Add file based rule provider and YAML rule parser

Signed-off-by: Ravi Nadahar <nadahar@rediffmail.com>

bundles/org.openhab.core.automation/src/main/java/org/openhab/core/automation/internal/parser/jackson/RuleYAMLParser.java

@@ -0,0 +1,68 @@
+/*
+ * Copyright (c) 2010-2025 Contributors to the openHAB project
+ *
+ * See the NOTICE file(s) distributed with this work for additional
+ * information.
+ *
+ * This program and the accompanying materials are made available under the
+ * terms of the Eclipse Public License 2.0 which is available at
+ * http://www.eclipse.org/legal/epl-2.0
+ *
+ * SPDX-License-Identifier: EPL-2.0
+ */
+package org.openhab.core.automation.internal.parser.jackson;
+
+import java.io.IOException;
+import java.io.InputStreamReader;
+import java.util.HashSet;
+import java.util.List;
+import java.util.Set;
+
+import org.eclipse.jdt.annotation.NonNullByDefault;
+import org.openhab.core.automation.Rule;
+import org.openhab.core.automation.dto.RuleDTO;
+import org.openhab.core.automation.dto.RuleDTOMapper;
+import org.openhab.core.automation.parser.Parser;
+import org.openhab.core.automation.parser.ParsingException;
+import org.openhab.core.automation.parser.ParsingNestedException;
+import org.osgi.service.component.annotations.Component;
+
+import com.fasterxml.jackson.core.type.TypeReference;
+import com.fasterxml.jackson.databind.JsonNode;
+
+/**
+ * This class can parse and serialize sets of {@link Rule}s.
+ *
+ * @author Ravi Nadahar - Initial contribution
+ */
+@NonNullByDefault
+@Component(immediate = true, service = Parser.class, property = { "parser.type=parser.rule", "format=yaml" })
+public class RuleYAMLParser extends AbstractJacksonYAMLParser<Rule> {
+
+    @Override
+    public Set<Rule> parse(InputStreamReader reader) throws ParsingException {
+        try {
+            Set<Rule> rules = new HashSet<>();
+            JsonNode rootNode = yamlMapper.readTree(reader);
+            if (rootNode.isArray()) {
+                List<RuleDTO> ruleDtos = yamlMapper.convertValue(rootNode, new TypeReference<List<RuleDTO>>() {
+                });
+                for (RuleDTO ruleDTO : ruleDtos) {
+                    rules.add(RuleDTOMapper.map(ruleDTO));
+                }
+            } else {
+                RuleDTO ruleDto = yamlMapper.convertValue(rootNode, new TypeReference<RuleDTO>() {
+                });
+                rules.add(RuleDTOMapper.map(ruleDto));
+            }
+            return rules;
+        } catch (Exception e) {
+            throw new ParsingException(new ParsingNestedException(ParsingNestedException.RULE, null, e));
+        } finally {
+            try {
+                reader.close();
+            } catch (IOException e) {
+            }
+        }
+    }
+}

bundles/org.openhab.core.automation/src/main/java/org/openhab/core/automation/internal/provider/file/AbstractFileProvider.java

@@ -225,6 +225,7 @@ public void removeParser(Parser<E> parser, Map<String, String> properties) {
      * @param url a specified URL for import.
      */
     protected void importFile(String parserType, URL url) {
+        logger.debug("Reading file \"{}\"", url);
         Parser<E> parser = parsers.get(parserType);
         if (parser != null) {
             InputStream is = null;
@@ -258,7 +259,7 @@ protected void importFile(String parserType, URL url) {
                 List<URL> value = Objects.requireNonNull(urls.computeIfAbsent(parserType, k -> new ArrayList<>()));
                 value.add(url);
             }
-            logger.debug("Parser {} not available", parserType, new Exception());
+            logger.debug("Couldn't parse \"{}\", no \"{}\" parser available", url, parserType);
         }
     }
 

bundles/org.openhab.core.automation/src/main/java/org/openhab/core/automation/internal/provider/file/RuleFileProvider.java

