org.apache.shale.clay.config.beans
Class ComponentConfigBean

java.lang.Object
  org.apache.shale.clay.config.beans.ComponentConfigBean

All Implemented Interfaces:

Comparable, ConfigBean

Direct Known Subclasses:

TemplateConfigBean

public class ComponentConfigBean
extends Object
implements ConfigBean

This class is kind of the metadata object pool for configuration data loaded from XML files on startup in the ClayConfigureListener by the ClayXmlParser. An instance of this class will be registered with the ConfigBeanFactory.

Nested Class Summary

protected class	ComponentConfigBean.WatchDog This inner class watches for changes in a array of ConfigBean.ConfigDefinition's.
protected class	ComponentConfigBean.XmlConfigDef This class defines a single configration file that is watched for changes.

Nested classes/interfaces inherited from interface org.apache.shale.clay.config.beans.ConfigBean

ConfigBean.ConfigDefinition

Field Summary

protected ServletContext	context Reference to the ServletContext.
protected Map	displayElements Collection holding all the top-level components defined in the XML config files.
protected boolean	isWatchDogOn This parameter is initialized from the init method from the org.apache.shale.clay.AUTO_RELOAD_CONFIG_FILES init parameter in the web.xml.
protected static org.apache.shale.util.Messages	messages Message resources for this class.
protected static String[]	NAMING_CONTAINER_TYPES A static string array of faces component types that are naming containers.
protected ClayConfigParser	parser Uses the digester to load the configuration files into a object graph cached in displayElements.
protected String[]	suffixes The suffixes used to identify that a jsfid is a template style of composition.
protected Map	watchDogs Map of ComponentConfigBean.WatchDog that watches the configuration files looking for changes.

Constructor Summary

ComponentConfigBean()
Constructor initializes the displayElements collection.

Method Summary

void	addChild(ComponentBean obj) Adds a {link ComponentBean} to the displayElement map collection using the jsfid as the key.
void	assignParent(ComponentBean b) Called to assign the IsA parent to the ComponentBean using the extends attribute.
protected void	checkCircularInheritance(ComponentBean b) Passed a ComponentBean, the method looks for several types of circular inheritances.
void	checkTree(ComponentBean b) Recursively walks the tree of component metadata verifying there is not a duplicate component id within a naming container.
protected void	checkTree(List componentIds, ComponentBean b) Verifies there is not a duplicate component id within a naming container.
protected void	clear(String watchDogName) Cleans up before a group of files are reloaded.
int	compareTo(Object config) Implementation of the Comparable interface.
protected StringBuffer	describeRelationships(Stack heritage) Returns a StringBuffer with an xpath like expression of jsfid that describes the Stack of ComponentBean.
void	destroy() The destroy method is invoked to clean up resources.
protected Stack	getAssociations(ComponentBean b) Walks up the hasA parent chain looking for circular relationships.
protected ConfigBean.ConfigDefinition[]	getConfigDefinitions(String configFiles) Passed a comma delimited list of configuration files, this method returns an array of ConfigBean.ConfigDefinition defining the files.
ComponentBean	getElement(String jsfid) Factory method that returns a top-level {link ComponentBean} with a matching jsfid or null if not found.
protected Stack	getGeneralizations(ComponentBean b) Walks up the isA parent chain looking for circular relationships.
ServletContext	getServletContext() Returns the web container ServletContext.
protected ComponentBean	getTopLevelElement(String jsfid) Returns the root metadata component that is used to add to the component tree.
int	getWeight() The weight is an attempt to make a plug-able system for registering ConfigBean objects with the ConfigBeanFactory.
void	init(ServletContext context) Initialization method that is passed the ServletContext as a parameter.
boolean	isDesigntime() Returns true if the current mode is design time.
protected boolean	isNamingContainer(String componentType) Checks the componentType against the NAMING_CONTAINER_TYPES list to determine if it is a naming container.
protected void	loadConfigFiles() Loads the Clay configration files into the displayElements Map.
protected void	realizingInheritance(AttributeBean a) This overload handles fixing up AttributeBean inheritance.
void	realizingInheritance(ComponentBean b) This method is passed a ComponentBean and is recursively called for each contained component.
boolean	refresh(boolean forceReload) This method should be called from key points in the application to invoke automatic reloading of the configuration files if they have been modified since last reloaded.
void	resolveInheritance() This method is called on startup to resolve the meta inheritance relationships for each top-level components in the displayElements collection.
void	setDesigntime(boolean isDesigntime) Sets the design time to somthing other than the default false value.
protected void	unassignParent(ComponentBean b) Recursively called to unassign isA and hasA parent relationships.
boolean	validMoniker(String id) Called by the ConfigBeanFactory to determine if this instance of ConfigBean can handle finding the ConfigBean from the jsfid.

