    001    // Copyright 2006, 2007, 2008 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
    015    package org.apache.tapestry5.services;
    016
    017    import org.apache.tapestry5.Binding;
    018    import org.apache.tapestry5.ComponentResources;
    019    import org.apache.tapestry5.ioc.Location;
    020    import org.apache.tapestry5.ioc.annotations.UsesMappedConfiguration;
    021
    022    /**
    023     * Used to acquire bindings for component parameters. The BindingSource service strips off the binding prefix to locate
    024     * a {@link org.apache.tapestry5.services.BindingFactory}.
    025     */
    026    @UsesMappedConfiguration(BindingFactory.class)
    027    public interface BindingSource
    028    {
    029        /**
    030         * Examines the expression and strips off the leading prefix. The prefix is used to choose the appropriate {@link
    031         * BindingFactory}, which receives the description, the expression (after the prefix), and the location. If the
    032         * prefix doesn't exist, or if there's no prefix, then the factory for the default prefix (often "literal") is used
    033         * (and passed the full prefix).
    034         * <p/>
    035         * The binding represents a connection between the container and the component (the component is usually the child
    036         * of the container, though in a few cases, it is the component itself). In most cases, the expression is evaluated
    037         * in terms of the resources of the <em>container</em> and the component is ignored.
    038         *
    039         * @param description   description of the binding, such as "parameter foo"
    040         * @param container     typically, the parent of the component
    041         * @param component     the component whose parameter is to be bound
    042         * @param defaultPrefix the default prefix used when the expression itself does not have a prefix
    043         * @param expression    the binding
    044         * @param location      location assigned to the binding (or null if not known)
    045         * @return a binding
    046         */
    047        Binding newBinding(String description, ComponentResources container, ComponentResources component,
    048                           String defaultPrefix, String expression, Location location);
    049
    050        /**
    051         * A simpler version of {@link #newBinding(String, ComponentResources, ComponentResources, String, String,
    052         * Location)} that defaults the values for several parameters. This is used in most cases. The default binding
    053         * prefix will be "prop". Most often, this is used to create a new default binding.
    054         *
    055         * @param description   description of the binding, such as "parameter foo"
    056         * @param container     typically, the parent of the component. This value will be used as the container
    057         *                      <em>and</em> the component, so whatever type of expression is evaluated, will be evaulated
    058         *                      in terms of this component
    059         * @param defaultPrefix the default prefix used when the expression itself does not have a prefix
    060         * @param expression    the binding
    061         * @return a binding
    062         */
    063        Binding newBinding(String description, ComponentResources container, String defaultPrefix, String expression);
    064    }