com.techempower.gemini.internationalization.GeminiLocaleManager Maven / Gradle / Ivy
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package com.techempower.gemini.internationalization;
import java.util.*;
import com.techempower.gemini.*;
import com.techempower.util.*;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
/**
* GeminiLocaleManager is the "main" class of the Gemini internationalization
* components.
*
* Manages lookup and use of locale-specific user interface messages for
* Gemini and, optionally, applications built upon Gemini. The primary
* intent of GeminiLocaleManager is to provide a means to localize the
* user interface of Gemini's FormElements. However, this manager class
* can be used to provide localized user interface, in general, for
* Gemini applications.
*
* GeminiLocaleManager utilizes the ResourceManager class to handle the
* underlying data-source management of GeminiResources. This allows a greater
* flexibility for retrieval and management of GeminiResources.
*
* A DefaultGeminiResources class exists to provide US-English user interface
* to applications that have no internationalization needs.
*/
public class GeminiLocaleManager
implements Configurable
{
//
// Constants.
//
public static final String DEFAULT_LANGUAGE_CODE = "en";
public static final String DEFAULT_COUNTRY_CODE = "US";
private static final String SESSION_LOCALE_SUFFIX = "-Locale";
//
// Static variables.
//
/**
* Records an reference to the last-instantiated GeminiLocaleManager. Most
* applications will only ever instantiate one, so this is should always
* be the right reference.
*/
private static GeminiLocaleManager instance;
//
// Member variables.
//
private final Logger log = LoggerFactory.getLogger(getClass());
private volatile ResourceManager resourceManager;
private final GeminiApplication application;
private final String productName;
private final Locale defaultLocale;
private final GeminiResources defaultResources;
//
// Member methods.
//
/**
* Constructor.
*
* @param application The application reference.
* @param defaultResources A set of resources to use as a fail-safe if no
* resources can be loaded by the ResourceManager; this is usually
* a subclass of DefaultGeminiResources.
*/
public GeminiLocaleManager(GeminiApplication application,
GeminiResources defaultResources)
{
this.application = application;
this.productName = application.getVersion().getAbbreviatedProductName();
this.defaultLocale = new Locale(DEFAULT_LANGUAGE_CODE, DEFAULT_COUNTRY_CODE);
if (defaultResources != null)
{
this.defaultResources = defaultResources;
}
else
{
this.log.info("Instantiating built-in default (US English) resources.");
this.defaultResources = new DefaultGeminiResources(application);
}
// Register for configuration.
application.getConfigurator().addConfigurable(this);
instance = this;
}
/**
* Constructor. This simplified version uses a plain DefaultGeminiResources
* for the default resources.
*
* @param application The application reference.
*/
public GeminiLocaleManager(GeminiApplication application)
{
this(application, null);
}
/**
* Gets the static reference to the GeminiLocaleManager singleton (the
* most-recently instantiated GeminiLocaleManager, which is typically the
* -only- such object).
*/
public static GeminiLocaleManager getInstance()
{
return instance;
}
/**
* Configures this component. Reconfiguring the GeminiLocaleManager will
* recreate the ResourceManager, causing all resources to be reloaded.
*/
@Override
public void configure(EnhancedProperties props)
{
// We create a FileResourceManager, but in the future, we may have other
// configurable Managers for resources (e.g., DatabaseResourceManager).
this.resourceManager = new FileResourceManager(this.application, this, props);
}
/**
* Gets the default locale for this application.
*/
public Locale getDefaultLocale()
{
return this.defaultLocale;
}
/**
* Gets a reference to the default resources.
*/
public GeminiResources getDefaultResources()
{
return this.defaultResources;
}
/**
* Sets a user session's locale.
*
* @param languageID the Language ID for the Locale.
* @param countryID the Country ID for the Locale.
*/
public void setLocale(Context context, String languageID, String countryID)
{
context.session().putObject(this.productName + SESSION_LOCALE_SUFFIX,
new Locale(languageID, countryID));
}
/**
* Sets a user session's locale.
*/
public void setLocale(Context context, Locale locale)
{
context.session().putObject(this.productName + SESSION_LOCALE_SUFFIX, locale);
}
/**
* Gets a user session's locale. If no locale it set, the default locale
* is returned.
*/
public Locale getLocale(Context context)
{
if (context != null)
{
Locale toReturn = getLocaleRaw(context);
return (toReturn != null
? toReturn
: getDefaultLocale());
}
else
{
return getDefaultLocale();
}
}
/**
* Gets a user session's locale. If no locale is set for the session, null
* will be returned.
*/
public Locale getLocaleRaw(Context context)
{
return context.session().getObject(this.productName + SESSION_LOCALE_SUFFIX);
}
/**
* Gets a GeminiResources given a Context. If no appropriate resources are
* available, the default resources are returned.
*/
public GeminiResources getResources(Context context)
{
return getResources(getLocale(context));
}
/**
* Gets a GeminiResource from the ResourceManager based on the Locale.
*/
public GeminiResources getResources(Locale locale)
{
return this.resourceManager.get(locale);
}
/**
* Save the loaded resources to their underlying source.
*/
public boolean saveResources()
{
return this.resourceManager.save();
}
/**
* Removes a resources from the table for a specific Locale. This forces a
* reload of the resource data.
*/
public void resetResource(Locale locale)
{
this.resourceManager.reset(locale);
}
/**
* Removes all the loaded resources. This forces a reload of all Locales'
* resource data.
*/
public void resetResources()
{
this.resourceManager.reset();
}
/**
* Gets the reference to the application.
*/
protected GeminiApplication getApplication()
{
return this.application;
}
} // End GeminiLocaleManager.