001// Copyright 2004, 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.binding;
016
017import org.apache.hivemind.Location;
018import org.apache.tapestry.IBinding;
019import org.apache.tapestry.IComponent;
020
021/**
022 * Creates a new instance of {@link org.apache.tapestry.IBinding}.
023 * 
024 * @author Howard Lewis Ship
025 * @since 4.0
026 */
027public interface BindingFactory
028{
029    /**
030     * Creates a new binding instance.
031     * 
032     * @param root
033     *            the component that is the source of properties or messages (or etc.). When the
034     *            path is "evaluated", the root component provides a context.
035     * @param description
036     *            The {@link IBinding#getDescription() description}of the binding.
037     * @param expression
038     *            The expression used to get (or update) a value. The interpretation of this
039     *            expression is determined by the type of {@link IBinding} created by this factory.
040     *            In some cases, it is simple the name of an object contained by the root component.
041     *            For the common "ognl:" binding prefix, it is an OGNL expression to be evaluated on
042     *            the root object.
043     * @param location
044     *            The location of the binding, used to report any errors related to the binding, or
045     *            to the component parameter the binding is bound to.
046     */
047    public IBinding createBinding(IComponent root, String bindingDescription, String expression,
048            Location location);
049}