NumberFormatResolver.java

/*
 * Copyright 2013 Martin Kouba
 *
 * 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.trimou.engine.resolver.i18n;

import static org.trimou.engine.priority.Priorities.rightAfter;

import java.text.NumberFormat;

import org.trimou.engine.resolver.ArrayIndexResolver;
import org.trimou.engine.resolver.ResolutionContext;
import org.trimou.engine.resolver.TransformResolver;

/**
 * Basic number formatting resolver.
 *
 * Acceptable names:
 * <ul>
 * <li>format - format number with the current locale</li>
 * <li>formatPercent - format number with the percentage pattern and the current
 * locale</li>
 * <li>formatCurrency - format number with the currency pattern and the current
 * locale</li>
 * </ul>
 *
 * @author Martin Kouba
 */
public class NumberFormatResolver extends TransformResolver {

    public static final int NUMBER_FORMAT_RESOLVER_PRIORITY = rightAfter(ArrayIndexResolver.ARRAY_RESOLVER_PRIORITY);

    static final String NAME_FORMAT = "format";

    static final String NAME_FORMAT_PERCENT = "formatPercent";

    static final String NAME_FORMAT_CURR = "formatCurrency";

    /**
     *
     */
    public NumberFormatResolver() {
        this(NUMBER_FORMAT_RESOLVER_PRIORITY);
    }

    /**
     *
     * @param priority
     */
    public NumberFormatResolver(int priority) {
        super(priority, NAME_FORMAT, NAME_FORMAT_CURR, NAME_FORMAT_PERCENT);
    }

    @Override
    protected boolean matches(Object contextObject, String name) {
        return super.matches(contextObject, name)
                && (contextObject instanceof Number);
    }

    @Override
    public Object transform(Object contextObject, String name,
            ResolutionContext context) {

        if (NAME_FORMAT.equals(name)) {
            return NumberFormat.getNumberInstance(getCurrentLocale()).format(
                    contextObject);
        } else if (NAME_FORMAT_PERCENT.equals(name)) {
            return NumberFormat.getPercentInstance(getCurrentLocale()).format(
                    contextObject);
        } else if (NAME_FORMAT_CURR.equals(name)) {
            return NumberFormat.getCurrencyInstance(getCurrentLocale()).format(
                    contextObject);
        }
        return null;
    }

}