org.wandora.modules.servlet

Class TemplateManager

java.lang.Object

org.wandora.modules.AbstractModule

org.wandora.modules.servlet.TemplateManager

All Implemented Interfaces:

Module

public class TemplateManager
extends AbstractModule

A module where all Templates register themselves so that Actions, or other modules too, can find them. The other modules refer to the templates with their template key, not the module name. In addition, a template version may also be specified. The combination of key and version has to be unique, there can be several templates with same key but different versions. While the key must match exactly to the requested template key, version matching is not exact. Instead a best match is used. See getTemplate method documentation for more details.

Manager specific default context variables can be specified in the initialisation parameters using the parameter name prefix "context.". The rest of the parameter is the context variable name. Note that template specific parameters can similarly be defined in the Template modules too (assuming they derive from the AbstractTemplate class).

A templatePath initialisation parameter can be given, which should point to a directory containing template files. Templates are not required to use this, in fact, templates are not required to access any files at all, but it is good practice to respect it. However, note that VelocityTemplates in particular do not use this. Instead the template directory for velocity templates is defined in the VelocityEngineModule.

A TemplateContextProvider module can be used to provide the default context. This is an optional dependency and will be used if it is found in the module manager but not having one is not an error. You can set the ignoreContextProvider initialisation parameter to true to override this behaviour. Both a context provider and context initialisation parameters in this class can be used at the same time. These contexts are merged into one default context. In case of context keys clashing, initialisation parameters of this module override the values of the context provider.

Author:

olli

Field Summary

Fields

Modifier and Type	Field and Description
protected TemplateContextProvider	contextProvider
protected java.util.HashMap<java.lang.String,java.lang.Object>	defaultContext
protected boolean	ignoreContextProvider
protected java.util.HashMap<java.lang.String,java.util.ArrayList<Template>>	templateMap
protected java.lang.String	templatePath

Fields inherited from class org.wandora.modules.AbstractModule

autoStart, isInitialized, isRunning, logging, loggingModule, moduleManager

Constructor Summary

Constructors

Constructor and Description
TemplateManager()

Method Summary

Modifier and Type	Method and Description
java.util.HashMap<java.lang.String,java.lang.Object>	getDefaultContext() Gets the manager specific default context which should be used as a basis for template contexts.
java.util.Collection<Module>	getDependencies(ModuleManager manager) Returns all the modules this module depends on.
Template	getTemplate(java.lang.String key, java.lang.String version) Gets the template using the specified key and version.
java.lang.String	getTemplatePath() Gets the specified path for template files.
void	init(ModuleManager manager, java.util.HashMap<java.lang.String,java.lang.Object> settings) Initialises the module.
void	putStaticContext(java.lang.String key, java.lang.Object o) Puts an object in the manager specific default template context.
void	registerTemplate(Template template) Register a template for this manager.
void	start(ModuleManager manager) Starts the module.
void	stop(ModuleManager manager) Stops the module.
void	unregisterTemplate(Template template) Unregisters a template.

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

templateMap

protected final java.util.HashMap<java.lang.String,java.util.ArrayList<Template>> templateMap

defaultContext

protected final java.util.HashMap<java.lang.String,java.lang.Object> defaultContext

contextProvider

protected TemplateContextProvider contextProvider

ignoreContextProvider

protected boolean ignoreContextProvider

templatePath

protected java.lang.String templatePath

Constructor Detail

TemplateManager

public TemplateManager()

Method Detail

getDefaultContext

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

Gets the manager specific default context which should be used as a basis for template contexts.

Returns:

The manager specific default template context.

putStaticContext

public void putStaticContext(java.lang.String key,
                             java.lang.Object o)

Puts an object in the manager specific default template context.

Parameters:

key - The key of the template variable.

o - The value of the template variable.

init

public void init(ModuleManager manager,
                 java.util.HashMap<java.lang.String,java.lang.Object> settings)
          throws ModuleException

Description copied from interface: Module

Initialises the module. After constructor, this is the first method called in the life cycle of a module. It should not perform anything time consuming or anything with notable outside side effects. It should only read the parameters and initialise the module so that it can later be started. Note that a module being initialised doesn't mean that it necessarily will ever be started.

A ModuleException may be thrown if something vital is missing from the parameters or they are not sensible. In some cases you may not want to throw an exception even if vital initialisation information is missing. If, for example, it is possible that the module is initialised in some other way between the init and the start method calls. A ModuleException may also be thrown at the start method if the module is still not initialised.

Specified by:

init in interface Module

Overrides:

init in class AbstractModule

Parameters:

manager - The module manager handling this module. You may keep a reference to it if needed.

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 AbstractModule

Parameters:

manager - The module manager handling this module.

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 AbstractModule

Parameters:

manager - The module manager handling this module.

Throws:

ModuleException

getTemplatePath

public java.lang.String getTemplatePath()

Gets the specified path for template files.

Returns:

The template path.

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 AbstractModule

Parameters:

manager - The module manager handling this module.

Returns:

A collection of modules this module depends on.

Throws:

ModuleException

getTemplate

public Template getTemplate(java.lang.String key,
                            java.lang.String version)

Gets the template using the specified key and version. The key must match exactly with the key the template was registered with but version matching is fuzzy. If multiple versions of the same template have been registered, the one with the most matching characters from the start is used. You can always use null for version if you don't use different template versions.

Parameters:

key - The key of the template to get.

version - The version of the template, or null if not applicable.

Returns:

The template that should be used, or null if no suitable template was found.

registerTemplate

public void registerTemplate(Template template)

Register a template for this manager. After this, the manager may return the template when getTemplate is called.

Parameters:

template - The template to register.

unregisterTemplate

public void unregisterTemplate(Template template)

Unregisters a template. After this, the template will no longer be returned as a result of getTemplate.

Parameters:

template - The template to unregister.