bundles/org.simantics.db.layer0/src/org/simantics/db/layer0/util/RemoverUtil.java

   1 /*******************************************************************************\r
   2  * Copyright (c) 2007, 2010 Association for Decentralized Information Management\r
   3  * in Industry THTH ry.\r
   4  * All rights reserved. This program and the accompanying materials\r
   5  * are made available under the terms of the Eclipse Public License v1.0\r
   6  * which accompanies this distribution, and is available at\r
   7  * http://www.eclipse.org/legal/epl-v10.html\r
   8  *\r
   9  * Contributors:\r
  10  *     VTT Technical Research Centre of Finland - initial API and implementation\r
  11  *******************************************************************************/\r
  12 package org.simantics.db.layer0.util;\r
  13 \r
  14 import java.util.ArrayList;\r
  15 import java.util.Collection;\r
  16 import java.util.HashMap;\r
  17 import java.util.HashSet;\r
  18 import java.util.List;\r
  19 import java.util.Map;\r
  20 import java.util.Set;\r
  21 import java.util.TreeSet;\r
  22 \r
  23 import org.simantics.db.ReadGraph;\r
  24 import org.simantics.db.Resource;\r
  25 import org.simantics.db.WriteGraph;\r
  26 import org.simantics.db.common.CommentMetadata;\r
  27 import org.simantics.db.common.request.UniqueRead;\r
  28 import org.simantics.db.common.request.WriteRequest;\r
  29 import org.simantics.db.common.request.WriteResultRequest;\r
  30 import org.simantics.db.common.utils.NameUtils;\r
  31 import org.simantics.db.exception.DatabaseException;\r
  32 import org.simantics.db.layer0.adapter.Remover;\r
  33 import org.simantics.db.layer0.adapter.impl.AbstractRemover;\r
  34 import org.simantics.db.layer0.adapter.impl.EntityRemover;\r
  35 import org.simantics.db.layer0.exception.CannotRemoveException;\r
  36 import org.simantics.db.layer0.internal.SimanticsInternal;\r
  37 import org.simantics.utils.strings.AlphanumComparator;\r
  38 import org.simantics.utils.strings.EString;\r
  39 \r
  40 /**\r
  41  * Utility for working with {@link Remover}s.\r
  42  * \r
  43  * @author Tuukka Lehtonen\r
  44  * \r
  45  * @see Remover\r
  46  * @see AbstractRemover\r
  47  */\r
  48 public final class RemoverUtil {\r
  49 \r
  50         public static boolean canRemove(ReadGraph graph, Resource resource) throws DatabaseException {\r
  51         Remover remover = RemoverUtil.getPossibleRemover(graph, resource);\r
  52         if (remover != null) {\r
  53             String problem = remover.canRemove(graph, new HashMap<Object, Object>(4));\r
  54             if (problem != null) return false;\r
  55         }\r
  56         return true;\r
  57         }\r
  58         \r
  59     public static void remove(WriteGraph graph, Resource resource) throws DatabaseException {\r
  60         if (!tryRemover(graph, resource))\r
  61             EntityRemover.remove(graph, resource, true);\r
  62     }\r
  63 \r
  64     public static boolean tryRemover(WriteGraph graph, Resource resource) throws DatabaseException {\r
  65         Remover remover = getPossibleRemover(graph, resource);\r
  66         if (remover != null) {\r
  67             remover.remove(graph);\r
  68             return true;\r
  69         }\r
  70         return false;\r
  71     }\r
  72 \r
  73     /**\r
  74      * @param graph\r
  75      * @param resource\r
  76      * @return\r
  77      * @throws DatabaseException\r
  78      * @since 1.6\r
  79      */\r
  80     public static Remover getPossibleRemover(ReadGraph graph, Resource resource) throws DatabaseException {\r
  81         return graph.getPossibleAdapter(resource, Remover.class);\r
  82     }\r
  83 \r
  84     public static String testRemoval(final Collection<Resource> rs) throws DatabaseException {\r
  85         return SimanticsInternal.getSession().syncRequest(new UniqueRead<String>() {\r
  86             @Override\r
  87             public String perform(ReadGraph graph) throws DatabaseException {\r
  88                 return testRemoval(graph, rs, null);\r
  89             }\r
  90         });\r
  91     }\r
  92 \r
  93     public static String testRemoval(ReadGraph graph, final Collection<Resource> rs, List<Remover> removers) throws DatabaseException {\r
  94         if (removers == null)\r
  95             removers = new ArrayList<Remover>(rs.size());\r
  96 \r
  97         for (Resource r : rs) {\r
  98             Remover remover = graph.getPossibleAdapter(r, Remover.class);\r
  99             if (remover != null)\r
 100                 removers.add(remover);\r
 101         }\r
 102 \r
 103         Map<Object, Object> aux = new HashMap<Object, Object>();\r
 104         List<String> errors = new ArrayList<String>(2);\r
 105         for (Remover remover : removers) {\r
 106             String error = remover.canRemove(graph, aux);\r
 107             if (error != null)\r
 108                 errors.add(error);\r
 109         }\r
 110         if (!errors.isEmpty()) {\r
 111             return EString.implode(errors);\r
 112         }\r
 113 \r
 114         return null;\r
 115     }\r
 116 \r
 117     public static String testRemoval(ReadGraph graph, final Collection<Resource> rs) throws DatabaseException {\r
 118         return testRemoval(graph, rs, null);\r
 119     }\r
 120 \r
 121     public static String checkedRemoval(final Collection<Resource> rs) throws DatabaseException {\r
