org.apache.cocoon.generation
Class VelocityGenerator

java.lang.Object
  |
  +--org.apache.avalon.framework.logger.AbstractLoggable
        |
        +--org.apache.cocoon.xml.AbstractXMLProducer
              |
              +--org.apache.cocoon.generation.AbstractGenerator
                    |
                    +--org.apache.cocoon.generation.ComposerGenerator
                          |
                          +--org.apache.cocoon.generation.VelocityGenerator

All Implemented Interfaces:

org.apache.avalon.framework.component.Component, org.apache.avalon.framework.component.Composable, org.apache.avalon.framework.configuration.Configurable, org.apache.avalon.framework.activity.Disposable, Generator, org.apache.avalon.framework.activity.Initializable, org.apache.avalon.framework.logger.Loggable, org.apache.velocity.runtime.log.LogSystem, org.apache.avalon.excalibur.pool.Poolable, org.apache.avalon.excalibur.pool.Recyclable, SitemapModelComponent, XMLProducer

public class VelocityGenerator

extends ComposerGenerator

implements org.apache.avalon.framework.activity.Initializable, org.apache.avalon.framework.configuration.Configurable, org.apache.velocity.runtime.log.LogSystem

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

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 key="propertyKey" 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.

<export-object key="objectMapKey" name="velocityContextName"/> (optional; 0..n)

Export the object specified by key from the Cocoon object map to the Velocity context of the template. The object can be accessed from the template as name. Be careful to use a valid VTL variable name.

Default Java objects exported to the Velocity context:

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

The Cocoon current request

template (java.lang.String)

The path of the template file currently being evaluated

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

The Cocoon response 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

Additional Java objects can be exported from the Cocoon object map to the Velocity context by adding one or more <export-object key="objectMapKey" name="velocityContextName"/> child elements to the generator configuration in the sitemap.

Version:

CVS $Id: VelocityGenerator.java,v 1.8 2002/02/22 07:03:51 cziegeler Exp $

Author:

Davanum Srinivas, Michael McKibben

Inner Class Summary

static class

VelocityGenerator.TemplateLoader Velocity ResourceLoader implementation to load template resources using Cocoon's SourceResolver.

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

manager

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

objectModel, parameters, resolver, source

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

contentHandler, 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(org.apache.avalon.framework.configuration.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, java.lang.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, java.util.Map objectModel, java.lang.String src, org.apache.avalon.framework.parameters.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.ComposerGenerator

compose, dispose

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

setConsumer, setContentHandler, setLexicalHandler

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

getLogger, setLogger, 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(org.apache.avalon.framework.configuration.Configuration configuration)
               throws org.apache.avalon.framework.configuration.ConfigurationException

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

Specified by:

configure in interface org.apache.avalon.framework.configuration.Configurable

Parameters:

configuration - the class configurations.

See Also:

Configurable.configure(org.apache.avalon.framework.configuration.Configuration)

initialize

public void initialize()
                throws java.lang.Exception

Specified by:

initialize in interface org.apache.avalon.framework.activity.Initializable

See Also:

Initializable.initialize()

setup

public void setup(SourceResolver resolver,
                  java.util.Map objectModel,
                  java.lang.String src,
                  org.apache.avalon.framework.parameters.Parameters params)
           throws ProcessingException,
                  org.xml.sax.SAXException,
                  java.io.IOException

Description copied from class: AbstractGenerator

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

Overrides:

setup in class AbstractGenerator

See Also:

SitemapModelComponent.setup(org.apache.cocoon.environment.SourceResolver, java.util.Map, java.lang.String, org.apache.avalon.framework.parameters.Parameters)

recycle

public void recycle()

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

Overrides:

recycle in class AbstractGenerator

See Also:

Recyclable.recycle()

generate

public void generate()
              throws java.io.IOException,
                     org.xml.sax.SAXException,
                     ProcessingException

Generate XML data using Velocity template.

See Also:

Generator.generate()

init

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

This implementation does nothing.

Specified by:

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

See Also:

LogSystem.init(org.apache.velocity.runtime.RuntimeServices)

logVelocityMessage

public void logVelocityMessage(int level,
                               java.lang.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, java.lang.String)