbage collected.

Subclasses may override this implementation, but must also invoke it.

Overrides:

cleanupAfterRender in class AbstractComponent

writeEventHandlers

protected void writeEventHandlers(IMarkupWriter writer,
                                  IRequestCycle cycle)

writeEventHandler

protected String writeEventHandler(IMarkupWriter writer,
                                   Body body,
                                   String name,
                                   String attributeName,
                                   Object value)

getRenderer

public abstract ILinkRenderer getRenderer()

Since:

3.0

setRenderer

public abstract void setRenderer(ILinkRenderer renderer)

renderAdditionalAttributes

public void renderAdditionalAttributes(IMarkupWriter writer,
                                       IRequestCycle cycle)

Description copied from interface: ILinkComponent

Invoked (by the ILinkRenderer) to make the link render any additional attributes. These are informal parameters, plus any attributes related to events. This is only invoked for non-disabled links.

Specified by:

renderAdditionalAttributes in interface ILinkComponent

getLink

protected ILink getLink(IRequestCycle cycle,
                        String serviceName,
                        Object[] serviceParameters)

Utility method for subclasses; Gets the named service from the engine and invokes IEngineService.getLink(IRequestCycle, org.apache.tapestry.IComponent, Object[]) on it.

Since:

3.0

getAnchor

public abstract String getAnchor()

Description copied from interface: ILinkComponent

Returns the anchor defined for this link, or null for no anchor.

Specified by:

getAnchor in interface ILinkComponent

getLink

public ILink getLink(IRequestCycle cycle)

Description copied from interface: ILinkComponent

Invoked by the ILinkRenderer (if the link is not disabled) to provide a EngineServiceLink that the renderer can convert into a URL.

Specified by:

getLink in interface ILinkComponent

finishLoad

protected void finishLoad()

Sets the renderer parameter property to its default value DefaultLinkRenderer.SHARED_INSTANCE.

Overrides:

finishLoad in class AbstractComponent

Since:

3.0