src/web/org/codehaus/groovy/grails/web/converters/ConverterUtil.java

   1 /* Copyright 2006-2007 Graeme Rocher
   2  *
   3  * Licensed under the Apache License, Version 2.0 (the "License");
   4  * you may not use this file except in compliance with the License.
   5  * You may obtain a copy of the License at
   6  *
   7  *      http://www.apache.org/licenses/LICENSE-2.0
   8  *
   9  * Unless required by applicable law or agreed to in writing, software
  10  * distributed under the License is distributed on an "AS IS" BASIS,
  11  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  12  * See the License for the specific language governing permissions and
  13  * limitations under the License.
  14  */
  15 package org.codehaus.groovy.grails.web.converters;
  16
  17 /**
  18  * A utility class for creating and dealing with Converter objects
  19  *
  20  * @author Siegfried Puchbauer
  21  * @since 0.6
  22  */
  23
  24 import com.thoughtworks.xstream.XStream;
  25 import grails.converters.XML;
  26 import groovy.lang.Closure;
  27 import org.apache.commons.logging.Log;
  28 import org.apache.commons.logging.LogFactory;
  29 import org.codehaus.groovy.grails.commons.DomainClassArtefactHandler;
  30 import org.codehaus.groovy.grails.commons.GrailsApplication;
  31 import org.codehaus.groovy.grails.commons.GrailsDomainClass;
  32 import org.codehaus.groovy.grails.web.converters.exceptions.ConverterException;
  33 import org.codehaus.groovy.runtime.DefaultGroovyMethods;
  34
  35 import java.io.File;
  36 import java.util.*;
  37
  38 public class ConverterUtil {
  39
  40     private final static Log log = LogFactory.getLog(ConverterUtil.class);
  41
  42     private static ConverterUtil INSTANCE;
  43
  44     public static Object createConverter(Class converterClass, Object target) throws ConverterException {
  45         try {
  46             AbstractConverter converter = (AbstractConverter) converterClass.newInstance();
  47             converter.setTarget(target);
  48             return converter;
  49         } catch (Exception e) {
  50             throw new ConverterException("Initialization of Converter Object " + converterClass.getName()
  51                     + " failed for target " + target.getClass().getName(), e);
  52         }
  53     }
  54
  55     private static Map XSTREAM_MAP = new HashMap();
  56     private static Map ALIAS_MAP = new HashMap();
  57
  58     public static XStream
  59     getXStream(Class clazz) {
  60         XStream xs = (XStream) XSTREAM_MAP.get(clazz);
  61         if (xs == null) {
  62             xs = setupXStream(clazz);
  63         }
  64         return xs;
  65     }
  66
  67     protected static XStream setupXStream(Class converter) {
  68         XStream xs = new XStream();
  69
  70         xs.setMode(XStream.XPATH_ABSOLUTE_REFERENCES);
  71         for (Iterator iterator = ALIAS_MAP.keySet().iterator(); iterator.hasNext();) {
  72             Class cls = (Class) iterator.next();
  73             String alias = (String) ALIAS_MAP.get(cls);
  74             xs.alias(alias, cls);
  75         }
  76         try {
  77             XML instance = (XML) converter.newInstance();
  78             instance.configureXStream(xs);
  79
  80             XSTREAM_MAP.put(converter, xs);
  81         } catch (Exception e) {
  82             log.error("Error configuring XStream for Converter " + converter.getName(), e);
  83         }
  84         return xs;
  85     }
  86
  87     public static void addAlias(String alias, Class clazz) {
  88         ALIAS_MAP.put(clazz, alias);
  89         XSTREAM_MAP.clear();
  90     }
  91
  92     public static String getAlias(Class cls) {
  93         return (String) ALIAS_MAP.get(cls);
  94     }
  95
  96     public static String resolveAlias(Class cls) {
  97         String alias = (String) ALIAS_MAP.get(cls);
  98         if (alias == null) return cls.getName();
  99         else return alias;
 100     }
 101
 102     public static GrailsDomainClass getDomainClass(String name) {
 103         // deal with proxies
 104         name = trimProxySuffix(name);
 105         return (GrailsDomainClass) getGrailsApplication().getArtefact(DomainClassArtefactHandler.TYPE, name);
 106     }
 107
 108     private static String trimProxySuffix(String name) {
 109         int i = name.indexOf("$$");
 110         if(i > -1) {
 111             name = name.substring(0,i);
 112         }
 113         return name;
 114     }
 115
 116     private static GrailsApplication getGrailsApplication() {
 117         return getInstance().grailsApplication;
 118     }
 119
 120     protected static ConverterUtil getInstance() {
 121         if (INSTANCE == null) {
 122             INSTANCE = new ConverterUtil();
 123         }
 124         return INSTANCE;
 125     }
 126
 127     public static boolean isConverterClass(Class clazz) {
 128         return Converter.class.isAssignableFrom(clazz);
 129     }
 130
 131     public static boolean isDomainClass(Class clazz) {
 132         String name = trimProxySuffix(clazz.getName());
 133         return getGrailsApplication().isArtefactOfType(DomainClassArtefactHandler.TYPE, name);
 134     }
 135
 136     public static Set getDomainClassNames() {
 137         return getGrailsApplication().getArtefactInfo(DomainClassArtefactHandler.TYPE).getClassesByName().keySet();
 138     }
 139
 140     public static void setGrailsApplication(GrailsApplication grailsApp) {
 141         getInstance().grailsApplication = grailsApp;
 142     }
 143
 144     private GrailsApplication grailsApplication;
 145
 146     protected ConverterUtil() {
 147
 148     }
 149
 150     public static Object invokeOriginalAsTypeMethod(Object delegate, Class clazz) {
 151         if (delegate instanceof Collection)
 152             return DefaultGroovyMethods.asType((Collection) delegate, clazz);
 153         else if (delegate instanceof Closure)
 154             return DefaultGroovyMethods.asType((Closure) delegate, clazz);
 155         else if (delegate instanceof Map)
 156             return DefaultGroovyMethods.asType((Map) delegate, clazz);
 157         else if (delegate instanceof Number)
 158             return DefaultGroovyMethods.asType((Number) delegate, clazz);
 159         else if (delegate instanceof File)
 160             return DefaultGroovyMethods.asType((File) delegate, clazz);
 161         else if (delegate instanceof String)
 162             return DefaultGroovyMethods.asType((String) delegate, clazz);
 163         else
 164             return DefaultGroovyMethods.asType(delegate, clazz);
 165     }
 166 }
 167