ResourceBundleLambda.java

package org.trimou.lambda.i18n;

import java.util.ResourceBundle;

import org.trimou.engine.MustacheEngine;
import org.trimou.engine.MustacheEngineBuilder;
import org.trimou.engine.MustacheEngineBuilder.EngineBuiltCallback;
import org.trimou.engine.locale.LocaleSupport;
import org.trimou.engine.resolver.i18n.ResourceBundleResolver;
import org.trimou.handlebars.i18n.ResourceBundleHelper;
import org.trimou.lambda.InputProcessingLambda;
import org.trimou.util.Strings;

/**
 * Displays localized messages. It might be registered as a global lambda - see
 * {@link MustacheEngineBuilder#addGlobalData(String, Object)}.
 *
 * <pre>
 * {{#bundle}}key{{/bundle}}
 * </pre>
 *
 * @author Martin Kouba
 * @see ResourceBundle
 * @see ResourceBundleHelper
 * @see ResourceBundleResolver
 */
public class ResourceBundleLambda extends InputProcessingLambda
        implements EngineBuiltCallback {

    private String baseName;

    private LocaleSupport localeSupport;

    /**
     *
     * @param baseName
     */
    public ResourceBundleLambda(String baseName) {
        this.baseName = baseName;
    }

    /**
     *
     * @param baseName
     * @param localeSupport
     */
    public ResourceBundleLambda(String baseName, LocaleSupport localeSupport) {
        this.baseName = baseName;
        this.localeSupport = localeSupport;
    }

    @Override
    public String invoke(String text) {

        if (localeSupport == null) {
            throw new IllegalStateException(
                    "ResourceBundleLambda requires a LocaleSupport instance to work properly");
        }

        ResourceBundle bundle = ResourceBundle.getBundle(baseName,
                localeSupport.getCurrentLocale());

        if (bundle.containsKey(text)) {
            return bundle.getObject(text).toString();
        }
        return Strings.EMPTY;
    }

    @Override
    public boolean isReturnValueInterpolated() {
        return false;
    }

    @Override
    public void engineBuilt(MustacheEngine engine) {
        this.localeSupport = engine.getConfiguration().getLocaleSupport();
    }

}