/*
* Copyright 2014 The original authors
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.vaadin.spring.i18n;
import com.vaadin.ui.UI;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.context.ApplicationContext;
import org.springframework.context.NoSuchMessageException;
import java.io.Serializable;
import java.util.Locale;
/**
* Helper class for resolving messages in a Vaadin UI. This is effectively a wrapper around {@link org.springframework.context.ApplicationContext}
* that uses the locale of the current UI to lookup messages. Use it like this:
* <pre>
* @VaadinUI
* public class MyUI extends UI {
*
* @Autowired I18N i18n;
*
* ...
*
* void init() {
* myLabel.setCaption(i18n.get("myLabel.caption"));
* }
* }
* </pre>
* Please note, that you also need to configure a {@link org.springframework.context.MessageSource} inside your application context
* that contains all the messages to resolve.
*
* @author Petter Holmström (petter@vaadin.com)
*/
public class I18N implements Serializable {
private final ApplicationContext applicationContext;
private final Logger logger = LoggerFactory.getLogger(getClass());
/**
* @param applicationContext the application context to read messages from, never {@code null}.
*/
@Autowired
public I18N(ApplicationContext applicationContext) {
this.applicationContext = applicationContext;
}
/**
* Tries to resolve the specified message for the current locale.
*
* @param code the code to lookup up, such as 'calculator.noRateSet', never {@code null}.
* @param arguments Array of arguments that will be filled in for params within the message (params look like "{0}", "{1,date}", "{2,time}"), or {@code null} if none.
* @return the resolved message, or the message code prepended with an exclamation mark if the lookup fails.
* @see org.springframework.context.ApplicationContext#getMessage(String, Object[], java.util.Locale)
* @see #getLocale()
*/
public String get(String code, Object... arguments) {
try {
return applicationContext.getMessage(code, arguments, getLocale());
} catch (NoSuchMessageException ex) {
logger.warn("Tried to retrieve message with code [{}] that does not exist", code);
return "!" + code;
}
}
/**
* Tries to resolve the specified message for the current locale.
*
* @param code the code to lookup up, such as 'calculator.noRateSet', never {@code null}.
* @param defaultMessage string to return if the lookup fails, never {@code null}.
* @param arguments Array of arguments that will be filled in for params within the message (params look like "{0}", "{1,date}", "{2,time}"), or {@code null} if none.
* @return the resolved message, or the {@code defaultMessage} if the lookup fails.
* @see org.springframework.context.ApplicationContext#getMessage(String, Object[], String, java.util.Locale)
* @see #getLocale()
*/
public String getWithDefault(String code, String defaultMessage, Object... arguments) {
return applicationContext.getMessage(code, arguments, defaultMessage, getLocale());
}
/**
* Gets the locale of the current Vaadin UI. If the locale can not be determinted, the default locale
* is returned instead.
*
* @return the current locale, never {@code null}.
* @see com.vaadin.ui.UI#getLocale()
* @see java.util.Locale#getDefault()
*/
public Locale getLocale() {
UI currentUI = UI.getCurrent();
Locale locale = (currentUI == null ? null : currentUI.getLocale());
if (locale == null) {
locale = Locale.getDefault();
}
return locale;
}
}