@@ -0,0 +1,47 @@
+/*
+ * Copyright (c) 2010-2025 Contributors to the openHAB project
+ *
+ * See the NOTICE file(s) distributed with this work for additional
+ * information.
+ *
+ * This program and the accompanying materials are made available under the
+ * terms of the Eclipse Public License 2.0 which is available at
+ * http://www.eclipse.org/legal/epl-2.0
+ *
+ * SPDX-License-Identifier: EPL-2.0
+ */
+package org.openhab.core.automation.internal.provider.file;
+
+import java.util.Collection;
+import java.util.List;
+
+import org.eclipse.jdt.annotation.NonNullByDefault;
+import org.openhab.core.automation.Rule;
+import org.openhab.core.automation.RuleProvider;
+
+/**
+ * This class is a {@link RuleProvider} implementation that provides file-based rules. It extends the functionality
+ * of {@link AbstractFileProvider} for importing the {@link Rule}s from local files.
+ *
+ * @author Ravi Nadahar - Initial contribution
+ */
+@NonNullByDefault
+public abstract class RuleFileProvider extends AbstractFileProvider<Rule> implements RuleProvider {
+
+    /**
+     * Creates a new instance.
+     */
+    public RuleFileProvider() {
+        super("rules");
+    }
+
+    @Override
+    protected String getUID(Rule providedObject) {
+        return providedObject.getUID();
+    }
+
+    @Override
+    public Collection<Rule> getAll() {
+        return List.copyOf(providedObjectsHolder.values());
+    }
+}

bundles/org.openhab.core.automation/src/main/java/org/openhab/core/automation/internal/provider/file/RuleFileProviderWatcher.java

@@ -0,0 +1,85 @@
+/*
+ * Copyright (c) 2010-2025 Contributors to the openHAB project
+ *
+ * See the NOTICE file(s) distributed with this work for additional
+ * information.
+ *
+ * This program and the accompanying materials are made available under the
+ * terms of the Eclipse Public License 2.0 which is available at
+ * http://www.eclipse.org/legal/epl-2.0
+ *
+ * SPDX-License-Identifier: EPL-2.0
+ */
+package org.openhab.core.automation.internal.provider.file;
+
+import java.util.Map;
+
+import org.eclipse.jdt.annotation.NonNullByDefault;
+import org.openhab.core.OpenHAB;
+import org.openhab.core.automation.Rule;
+import org.openhab.core.automation.RuleProvider;
+import org.openhab.core.automation.parser.Parser;
+import org.openhab.core.automation.parser.ValidationException;
+import org.openhab.core.automation.parser.ValidationException.ObjectType;
+import org.openhab.core.service.WatchService;
+import org.osgi.service.component.annotations.Activate;
+import org.osgi.service.component.annotations.Component;
+import org.osgi.service.component.annotations.Reference;
+import org.osgi.service.component.annotations.ReferenceCardinality;
+import org.osgi.service.component.annotations.ReferencePolicy;
+
+/**
+ * This class is a wrapper of {@link RuleFileProvider}s, responsible for initializing the WatchService.
+ *
+ * @author Ravi Nadahar - Initial contribution
+ */
+@NonNullByDefault
+@Component(immediate = true, service = RuleProvider.class)
+public class RuleFileProviderWatcher extends RuleFileProvider {
+
+    private final WatchService watchService;
+
+    /**
+     * Creates a new instance using the specified watch service.
+     *
+     * @param watchService the {@link WatchService} to use.
+     */
+    @Activate
+    public RuleFileProviderWatcher(@Reference(target = WatchService.CONFIG_WATCHER_FILTER) WatchService watchService) {
+        this.watchService = watchService;
+        configurationRoots = new String[] { OpenHAB.getConfigFolder() };
+    }
+
+    @Override
+    protected void initializeWatchService(String watchingDir) {
+        WatchServiceUtil.initializeWatchService(watchingDir, this, watchService);
+    }
+
+    @Override
+    protected void deactivateWatchService(String watchingDir) {
+        WatchServiceUtil.deactivateWatchService(watchingDir, this);
+    }
+
+    @Reference(cardinality = ReferenceCardinality.AT_LEAST_ONE, policy = ReferencePolicy.DYNAMIC, target = "(parser.type=parser.rule)")
+    @Override
+    public void addParser(Parser<Rule> parser, Map<String, String> properties) {
+        super.addParser(parser, properties);
+    }
+
+    @Override
+    public void removeParser(Parser<Rule> parser, Map<String, String> properties) {
+        super.removeParser(parser, properties);
+    }
+
+    @SuppressWarnings("null")
+    @Override
+    protected void validateObject(Rule rule) throws ValidationException {
+        String s;
+        if ((s = rule.getUID()) == null || s.isBlank()) {
+            throw new ValidationException(ObjectType.RULE, null, "UID cannot be blank");
+        }
+        if ((s = rule.getName()) == null || s.isBlank()) {
+            throw new ValidationException(ObjectType.RULE, rule.getUID(), "Name cannot be blank");
+        }
+    }
+}