org.apache.velocity.tools.view.i18n
Class MultiViewsTool

java.lang.Object
  org.apache.velocity.tools.view.i18n.MultiViewsTool

All Implemented Interfaces:

ViewTool

public class MultiViewsTool

extends java.lang.Object

implements ViewTool

Allows for transparent content negotiation in a manner mimicking Apache httpd's MultiViews.

Reads the default language out of the ViewContext as org.apache.velocity.tools.view.i18n.defaultLanguage. See findLocalizedResource(String, String) and findLocalizedResource(String, Locale) for usage.

Version:

$Id: MultiViewsTool.html,v 1.8.2.1 2004/05/17 17:09:45 nbubna Exp $

Author:

Daniel Rall

Field Summary

protected static java.lang.String	DEFAULT_LANGUAGE_KEY The key used to search initialization, context, and JVM parameters for the default language to use.
protected java.lang.String	defaultLanguage The two character abbreviation for the request's default language.

Constructor Summary

MultiViewsTool()
Creates a new uninitialized instance.

Method Summary

java.lang.String	findLocalizedResource(java.lang.String name) Calls findLocalizedResource(String, String) using the default language.
java.lang.String	findLocalizedResource(java.lang.String name, java.util.Locale locale) Calls findLocalizedResource(String, String) using the language extracted from locale.
java.lang.String	findLocalizedResource(java.lang.String name, java.lang.String language) Finds the a localized version of the requested Velocity resource (such as a file or template) which is most appropriate for the locale of the current request.
void	init(java.lang.Object obj) Extracts the default language from the specified ViewContext, looking first at the Velocity context, then the servlet context, then lastly at the JVM default.

Methods inherited from class java.lang.Object

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

Field Detail

DEFAULT_LANGUAGE_KEY

protected static final java.lang.String DEFAULT_LANGUAGE_KEY

The key used to search initialization, context, and JVM parameters for the default language to use.

See Also:

Constant Field Values

defaultLanguage

protected java.lang.String defaultLanguage

The two character abbreviation for the request's default language.

Constructor Detail

MultiViewsTool

public MultiViewsTool()

Creates a new uninitialized instance. Call init(java.lang.Object) to initialize it.

Method Detail

init

public void init(java.lang.Object obj)

Extracts the default language from the specified ViewContext, looking first at the Velocity context, then the servlet context, then lastly at the JVM default. This "narrow scope to wide scope" pattern makes it easy to setup language overrides at different levels within your application.

Specified by:

init in interface ViewTool

Parameters:

obj - the current ViewContext

Throws:

java.lang.IllegalArgumentException - if the param is not a ViewContext

findLocalizedResource

public java.lang.String findLocalizedResource(java.lang.String name,
                                              java.util.Locale locale)

Calls findLocalizedResource(String, String) using the language extracted from locale.

See Also:

findLocalizedResource(String, String)

findLocalizedResource

public java.lang.String findLocalizedResource(java.lang.String name)

Calls findLocalizedResource(String, String) using the default language.

See Also:

findLocalizedResource(String, String)

findLocalizedResource

public java.lang.String findLocalizedResource(java.lang.String name,
                                              java.lang.String language)

Finds the a localized version of the requested Velocity resource (such as a file or template) which is most appropriate for the locale of the current request. Use in conjuction with Apache httpd's MultiViews, or by itself.

Usage from a template would be something like the following:

 #parse ($multiviews.findLocalizedResource("header.vm", "en"))
 #include ($multiviews.findLocalizedResource("my_page.html", "en"))
 #parse ($multiviews.findLocalizedResource("footer.vm", "en"))
 

You might also wrap this method using another pull/view tool which does internationalization/localization/content negation for a single point of access.

Parameters:

name - The unlocalized name of the file to find.

language - The language to find localized context for.

Returns:

The localized file name, or name if it is not localizable.