Methods inherited from class java.lang.Object

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

Field Detail

parser

protected ClayConfigParser parser

Uses the digester to load the configuration files into a object graph cached in displayElements.

isWatchDogOn

protected boolean isWatchDogOn

This parameter is initialized from the init method from the org.apache.shale.clay.AUTO_RELOAD_CONFIG_FILES init parameter in the web.xml. The default value is true which will trigger reloading the files when a change has occurred.

watchDogs

protected Map watchDogs

Map of ComponentConfigBean.WatchDog that watches the configuration files looking for changes. The configuration files are defined by the ConfigBean.ConfigDefinition top level interface.

messages

protected static org.apache.shale.util.Messages messages

Message resources for this class.

suffixes

protected String[] suffixes

The suffixes used to identify that a jsfid is a template style of composition. If it has a matching suffix, it will be handled by the TemplateConfigBean or TemplateComponentConfigBean; Otherwise, it's handled by ComponentConfigBean.

context

protected transient ServletContext context

Reference to the ServletContext.

displayElements

protected Map displayElements

Collection holding all the top-level components defined in the XML config files.

NAMING_CONTAINER_TYPES

protected static final String[] NAMING_CONTAINER_TYPES

A static string array of faces component types that are naming containers.

Constructor Detail

ComponentConfigBean

public ComponentConfigBean()

Constructor initializes the displayElements collection.

Method Detail

isDesigntime

public boolean isDesigntime()

Returns true if the current mode is design time.

Returns:

true if design time

setDesigntime

public void setDesigntime(boolean isDesigntime)

Sets the design time to somthing other than the default false value.

Parameters:

isDesigntime - load config descriptions

init

public void init(ServletContext context)

Initialization method that is passed the ServletContext as a parameter. Loads the sufixes for the ServletContext initialization parameter.

Specified by:

init in interface ConfigBean

Parameters:

context - servlet context

loadConfigFiles

protected void loadConfigFiles()

Loads the Clay configration files into the displayElements Map. The files are defined by the clay-template-suffix initialization parameter in the web deployment descriptor. The default configuration file "META-INF/view-config.xml" is always loaded from the shale-clay java archive.

getConfigDefinitions

protected ConfigBean.ConfigDefinition[] getConfigDefinitions(String configFiles)

Passed a comma delimited list of configuration files, this method returns an array of ConfigBean.ConfigDefinition defining the files.

Parameters:

configFiles - comma seperated list of config files

Returns:

config definitions for the files

getServletContext

public ServletContext getServletContext()

Returns the web container ServletContext.

Specified by:

getServletContext in interface ConfigBean

Returns:

servlet context

getElement

public ComponentBean getElement(String jsfid)

Factory method that returns a top-level {link ComponentBean} with a matching jsfid or null if not found.

Specified by:

getElement in interface ConfigBean

Parameters:

jsfid - id of component definition

Returns:

component definition for the jsfid

addChild

public void addChild(ComponentBean obj)

Adds a {link ComponentBean} to the displayElement map collection using the jsfid as the key.

Parameters:

obj - component bean added to the map of elements

resolveInheritance

public void resolveInheritance()

This method is called on startup to resolve the meta inheritance relationships for each top-level components in the displayElements collection. There are three steps, find parents, check for circular relationships, and realize the relationships.

getTopLevelElement

protected ComponentBean getTopLevelElement(String jsfid)

Returns the root metadata component that is used to add to the component tree. This method might be overridden to broaden the scope to search for components outside of the displayElement cache.

Parameters:

jsfid - id of a component bean

Returns:

component bean

assignParent

public void assignParent(ComponentBean b)

Called to assign the IsA parent to the ComponentBean using the extends attribute.

Specified by:

assignParent in interface ConfigBean

Parameters:

b - component bean needing isa parent assigned

realizingInheritance

protected void realizingInheritance(AttributeBean a)

This overload handles fixing up AttributeBean inheritance.

