001/* 002 * (C) Copyright 2006-2007 Nuxeo SA (http://nuxeo.com/) and others. 003 * 004 * Licensed under the Apache License, Version 2.0 (the "License"); 005 * you may not use this file except in compliance with the License. 006 * You may obtain a copy of the License at 007 * 008 * http://www.apache.org/licenses/LICENSE-2.0 009 * 010 * Unless required by applicable law or agreed to in writing, software 011 * distributed under the License is distributed on an "AS IS" BASIS, 012 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 013 * See the License for the specific language governing permissions and 014 * limitations under the License. 015 * 016 * Contributors: 017 * Jean-Marc Orliaguet, Chalmers 018 * 019 * $Id$ 020 */ 021 022package org.nuxeo.theme.negotiation; 023 024import java.util.List; 025 026import javax.servlet.http.HttpServletRequest; 027 028import org.nuxeo.theme.Manager; 029import org.nuxeo.theme.types.TypeFamily; 030 031public abstract class AbstractNegotiator implements Negotiator { 032 033 private static final String SPEC_PREFIX = "nxtheme://theme"; 034 035 // FIXME: can be called 'web' under webengine 036 private static final String DEFAULT_NEGOTIATION_STRATEGY = "default"; 037 038 protected final String strategy; 039 040 protected final Object context; 041 042 protected final HttpServletRequest request; 043 044 public abstract String getTemplateEngineName(); 045 046 protected AbstractNegotiator(String strategy, Object context, HttpServletRequest request) { 047 this.strategy = strategy; 048 this.context = context; 049 this.request = request; 050 } 051 052 public final String getSpec() throws NegotiationException { 053 return String.format("%s/%s/%s/%s/%s/%s/%s", SPEC_PREFIX, negotiate("engine"), negotiate("mode"), 054 getTemplateEngineName(), negotiate("theme"), negotiate("perspective"), negotiate("collection")); 055 } 056 057 public final synchronized String negotiate(String object) throws NegotiationException { 058 if (strategy == null) { 059 throw new NegotiationException("No negotiation strategy is set."); 060 } 061 NegotiationType negotiation = (NegotiationType) Manager.getTypeRegistry().lookup(TypeFamily.NEGOTIATION, 062 String.format("%s/%s", strategy, object)); 063 // Try with the 'default' strategy 064 if (negotiation == null) { 065 negotiation = (NegotiationType) Manager.getTypeRegistry().lookup(TypeFamily.NEGOTIATION, 066 String.format("%s/%s", DEFAULT_NEGOTIATION_STRATEGY, object)); 067 } 068 if (negotiation == null) { 069 throw new NegotiationException("Could not obtain negotiation for: " + strategy + " (strategy) " + object 070 + " (object)"); 071 } 072 final List<Scheme> schemes = negotiation.getSchemes(); 073 074 String outcome = null; 075 if (schemes != null) { 076 for (Scheme scheme : negotiation.getSchemes()) { 077 outcome = scheme.getOutcome(context); 078 if (outcome != null) { 079 break; 080 } 081 } 082 } 083 if (outcome == null) { 084 throw new NegotiationException("No negotiation outcome found for: " + strategy + " (strategy) " + object 085 + " (object)"); 086 } else { 087 // add result to the request 088 request.setAttribute(NEGOTIATION_RESULT_PREFIX + object, outcome); 089 } 090 return outcome; 091 } 092}