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org.apache.cocoon.components.flow
Class AbstractInterpreter

java.lang.Object
  org.apache.avalon.framework.logger.AbstractLogEnabled
      org.apache.cocoon.components.flow.AbstractInterpreter

All Implemented Interfaces:

Disposable, Component, Configurable, Contextualizable, LogEnabled, Serviceable, SingleThreaded, Interpreter

Direct Known Subclasses:

ApplesProcessor, CompilingInterpreter, JavaInterpreter

public abstract class AbstractInterpreter
extends AbstractLogEnabled
implements Component, Serviceable, Contextualizable, Interpreter, SingleThreaded, Configurable, Disposable

Abstract superclass for various scripting languages used by Cocoon for flow control. Defines some useful behavior like the ability to reload script files if they get modified (useful when doing development), and passing the control to Cocoon's sitemap for result page generation.

Flow intrepreters belonging to different sitemaps should be isolated. To achieve this, class implements the SingleThreaded. Since the sitemap engine looks up the flow intepreter once at sitemap build time, this ensures that each sitemap will use a different instance of this class. But that instance will handle all flow calls for a given sitemap, and must therefore be thread safe.

Since:

March 15, 2002

Version:

CVS $Id: AbstractInterpreter.html 1304258 2012-03-23 10:09:27Z ilgrosso $

Author:

Ovidiu Predescu

Nested Class Summary

Nested classes/interfaces inherited from interface org.apache.cocoon.components.flow.Interpreter

Interpreter.Argument

Field Summary

protected Context	avalonContext
protected long	checkTime Interval between two checks for modified script files.
protected Context	context
protected ContinuationsManager	continuationsMgr
protected ServiceManager	manager
protected ArrayList	needResolve List of source locations that need to be resolved.
protected boolean	reloadScripts Whether reloading of scripts should be done.

Fields inherited from interface org.apache.cocoon.components.flow.Interpreter

ROLE

Constructor Summary

AbstractInterpreter()

Method Summary

void	configure(Configuration config)
void	contextualize(Context context)
void	dispose()
void	forwardTo(String uri, Object bizData, WebContinuation continuation, Redirector redirector) Forward the request to a Cocoon pipeline.
String	getInterpreterID() Get the unique ID for this interpreter, which can be used to distinguish user value scopes attached to the session.
void	process(String uri, Object biz, OutputStream out) Call the Cocoon sitemap for the given URI, sending the output of the eventually matched pipeline to the specified outputstream.
void	register(String source) Registers a source file with the interpreter.
void	service(ServiceManager sm) Serviceable
void	setInterpreterID(String interpreterID) Set the unique ID for this interpreter, which can be used to distinguish user value scopes attached to the session.

Methods inherited from class org.apache.avalon.framework.logger.AbstractLogEnabled

enableLogging, getLogger, setupLogger, setupLogger, setupLogger

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.apache.cocoon.components.flow.Interpreter

callFunction, handleContinuation

Field Detail

avalonContext

protected Context avalonContext

needResolve

protected ArrayList needResolve

List of source locations that need to be resolved.

context

protected Context context

manager

protected ServiceManager manager

continuationsMgr

protected ContinuationsManager continuationsMgr

reloadScripts

protected boolean reloadScripts

Whether reloading of scripts should be done. Specified through the "reload-scripts" attribute in flow.xmap.

checkTime

protected long checkTime

Interval between two checks for modified script files. Specified through the "check-time" XML attribute in flow.xmap.

Constructor Detail

AbstractInterpreter

public AbstractInterpreter()

Method Detail

setInterpreterID

public void setInterpreterID(String interpreterID)

Set the unique ID for this interpreter, which can be used to distinguish user value scopes attached to the session.

Specified by:

setInterpreterID in interface Interpreter

getInterpreterID

public String getInterpreterID()

Get the unique ID for this interpreter, which can be used to distinguish user value scopes attached to the session.

Specified by:

getInterpreterID in interface Interpreter

Returns:

a unique ID for this interpreter

configure

public void configure(Configuration config)
               throws ConfigurationException

Specified by:

configure in interface Configurable

Throws:

ConfigurationException

service

public void service(ServiceManager sm)
             throws ServiceException

Serviceable

Specified by:

service in interface Serviceable

Throws:

ServiceException

contextualize

public void contextualize(Context context)
                   throws ContextException

Specified by:

contextualize in interface Contextualizable

Throws:

ContextException

dispose

public void dispose()

Specified by:

dispose in interface Disposable

register

public void register(String source)

Registers a source file with the interpreter. Using this method an implementation keeps track of all the script files which are compiled. This allows them to reload the script files which get modified on the file system.

The parsing/compilation of a script file by an interpreter happens in two phases. In the first phase the file's location is registered in the needResolve array.

The second is possible only when a Cocoon Environment is passed to the Interpreter. This allows the file location to be resolved using Cocoon's SourceFactory class.

Once a file's location can be resolved, it is removed from the needResolve array and placed in the scripts hash table. The key in this hash table is the file location string, and the value is a DelayedRefreshSourceWrapper instance which keeps track of when the file needs to re-read.

Parameters:

source - the location of the script

See Also:

Environment, DelayedRefreshSourceWrapper

process

public void process(String uri,
                    Object biz,
                    OutputStream out)
             throws Exception

Call the Cocoon sitemap for the given URI, sending the output of the eventually matched pipeline to the specified outputstream.

Parameters:

uri - The URI for which the request should be generated.

biz - Extra data associated with the subrequest.

out - An OutputStream where the output should be written to.

Throws:

Exception - If an error occurs.

forwardTo

public void forwardTo(String uri,
                      Object bizData,
                      WebContinuation continuation,
                      Redirector redirector)
               throws Exception

Description copied from interface: Interpreter

Forward the request to a Cocoon pipeline.

Specified by:

forwardTo in interface Interpreter

Parameters:

uri - a String, the URI of the forwarded request

bizData - an Object, the business data object to be made available to the forwarded pipeline

continuation - a WebContinuation, the continuation to be called to resume the processing

redirector - a Redirector used to call views

Throws:

Exception - if an error occurs