Parameters:

a - attribute needing inheritance resolved

realizingInheritance

public void realizingInheritance(ComponentBean b)

This method is passed a ComponentBean and is recursively called for each contained component. It fixes up the meta inheritance relationships.

Specified by:

realizingInheritance in interface ConfigBean

Parameters:

b - component bean needing inheritance realized

getGeneralizations

protected Stack getGeneralizations(ComponentBean b)

Walks up the isA parent chain looking for circular relationships. It returns a Stack of ComponentBean documenting the heritage. A runtime exception is thrown if a circular relationship is found.

Parameters:

b - component bean having inheritance checked

Returns:

inheritance stack

getAssociations

protected Stack getAssociations(ComponentBean b)

Walks up the hasA parent chain looking for circular relationships. It returns a Stack of ComponentBean documenting the composition. A runtime exception is thrown if a circular relationship is found.

Parameters:

b - component bean having composition checked

Returns:

stack of parents

describeRelationships

protected StringBuffer describeRelationships(Stack heritage)

Returns a StringBuffer with an xpath like expression of jsfid that describes the Stack of ComponentBean.

Parameters:

heritage - stack of relationships to report on

Returns:

description of the stack

checkCircularInheritance

protected void checkCircularInheritance(ComponentBean b)

Passed a ComponentBean, the method looks for several types of circular inheritances. It's recursively called for all contained components, children, validators, actionListeners, valueChangeListeners and Converter. A runtime exception is thrown if a invalid relationship is found.

Parameters:

b - component bean to check

unassignParent

protected void unassignParent(ComponentBean b)

Recursively called to unassign isA and hasA parent relationships.

Parameters:

b - component bean

clear

protected void clear(String watchDogName)

Cleans up before a group of files are reloaded.

Parameters:

watchDogName - group name for a group of config files or templates

destroy

public void destroy()

The destroy method is invoked to clean up resources. By dereferencing the complex graph of display elements

Specified by:

destroy in interface ConfigBean

validMoniker

public boolean validMoniker(String id)

Called by the ConfigBeanFactory to determine if this instance of ConfigBean can handle finding the ConfigBean from the jsfid.

Specified by:

validMoniker in interface ConfigBean

Parameters:

id - jsfid

Returns:

true if the jsfid can be handled

compareTo

public int compareTo(Object config)

Implementation of the Comparable interface. The weight is used to determine the ordering of the registered ConfigBean objects within the ConfigBeanFactory.

Specified by:

compareTo in interface Comparable

Parameters:

config - object to compare to

Returns:

compares the weight of two config handlers

getWeight

public int getWeight()

The weight is an attempt to make a plug-able system for registering ConfigBean objects with the ConfigBeanFactory. A custom implementation could be registered for a different composition technique adding or overriding an existing implementation.

Specified by:

getWeight in interface ConfigBean

Returns:

0

refresh

public boolean refresh(boolean forceReload)

This method should be called from key points in the application to invoke automatic reloading of the configuration files if they have been modified since last reloaded. If the forceReload flag is true the files are reloaded. A true return value indicates the config files were reloaded.

Specified by:

refresh in interface ConfigBean

Parameters:

forceReload - reload the files

Returns:

files were reloaded

isNamingContainer

protected boolean isNamingContainer(String componentType)

Checks the componentType against the NAMING_CONTAINER_TYPES list to determine if it is a naming container. Component id's must be unique within a naming container. Returns a true value if the componentType is a naming container; otherwise, returns false.

Parameters:

componentType - type of the component

Returns:

true if the component type is a naming comtainer

checkTree

public void checkTree(ComponentBean b)

Recursively walks the tree of component metadata verifying there is not a duplicate component id within a naming container. A root ComponentBean is passed as a single parameter. The overloaded checkTree(List, ComponentBean) is invoked to process components under a naming container.

Specified by:

checkTree in interface ConfigBean

Parameters:

b - root of the component tree

checkTree

protected void checkTree(List componentIds,
                         ComponentBean b)

Verifies there is not a duplicate component id within a naming container. A list of accumulating componentIds and a root ComponentBean is passed as parameters. A runtime exception is thrown if a duplicate id is encountered.

Parameters:

componentIds - list of component id's in the naming container

b - parent component bean