    001// Copyright 2007-2013 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.tapestry5.services;
    016
    017import org.apache.tapestry5.MarkupWriter;
    018
    019/**
    020 * Filter interface for {@link org.apache.tapestry5.services.MarkupRenderer}, which allows for code to execute before
    021 * and/or after the main rendering process. Typically, this is to allow for the placement of
    022 * {@linkplain org.apache.tapestry5.services.Environment environmental services}.
    023 *
    024 * @see org.apache.tapestry5.modules.TapestryModule#contributeMarkupRenderer
    025 */
    026public interface MarkupRendererFilter
    027{
    028    /**
    029     * Implementations should perform work before or after passing the writer to the renderer.
    030     *
    031     * @param writer
    032     *            to which markup should be written
    033     * @param renderer
    034     *            delegate to which the writer should be passed.
    035     */
    036    void renderMarkup(MarkupWriter writer, MarkupRenderer renderer);
    037}