org.apache.myfaces.orchestra.lib.jsf
Class _FacesContextWrapper

java.lang.Object
  extended by FacesContext
      extended by org.apache.myfaces.orchestra.lib.jsf._FacesContextWrapper

public class _FacesContextWrapper
extends FacesContext

Convenient class to wrap the current FacesContext.

A class of this name is provided in JSF1.2, but not in JSF1.1.

Any methods that do not actually need to be overridden are declared final in order to improve performance (helps the JVM to optimise away the call).

Note that whether a newly-created instance immediately becomes the object that is returned by FacesContext.getCurrentInstance() depends upon the value of the "install" parameter for the constructor method.

This class is copied from the code in MyFaces Core Impl 1.2.x, but modified to be compatible with JSF1.1.

Note that this class must be public in order to support custom FacesContextFactory classes in other libraries that also wrap this instance, then use reflection to invoke methods on this object. In this case, an IllegalAccessException would occur if this class was package-scoped. However this class is NOT intended to be part of the public Orchestra API, and may change at any time.

Since:
1.1
Version:
$Revision: 672906 $ $Date: 2008-06-30 15:45:16 -0500 (Mon, 30 Jun 2008) $
Author:
Manfred Geiler (latest modification by $Author: skitching $), Anton Koinov

Constructor Summary
_FacesContextWrapper(FacesContext facesContext, boolean install)
          The install parameter controls whether this object will be configured as the object returned from calls to FacesContext.getCurrentInstance() or not.
 
Method Summary
 void addMessage(java.lang.String clientId, FacesMessage message)
           
 Application getApplication()
           
 java.util.Iterator getClientIdsWithMessages()
           
 ELContext getELContext()
          Implement getELContext by delegating call to another instance.
 ExternalContext getExternalContext()
           
 FacesMessage.Severity getMaximumSeverity()
           
 java.util.Iterator getMessages()
           
 java.util.Iterator getMessages(java.lang.String clientId)
           
 RenderKit getRenderKit()
           
 boolean getRenderResponse()
           
 boolean getResponseComplete()
           
 ResponseStream getResponseStream()
           
 ResponseWriter getResponseWriter()
           
 UIViewRoot getViewRoot()
           
 void release()
           
 void renderResponse()
           
 void responseComplete()
           
 void setResponseStream(ResponseStream responsestream)
           
 void setResponseWriter(ResponseWriter responsewriter)
           
 void setViewRoot(UIViewRoot viewRoot)
           
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 

Constructor Detail

_FacesContextWrapper

public _FacesContextWrapper(FacesContext facesContext,
                            boolean install)
The install parameter controls whether this object will be configured as the object returned from calls to FacesContext.getCurrentInstance() or not.

When only overriding the release() method, then install=false is ok as that is called directly by the FacesServlet on the instance returned by the FacesContextFactory. However all other methods are invoked on the object that is returned from FacesContext.getCurrentInstance, so install=true is needed in order for any other method overrides to have any effect.

IMPORTANT: install=true should not be used until MYFACES-1820 is fixed.

Method Detail

release

public void release()

getApplication

public final Application getApplication()

getClientIdsWithMessages

public final java.util.Iterator getClientIdsWithMessages()

getExternalContext

public final ExternalContext getExternalContext()

getMaximumSeverity

public final FacesMessage.Severity getMaximumSeverity()

getMessages

public final java.util.Iterator getMessages()

getMessages

public final java.util.Iterator getMessages(java.lang.String clientId)

getRenderKit

public final RenderKit getRenderKit()

getRenderResponse

public final boolean getRenderResponse()

getResponseComplete

public final boolean getResponseComplete()

setResponseStream

public final void setResponseStream(ResponseStream responsestream)

getResponseStream

public final ResponseStream getResponseStream()

setResponseWriter

public final void setResponseWriter(ResponseWriter responsewriter)

getResponseWriter

public final ResponseWriter getResponseWriter()

setViewRoot

public final void setViewRoot(UIViewRoot viewRoot)

getViewRoot

public final UIViewRoot getViewRoot()

addMessage

public final void addMessage(java.lang.String clientId,
                             FacesMessage message)

renderResponse

public final void renderResponse()

responseComplete

public final void responseComplete()

getELContext

public final ELContext getELContext()
Implement getELContext by delegating call to another instance.

Note that this method was added in JSF1.2. In order for a JSF1.2 implementation to be backwards-compatible with JSF1.1, the base class FacesContext therefore has to automatically do the delegation. Without automatic delegation, any JSF1.1 class that applies the decorator pattern to a FacesContext will just break in JSF1.2; the getELContext method is there (inherited from the base class) but does not correctly delegate.

Unfortunately, due to a design flaw in JSF1.2 it is simply not possible for the base class to delegate; the object to delegate to is not known to the base class! A partial solution that works in most cases is for the base class to delegate to the "core" instance of FacesContext for methods that are not overridden; Sun's RI does this correctly but unfortunately MyFaces 1.2.0-1.2.2 do not. See MYFACES-1820 for details.

The solution *here* is to require that a javax.el implementation is in the classpath even when running JSF1.1. It is then possible for this wrapper to override the method defined in JSF1.2 even when being compiled against the JSF1.1 implementation. It is mildly annoying to have to include javax.el in a JSF environment (ie when it will never be used) but better than the alternatives. Actually, for at least some JVMs, classes needed by a method are not loaded unless that method is actually referenced, so in some cases (including Sun Java 1.4-1.6) the el library *can* be omitted from the classpath with JSF1.1.



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