gerrit.simantics Code Review - simantics/platform.git/blob

   1 /*******************************************************************************
   2  * Copyright (c) 2007, 2010 Association for Decentralized Information Management
   3  * in Industry THTH ry.
   4  * All rights reserved. This program and the accompanying materials
   5  * are made available under the terms of the Eclipse Public License v1.0
   6  * which accompanies this distribution, and is available at
   7  * http://www.eclipse.org/legal/epl-v10.html
   8  *
   9  * Contributors:
  10  *     VTT Technical Research Centre of Finland - initial API and implementation
  11  *******************************************************************************/
  12 package org.simantics.ui.workbench.editor.input;
  13
  14 import java.util.Arrays;
  15
  16 import org.simantics.db.ReadGraph;
  17 import org.simantics.db.Resource;
  18 import org.simantics.db.common.request.ParametrizedRead;
  19 import org.simantics.db.common.request.Queries;
  20 import org.simantics.db.common.request.UnaryRead;
  21 import org.simantics.db.exception.DatabaseException;
  22 import org.simantics.db.layer0.request.combinations.Combinators;
  23 import org.simantics.db.layer0.request.combinations.Combinators.SynchronizationProcedure;
  24 import org.simantics.db.request.Read;
  25 import org.simantics.ui.workbench.IResourceEditorInput;
  26
  27 /**
  28  * Composable database read operations designed to be used for defining
  29  * validation strategies for resource editor inputs through composition.
  30  *
  31  * <p>
  32  * For example one validation criterion might be that the editor input or one of
  33  * its neighboring resources must have a proper URI.
  34  *
  35  * @author Tuukka Lehtonen
  36  */
  37 public final class InputValidationCombinators {
  38
  39     /**
  40      * Returns a function:
  41      * <pre>
  42      *   = subject -> exists(URI(subject))
  43      *   | null    -> false
  44      * </pre>.
  45      */
  46     public static ParametrizedRead<Resource, Boolean> hasURI() {
  47         return HAS_URI;
  48     }
  49
  50     /**
  51      * Returns a function:
  52      * <pre>
  53      *   = input -> resource(input)
  54      *   | null  -> null
  55      * </pre>.
  56      */
  57     public static ParametrizedRead<IResourceEditorInput, Resource> extractInputResource() {
  58         return EXTRACT_INPUT_RESOURCE;
  59     }
  60
  61     /**
  62      * Returns a function:
  63      * <pre>
  64      *   = subject -> singleObject(subject, resource(relationURI))
  65      *   | null    -> null
  66      * </pre>.
  67      */
  68     public static ParametrizedRead<Resource,Resource> completeFunction(String relationURI) {
  69         return new CompleteFunctionURI(relationURI);
  70     }
  71
  72     /**
  73      * Returns a function:
  74      * <pre>
  75      *   = subject -> possibleObject(subject, resource(relationURI))
  76      *   | null    -> null
  77      * </pre>.
  78      */
  79     public static ParametrizedRead<Resource,Resource> partialFunction(String relationURI) {
  80         return new PartialFunctionURI(relationURI);
  81     }
  82
  83     /**
  84      * Returns a function:
  85      * <pre>
  86      *   = subject -> true if any of conditions is true for subject, false otherwise
  87      *   | null    -> true
  88      * </pre>.
