001/*
002 * Licensed to the Apache Software Foundation (ASF) under one or more
003 * contributor license agreements.  See the NOTICE file distributed with
004 * this work for additional information regarding copyright ownership.
005 * The ASF licenses this file to You under the Apache License, Version 2.0
006 * (the "License"); you may not use this file except in compliance with
007 * the License.  You may obtain a copy of the License at
008 *
009 *      http://www.apache.org/licenses/LICENSE-2.0
010 *
011 * Unless required by applicable law or agreed to in writing, software
012 * distributed under the License is distributed on an "AS IS" BASIS,
013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
014 * See the License for the specific language governing permissions and
015 * limitations under the License.
016 */
017package org.apache.wicket.csp;
018
019import org.apache.wicket.request.cycle.RequestCycle;
020
021/**
022 * {@code CSPRenderable} describes a directive that is part of a Content-Security-Policy (CSP in
023 * short). Most directives are predefined in enums.
024 * 
025 * @author papegaaij
026 * @see CSPDirectiveSrcValue
027 * @see CSPDirectiveSandboxValue
028 * @see FixedCSPValue
029 */
030public interface CSPRenderable
031{
032        /**
033         * Renders the value that should be put in the CSP header.
034         * 
035         * @param settings
036         *            The {@link ContentSecurityPolicySettings} that renders this value.
037         * @param cycle
038         *            The current {@link RequestCycle}.
039         * @return The rendered value.
040         */
041        String render(ContentSecurityPolicySettings settings, RequestCycle cycle);
042        
043        /**
044         * Checks if the {@code CSPRenderable} represents a valid value for a {@code -src} directive. By
045         * default no checks are performed.
046         * 
047         * @throws IllegalStateException
048         *             when this {@code CSPRenderable} represents an invalid value.
049         */
050        default void checkValidityForSrc()
051        {
052        }
053}