org.apache.cocoon.generation
Class VelocityGenerator

java.lang.Object
  org.apache.avalon.framework.logger.AbstractLogEnabled
      org.apache.cocoon.xml.AbstractXMLProducer
          org.apache.cocoon.generation.AbstractGenerator
              org.apache.cocoon.generation.ServiceableGenerator
                  org.apache.cocoon.generation.VelocityGenerator

All Implemented Interfaces:

Poolable, Recyclable, Disposable, Initializable, Component, Configurable, LogEnabled, Serviceable, Generator, SitemapModelComponent, XMLProducer, org.apache.velocity.runtime.log.LogSystem

public class VelocityGenerator
extends ServiceableGenerator
implements Initializable, Configurable, org.apache.velocity.runtime.log.LogSystem

Cocoon Generator that produces dynamic XML SAX events from a Velocity template file.

If called from a Flowscript, the immediate properties of the context object from the Flowscript are available in the Velocity context. In that case, the current Web Continuation from the Flowscript is also available as a variable named continuation. You would typically access its id:

    <form action="$continuation.id">
 

You can also reach previous continuations by using the getContinuation() function:

     <form action="$continuation.getContinuation(1).id}" >
 

In addition the following implicit objects are always available in the Velocity context:

request (org.apache.cocoon.environment.Request)

The Cocoon current request

response (org.apache.cocoon.environment.Response)

The Cocoon response associated with the current request

session (org.apache.cocoon.environment.Session)

The Cocoon session associated with the current request

context (org.apache.cocoon.environment.Context)

The Cocoon context associated with the current request

parameters (org.apache.avalon.framework.parameters.Parameters)

Any parameters passed to the generator in the pipeline

Sitemap Configuration

Attributes:

usecache (optional; default: 'false')

set to 'true' to enable template caching on the 'cocoon' resource loader

checkInterval (optional; default: '0')

This is the number of seconds between modification checks when caching is turned on. When this is an integer > 0, this represents the number of seconds between checks to see if the template was modified. If the template has been modified since last check, then it is reloaded and reparsed. Otherwise nothing is done. When <= 0, no modification checks will take place, and assuming that the property cache (above) is true, once a template is loaded and parsed the first time it is used, it will not be checked or reloaded after that until the application or servlet engine is restarted.

Child Elements:

<property name="propertyName" value="propertyValue"/> (optional; 0..n)

An additional property to pass along to the Velocity template engine during initialization

<resource-loader name="loaderName" class="javaClassName" > (optional; 0..n; children: property*)

The default configuration uses the 'cocoon' resource loader which resolves resources via the Cocoon SourceResolver. Additional resource loaders can be added with this configuration element. Configuration properties for the resource loader can be specified by adding a child property element of the resource-loader element. The prefix '<name>.resource.loader.' is automatically added to the property name.

Version:

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

Nested Class Summary

static class	VelocityGenerator.ChainedContext Velocity context implementation specific to the Servlet environment.
static class	VelocityGenerator.JSIntrospector Velocity Introspector that supports Rhino JavaScript objects as well as Java Objects
static class	VelocityGenerator.TemplateLoader Velocity ResourceLoader implementation to load template resources using Cocoon's SourceResolver.

Field Summary

Fields inherited from class org.apache.cocoon.generation.ServiceableGenerator

manager

Fields inherited from class org.apache.cocoon.generation.AbstractGenerator

objectModel, parameters, resolver, source

Fields inherited from class org.apache.cocoon.xml.AbstractXMLProducer

contentHandler, EMPTY_CONTENT_HANDLER, lexicalHandler, xmlConsumer

Fields inherited from interface org.apache.velocity.runtime.log.LogSystem

DEBUG_ID, DEBUG_ON, ERROR_ID, INFO_ID, WARN_ID

Fields inherited from interface org.apache.cocoon.generation.Generator

ROLE

Constructor Summary

VelocityGenerator()

Method Summary

void	configure(Configuration configuration) Read any additional objects to export to the Velocity context from the configuration.
void	generate() Generate XML data using Velocity template.
void	init(org.apache.velocity.runtime.RuntimeServices rs) This implementation does nothing.
void	initialize()
void	logVelocityMessage(int level, String message) Pass along Velocity log messages to our configured logger.
void	recycle() Free up the VelocityContext associated with the pipeline, and release any Source objects resolved by the resource loader.
void	setup(SourceResolver resolver, Map objectModel, String src, Parameters params) Set the SourceResolver, object model Map, the source and sitemap Parameters used to process the request.

Methods inherited from class org.apache.cocoon.generation.ServiceableGenerator

dispose, service

Methods inherited from class org.apache.cocoon.xml.AbstractXMLProducer

setConsumer, setContentHandler, setLexicalHandler

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.xml.XMLProducer

setConsumer

Constructor Detail

VelocityGenerator

public VelocityGenerator()

Method Detail

configure

public void configure(Configuration configuration)
               throws ConfigurationException

Read any additional objects to export to the Velocity context from the configuration.

Specified by:

configure in interface Configurable

Parameters:

configuration - the class configurations.

Throws:

ConfigurationException

See Also:

Configurable.configure(Configuration)

initialize

public void initialize()
                throws Exception

Specified by:

initialize in interface Initializable

Throws:

Exception

See Also:

Initializable.initialize()

setup

public void setup(SourceResolver resolver,
                  Map objectModel,
                  String src,
                  Parameters params)
           throws ProcessingException,
                  SAXException,
                  IOException

Description copied from class: AbstractGenerator

Set the SourceResolver, object model Map, the source and sitemap Parameters used to process the request.

Specified by:

setup in interface SitemapModelComponent

Overrides:

setup in class AbstractGenerator

Throws:

ProcessingException

SAXException

IOException

See Also:

SitemapModelComponent.setup(SourceResolver, Map, String, Parameters)

recycle

public void recycle()

Free up the VelocityContext associated with the pipeline, and release any Source objects resolved by the resource loader.

Specified by:

recycle in interface Recyclable

Overrides:

recycle in class AbstractGenerator

See Also:

Recyclable.recycle()

generate

public void generate()
              throws IOException,
                     SAXException,
                     ProcessingException

Generate XML data using Velocity template.

Specified by:

generate in interface Generator

Throws:

IOException

SAXException

ProcessingException

See Also:

Generator.generate()

init

public void init(org.apache.velocity.runtime.RuntimeServices rs)
          throws Exception

This implementation does nothing.

Specified by:

init in interface org.apache.velocity.runtime.log.LogSystem

Throws:

Exception

See Also:

LogSystem.init(RuntimeServices)

logVelocityMessage

public void logVelocityMessage(int level,
                               String message)

Pass along Velocity log messages to our configured logger.

Specified by:

logVelocityMessage in interface org.apache.velocity.runtime.log.LogSystem

See Also:

LogSystem.logVelocityMessage(int, String)