  89      */
  90     @SuppressWarnings("unchecked")
  91     public static ParametrizedRead<Resource, Boolean> or(ParametrizedRead<Resource, Boolean> c1,
  92             ParametrizedRead<Resource, Boolean> c2) {
  93         return new FunctionOr(new ParametrizedRead[] { c1, c2 });
  94     }
  95
  96     // ------------------------------------------------------------------------
  97
  98     private static class Or extends UnaryRead<Resource, Boolean> {
  99         ParametrizedRead<Resource, Boolean>[] reads;
 100         public Or(Resource resource, ParametrizedRead<Resource, Boolean>... reads) {
 101             super(resource);
 102             this.reads = reads;
 103         }
 104         @Override
 105         public Boolean perform(ReadGraph graph) throws DatabaseException {
 106             for (ParametrizedRead<Resource, Boolean> r : reads) {
 107                 Read<Boolean> read = r.get(parameter);
 108                 Boolean value = graph.syncRequest( read );
 109                 if (value)
 110                     return Boolean.TRUE;
 111             }
 112             return Boolean.FALSE;
 113         }
 114         @Override
 115         public int hashCode() {
 116             return super.hashCode() * 31 + Arrays.hashCode(reads);
 117         }
 118         @Override
 119         public boolean equals(Object object) {
 120             if (this == object) return true;
 121             else if (object == null || getClass() != object.getClass()) return false;
 122             Or other = (Or) object;
 123             return super.equals(object) && Arrays.equals(reads, other.reads);
 124         }
 125     }
 126
 127     // ------------------------------------------------------------------------
 128
 129     private static class FunctionOr implements ParametrizedRead<Resource, Boolean> {
 130         ParametrizedRead<Resource, Boolean>[] reads;
 131         public FunctionOr(ParametrizedRead<Resource, Boolean>... reads) {
 132             this.reads = reads;
 133         }
 134         @Override
 135         public Read<Boolean> get(Resource subject) {
 136             if (subject == null || reads.length == 0)
 137                 return Combinators.constant(Boolean.TRUE);
 138             return new Or(subject, reads);
 139         }
 140         @Override
 141         public int hashCode() {
 142             return getClass().hashCode() + 31 * Arrays.hashCode(reads);
 143         }
 144         @Override
 145         public boolean equals(Object obj) {
 146             if(obj == this) return true;
 147             if(obj == null || obj.getClass() != getClass()) return false;
 148             FunctionOr other = (FunctionOr)obj;
 149             return Arrays.equals(reads, other.reads);
 150         }
 151     }
 152
 153     // ------------------------------------------------------------------------
 154
 155     private static class HasURI extends UnaryRead<Resource, Boolean> {
 156         public HasURI(Resource resource) {
 157             super(resource);
 158         }
 159         @Override
 160         public Boolean perform(ReadGraph graph) throws DatabaseException {
 161             if (parameter == null)
 162                 return Boolean.FALSE;
 163
 164             String uri = graph.syncRequest(Queries.possibleUri(parameter));
 165             //System.out.println("uri(" + parameter + "): " + uri);
 166             if (uri == null)
 167                 return Boolean.FALSE;
 168
 169             // FIXME: URI request will return invalid URIs, like
 170             // null/Configuration/MyComposite after deleting the parenting model
 171             // For this reason we try to reverse lookup the URI back into a
 172             // resource which must be equal to the original parameter resource.
 173
 174             Resource reverseLookup = graph.getPossibleResource(uri);
 175             //System.out.println("resource(" + uri + "): " + reverseLookup);
 176             return parameter.equals(reverseLookup);
 177         }
 178     }
 179
 180     public static Read<Boolean> hasURI(Resource resource) {
 181         return new HasURI(resource);
 182     }
 183
 184     // ------------------------------------------------------------------------
 185
 186     private static class ExtractResource extends UnaryRead<IResourceEditorInput, Resource> {
 187         public ExtractResource(IResourceEditorInput input) {
 188             super(input);
 189         }
 190         @Override
 191         public Resource perform(ReadGraph graph) throws DatabaseException {
 192             return parameter != null ? parameter.getResource() : null;
 193         }
 194     }
 195
 196     public static Read<Resource> extractResource(IResourceEditorInput input) {
 197         return new ExtractResource(input);
 198     }
 199
 200     // ------------------------------------------------------------------------
 201
 202     private static class PossibleObjectURI implements Read<Resource> {
 203         Resource subject;
 204         String relationURI;
 205         public PossibleObjectURI(Resource subject, String relationURI) {
 206             this.subject = subject;
 207             this.relationURI = relationURI;
 208         }
 209         @Override
 210         public Resource perform(ReadGraph graph) throws DatabaseException {
 211             SynchronizationProcedure<Resource> procedure = new SynchronizationProcedure<Resource>();
 212             Resource relation = graph.getResource(relationURI);
 213             graph.forPossibleObject(subject, relation, procedure);
 214             return procedure.getResult();
 215         }
 216         @Override
 217         public int hashCode() {
 218             return subject.hashCode() + 31 * relationURI.hashCode();
 219         }
 220         @Override
 221         public boolean equals(Object object) {
 222             if (this == object) return true;
 223             else if (object == null || getClass() != object.getClass()) return false;
 224             PossibleObjectURI other = (PossibleObjectURI)object;
 225             return subject.equals(other.subject) && relationURI.equals(other.relationURI);
 226         }
 227     }
 228
 229     /**
 230      * Returns a read request that reads an object possibly connected to the subject by the relation.
