001// Copyright 2005 The Apache Software Foundation
002//
003// Licensed under the Apache License, Version 2.0 (the "License");
004// you may not use this file except in compliance with the License.
005// You may obtain a copy of the License at
006//
007//     http://www.apache.org/licenses/LICENSE-2.0
008//
009// Unless required by applicable law or agreed to in writing, software
010// distributed under the License is distributed on an "AS IS" BASIS,
011// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
012// See the License for the specific language governing permissions and
013// limitations under the License.
014
015package org.apache.tapestry.form.translator;
016
017import java.util.Locale;
018
019import org.apache.tapestry.form.IFormComponent;
020import org.apache.tapestry.form.FormComponentContributor;
021import org.apache.tapestry.form.ValidationMessages;
022import org.apache.tapestry.valid.ValidatorException;
023
024/**
025 * Interface used by {@link ValidatableField}s to both format an object as text and translate
026 * submitted text into an appropriate object for a given field.
027 * 
028 * @author Paul Ferraro
029 * @since 4.0
030 */
031public interface Translator extends FormComponentContributor
032{
033    /**
034     * Invoked during rendering to format an object (which may be null) into a text value (which
035     * should not be null) appropriate for the specified field.
036     * @param locale TODO
037     */
038    public String format(IFormComponent field, Locale locale, Object object);
039
040    /**
041     * Invoked during rewind to parse a submitted input value into an object suitable for the
042     * specified component.
043     * @param messages TODO
044     * 
045     * @return the parsed object
046     * @throws ValidatorException
047     *             if the specified text could not be parsed into an object.
048     */
049    public Object parse(IFormComponent field, ValidationMessages messages, String value) throws ValidatorException;
050}