 122         String problems = testRemoval(rs);\r
 123         if (problems != null) return problems; \r
 124 \r
 125         SimanticsInternal.getSession().syncRequest(new WriteRequest() {\r
 126 \r
 127             @Override\r
 128             public void perform(WriteGraph graph) throws DatabaseException {\r
 129                 CommentMetadata cm = graph.getMetadata(CommentMetadata.class);\r
 130                 for (Resource r : rs) {\r
 131                     // Add comment to change set.\r
 132                     graph.addMetadata(cm.add("Removing " + r + "."));\r
 133                 }\r
 134 \r
 135                 List<Remover> removers = new ArrayList<Remover>(rs.size());\r
 136                 String error = testRemoval(graph, rs, removers);\r
 137                 if (error != null)\r
 138                     throw new CannotRemoveException(error);\r
 139 \r
 140                 for (Remover remover : removers)\r
 141                     remover.remove(graph);\r
 142             }\r
 143 \r
 144         });\r
 145 \r
 146         return null;\r
 147     }\r
 148 \r
 149     /**\r
 150      * Try to remove the provided collection of resources. Removal will commence\r
 151      * only if all resources in the provided collection have the exact same\r
 152      * principal types.\r
 153      * \r
 154      * @param rs\r
 155      *            collection of resources to remove in one go\r
 156      * @return <code>true</code> if removal was successful or <code>false</code>\r
 157      *         if the principal types of all resources in the provided\r
 158      *         collection did not match\r
 159      * @throws CannotRemoveException\r
 160      *             if removal cannot commence because at least one of the\r
 161      *             {@link Remover} instances adapted from the provided resource\r
 162      *             set succeeds.\r
 163      * @throws DatabaseException\r
 164      */\r
 165     public static boolean tryCollectionRemover(final Collection<Resource> rs) throws DatabaseException {\r
 166         return SimanticsInternal.getSession().syncRequest(new WriteResultRequest<Boolean>() {\r
 167             @Override\r
 168             public Boolean perform(WriteGraph graph) throws DatabaseException {\r
 169                 graph.markUndoPoint();\r
 170                 // 1. make sure that all resources are of the same type\r
 171                 Collection<Resource> principalTypes = null;\r
 172                 for (Resource r : rs) {\r
 173                     Collection<Resource> pts = graph.getPrincipalTypes(r);\r
 174                     if (principalTypes == null) {\r
 175                         principalTypes = pts;\r
 176                     } else if (!principalTypes.equals(pts)) {\r
 177                         //return false;\r
 178                         StringBuilder sb = new StringBuilder();\r
 179                         sb.append("Removing resources of different types at the same time is currently not supported.\n\nThe selection contained resources of the following types:\n");\r
 180                         Set<Resource> differentTypes = new HashSet<Resource>();\r
 181                         Set<String> typeNames = new TreeSet<String>(AlphanumComparator.CASE_INSENSITIVE_COMPARATOR);\r
 182                         for (Resource t : rs)\r
 183                             differentTypes.addAll(graph.getPrincipalTypes(t));\r
 184                         for (Resource t : differentTypes)\r
 185                             typeNames.add(NameUtils.getSafeName(graph, t));\r
 186                         for (String typeName : typeNames)\r
 187                             sb.append("\t").append(typeName).append("\n");\r
 188                         throw new CannotRemoveException(sb.toString());\r
 189                     }\r
 190                 }\r
 191 \r
 192                 List<Remover> removers = new ArrayList<Remover>();\r
 193                 Map<Remover, String> removedResources = new HashMap<Remover, String>();\r
 194                 for (Resource r : rs) {\r
 195                     Remover remover = graph.getPossibleAdapter(r, Remover.class);\r
 196                     if (remover != null) {\r
 197                         removers.add(remover);\r
 198                         removedResources.put(remover, NameUtils.getSafeName(graph, r, true));\r
 199                     }\r
 200                 }\r
 201 \r
 202                 Map<Object, Object> aux = new HashMap<Object, Object>();\r
 203                 List<String> errors = new ArrayList<String>(removers.size());\r
 204                 for (Remover remover : removers) {\r
 205                     String error = remover.canRemove(graph, aux);\r
 206                     if (error != null)\r
 207                         errors.add(error);\r
 208                 }\r
 209                 if (!errors.isEmpty()) {\r
 210                     throw new CannotRemoveException(EString.implode(errors));\r
 211                 }\r
 212 \r
 213                 CommentMetadata cm = graph.getMetadata(CommentMetadata.class);\r
 214                 for (Remover remover : removers) {\r
 215                     remover.remove(graph);\r
 216                     graph.addMetadata(cm.add("Removed " + removedResources.get(remover) + "."));\r
 217                 }\r
 218 \r
 219                 return true;\r
 220             }\r
 221         });\r
 222     }\r
 223 \r
 224 }\r