org.wandora.modules.servlet

Class VelocityTemplate

java.lang.Object

org.wandora.modules.AbstractModule

org.wandora.modules.servlet.AbstractTemplate

org.wandora.modules.servlet.VelocityTemplate

All Implemented Interfaces:

Module, Template

public class VelocityTemplate
extends AbstractTemplate

A Template implementation using the Apache Velocity templating engine. The engine itself is required as a separate module, VelocityEngineModule. The base functionality is defined in the AbstractTemplate base class and only the actual template processing is done here.

A few items are automatically added in the template context, in addition to the ones specified in initialisation parameters, as described in AbstractTemplate documentation. These are used to overcome some of the limitations in Velocity template language. The urlencoder parameter contains a URLEncoder object which can help with encoding values used in URLs. listmaker variable contains an InstanceMaker that can make ArrayLists, it is difficult to create new lists in Velocity without this. These helper classes are defined in org.wandora.modules.velocityhelpers along with other similar helpers, which you may want to add to the context manually.

Author:

olli

Field Summary

Fields

Modifier and Type	Field and Description
protected VelocityEngineModule	engineModule
protected org.apache.velocity.Template	vTemplate

Fields inherited from class org.wandora.modules.servlet.AbstractTemplate

templateCaching, templateContext, templateEncoding, templateFile, templateKey, templateManager, templateMime, templateVersion

Fields inherited from class org.wandora.modules.AbstractModule

autoStart, isInitialized, isRunning, logging, loggingModule, moduleManager

Constructor Summary

Constructors

Constructor and Description
VelocityTemplate()

Method Summary

Modifier and Type	Method and Description
java.util.Collection<Module>	getDependencies(ModuleManager manager) Returns all the modules this module depends on.
protected java.lang.String	getFullTemplatePath()
java.util.HashMap<java.lang.String,java.lang.Object>	getTemplateContext() Returns the default context for this template.
protected org.apache.velocity.app.VelocityEngine	getVelocityEngine()
void	process(java.util.HashMap<java.lang.String,java.lang.Object> params, java.io.OutputStream output) Processes the template with the given context and writes the resulting content in the output stream.
void	start(ModuleManager manager) Starts the module.
void	stop(ModuleManager manager) Stops the module.

Methods inherited from class org.wandora.modules.servlet.AbstractTemplate

getEncoding, getKey, getMimeType, getVersion, init

Methods inherited from class org.wandora.modules.AbstractModule

isInitialized, isRunning, requireLogging, toString

Methods inherited from class java.lang.Object

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

Field Detail

vTemplate

protected org.apache.velocity.Template vTemplate

engineModule

protected VelocityEngineModule engineModule

Constructor Detail

VelocityTemplate

public VelocityTemplate()

Method Detail

getVelocityEngine

protected org.apache.velocity.app.VelocityEngine getVelocityEngine()

getFullTemplatePath

protected java.lang.String getFullTemplatePath()

Overrides:

getFullTemplatePath in class AbstractTemplate

getDependencies

public java.util.Collection<Module> getDependencies(ModuleManager manager)
                                             throws ModuleException

Description copied from interface: Module

Returns all the modules this module depends on. This method will be called after init and the dependencies are allowed to depend on the parameters passed to init. The modules that this module depends on must be returned as a collection. In addition, if any required module is not present, a MissingDependencyException should be thrown. Typically you will use the requireModule and optionalModule methods of the manager to make sure that the modules exist and add them to the collection. requireModule will automatically throw the exception too if the module is not found whereas optionalModule does not.

Specified by:

getDependencies in interface Module

Overrides:

getDependencies in class AbstractTemplate

Parameters:

manager - The module manager handling this module.

Returns:

A collection of modules this module depends on.

Throws:

ModuleException

start

public void start(ModuleManager manager)
           throws ModuleException

Description copied from interface: Module

Starts the module. This will be called after init and getDependencies and signals that the module should now begin to perform whatever it was designed to do. This method call however should not block for long, so any time consuming tasks should be started in their own threads. You will typically get references to the required modules again in start using the findModule method of the manager and then store those references to instance variables for later use. You may throw a ModuleException if the module is not in a state where it can be started or it immediately becomes obvious that it cannot be started with the provided settings.

Specified by:

start in interface Module

Overrides:

start in class AbstractTemplate

Parameters:

manager - The module manager handling this module.

Throws:

ModuleException

stop

public void stop(ModuleManager manager)

Description copied from interface: Module

Stops the module. Should stop all threads used by the module, free any large data structures and perform other cleanup. It is possible that the module will be started again later with a start method call (and foregoing init and getDependencies calls). The module should be left in a state where this is possible.

Specified by:

stop in interface Module

Overrides:

stop in class AbstractTemplate

Parameters:

manager - The module manager handling this module.

getTemplateContext

public java.util.HashMap<java.lang.String,java.lang.Object> getTemplateContext()

Description copied from interface: Template

Returns the default context for this template. You may then add more content into the context before passing it on to process.

Specified by:

getTemplateContext in interface Template

Overrides:

getTemplateContext in class AbstractTemplate

Returns:

The default context of the template.

process

public void process(java.util.HashMap<java.lang.String,java.lang.Object> params,
                    java.io.OutputStream output)

Description copied from interface: Template

Processes the template with the given context and writes the resulting content in the output stream.

Specified by:

process in interface Template

Specified by:

process in class AbstractTemplate

Parameters:

params - The template context used for processing of the template.

output - The output stream where the result is written.