org.apache.tapestry5.internal.services
Class MessagesSourceImpl

java.lang.Object
  org.apache.tapestry5.internal.event.InvalidationEventHubImpl
      org.apache.tapestry5.internal.services.MessagesSourceImpl

All Implemented Interfaces:

MessagesSource, InvalidationEventHub, UpdateListener

public class MessagesSourceImpl
extends InvalidationEventHubImpl
implements MessagesSource

A utility class that encapsulates all the logic for reading properties files and assembling Messages from them, in accordance with extension rules and locale. This represents code that was refactored out of ComponentMessagesSourceImpl. This class can be used as a base class, though the existing code base uses it as a utility. Composition trumps inheritance!

The message catalog for a component is the combination of all appropriate properties files for the component, plus any keys inherited form base components and, ultimately, the application global message catalog. At some point we should add support for per-library message catalogs.

Message catalogs are read using the UTF-8 character set. This is tricky in JDK 1.5; we read the file into memory then feed that bytestream to Properties.load().

Constructor Summary

MessagesSourceImpl(boolean productionMode, URLChangeTracker tracker, ComponentResourceLocator resourceLocator, PropertiesFileParser propertiesFileParser)

Method Summary

void	checkForUpdates() Invoked to force the receiver to check for updates to whatever underlying resources it makes use of.
Messages	getMessages(MessagesBundle bundle, ComponentResourceSelector selector) Used to obtain a Messages instance for a particular component, within a particular locale.

Methods inherited from class org.apache.tapestry5.internal.event.InvalidationEventHubImpl

addInvalidationListener, fireInvalidationEvent

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.apache.tapestry5.services.InvalidationEventHub

addInvalidationListener

Constructor Detail

MessagesSourceImpl

public MessagesSourceImpl(boolean productionMode,
                          URLChangeTracker tracker,
                          ComponentResourceLocator resourceLocator,
                          PropertiesFileParser propertiesFileParser)

Method Detail

checkForUpdates

public void checkForUpdates()

Description copied from interface: UpdateListener

Invoked to force the receiver to check for updates to whatever underlying resources it makes use of.

Specified by:

checkForUpdates in interface UpdateListener

getMessages

public Messages getMessages(MessagesBundle bundle,
                            ComponentResourceSelector selector)

Description copied from interface: MessagesSource

Used to obtain a Messages instance for a particular component, within a particular locale. If the component extends from another component, then its localized properties will merge with its parent's properties (with the subclass overriding the super class on any conflicts).

Specified by:

getMessages in interface MessagesSource

Parameters:

bundle - defines the set of properties files to read, as well as a series of parent bundles to extend and override

selector - defines the locale and other axes used to locate the necessary resources

Returns:

the message catalog for the bundle, for the indicated selector