 231      */
 232     public static Read<Resource> possibleObject(Resource subject, String relationURI) {
 233         return new PossibleObjectURI(subject, relationURI);
 234     }
 235
 236     // ------------------------------------------------------------------------
 237
 238     private static class PartialFunctionURI implements ParametrizedRead<Resource, Resource> {
 239         String relationURI;
 240         public PartialFunctionURI(String relationURI) {
 241             this.relationURI = relationURI;
 242         }
 243         @Override
 244         public Read<Resource> get(Resource subject) {
 245             if (subject == null)
 246                 return Combinators.constant(null);
 247             return possibleObject(subject, relationURI);
 248         }
 249         @Override
 250         public int hashCode() {
 251             return getClass().hashCode() + 31 * relationURI.hashCode();
 252         }
 253         @Override
 254         public boolean equals(Object obj) {
 255             if(obj == this) return true;
 256             if(obj == null || obj.getClass() != getClass()) return false;
 257             PartialFunctionURI other = (PartialFunctionURI)obj;
 258             return relationURI.equals(other.relationURI);
 259         }
 260     }
 261
 262     // ------------------------------------------------------------------------
 263
 264     private static class SingleObjectURI implements Read<Resource> {
 265         Resource subject;
 266         String relationURI;
 267         public SingleObjectURI(Resource subject, String relationURI) {
 268             this.subject = subject;
 269             this.relationURI = relationURI;
 270         }
 271         @Override
 272         public Resource perform(ReadGraph graph) throws DatabaseException {
 273             SynchronizationProcedure<Resource> procedure = new SynchronizationProcedure<Resource>();
 274             Resource relation = graph.getResource(relationURI);
 275             graph.forSingleObject(subject, relation, procedure);
 276             return procedure.getResult();
 277         }
 278         @Override
 279         public int hashCode() {
 280             return subject.hashCode() + 31 * relationURI.hashCode();
 281         }
 282         @Override
 283         public boolean equals(Object object) {
 284             if (this == object) return true;
 285             else if (object == null || getClass() != object.getClass()) return false;
 286             SingleObjectURI other = (SingleObjectURI) object;
 287             return subject.equals(other.subject) && relationURI.equals(other.relationURI);
 288         }
 289     }
 290
 291     /**
 292      * Returns a read request that reads a single object connected to the
 293      * subject by the relation.
 294      */
 295     public static Read<Resource> singleObject(Resource subject, String relationURI) {
 296         return new SingleObjectURI(subject, relationURI);
 297     }
 298
 299     // ------------------------------------------------------------------------
 300
 301     private static class CompleteFunctionURI implements ParametrizedRead<Resource, Resource> {
 302         String relationURI;
 303         public CompleteFunctionURI(String relationURI) {
 304             this.relationURI = relationURI;
 305         }
 306         @Override
 307         public Read<Resource> get(Resource subject) {
 308             if (subject == null)
 309                 return Combinators.constant(null);
 310             return singleObject(subject, relationURI);
 311         }
 312         @Override
 313         public int hashCode() {
 314             return getClass().hashCode() + 31 * relationURI.hashCode();
 315         }
 316         @Override
 317         public boolean equals(Object obj) {
 318             if(obj == this) return true;
 319             if(obj == null || obj.getClass() != getClass()) return false;
 320             CompleteFunctionURI other = (CompleteFunctionURI)obj;
 321             return relationURI.equals(other.relationURI);
 322         }
 323     }
 324
 325     // ------------------------------------------------------------------------
 326
 327     private static final ParametrizedRead<IResourceEditorInput, Resource> EXTRACT_INPUT_RESOURCE = new ParametrizedRead<IResourceEditorInput, Resource>() {
 328         @Override
 329         public Read<Resource> get(IResourceEditorInput input) {
 330             return extractResource(input);
 331         }
 332     };
 333
 334     // ------------------------------------------------------------------------
 335
 336     private static final ParametrizedRead<Resource, Boolean> HAS_URI = new ParametrizedRead<Resource, Boolean>() {
 337         @Override
 338         public Read<Boolean> get(Resource resource) {
 339             return hasURI(resource);
 340         }
 341     };
 342
 343 }