/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You 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.apache.cocoon.forms.binding;

import org.apache.cocoon.forms.binding.library.Library;
import org.apache.cocoon.forms.formmodel.Widget;

/**
 * Binding declares the methods to 'bind' (i.e. 'load' and 'save')
 * information elements from some back-end model (2nd argument) to and from
 * a existing Cocoon Form Widget.
 *
 * @version $Id$
 */
public interface Binding {

    /**
     * Sets parent binding.
     * @param binding Parent of this binding.
     */
    void setParent(Binding binding);

    /**
     * Gets binding definition id.
     */
    String getId();

    /**
     * returns the local library for this tree of bindings
     */
    Library getEnclosingLibrary();

    /**
     * sets the library this binding is a part of
     */
    void setEnclosingLibrary(Library lib);

    /**
     * checks for deep validity of this binding tree (taking into accound included libraries)
     */
    boolean isValid();

    /**
     * Gets a binding class.
     * @param id Id of binding class to get.
     */
    Binding getClass(String id);

    /**
     * Loads the information-elements from the objModel to the frmModel.
     *
     * @param frmModel
     * @param objModel
     */
    void loadFormFromModel(Widget frmModel, Object objModel)
    throws BindingException;

    /**
     * Saves the infortmation-elements to the objModel from the frmModel.
     * @param frmModel
     * @param objModel
     */
    void saveFormToModel(Widget frmModel, Object objModel)
    throws BindingException;
}