yang Notification Listener
Change-Id: I1073be0342bee083495e2c103bad8351f492441c
diff --git a/utils/yangutils/src/main/java/org/onosproject/yangutils/parser/impl/listeners/NotificationListener.java b/utils/yangutils/src/main/java/org/onosproject/yangutils/parser/impl/listeners/NotificationListener.java
new file mode 100644
index 0000000..3a87414
--- /dev/null
+++ b/utils/yangutils/src/main/java/org/onosproject/yangutils/parser/impl/listeners/NotificationListener.java
@@ -0,0 +1,162 @@
+/*
+ * Copyright 2016 Open Networking Laboratory
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.onosproject.yangutils.parser.impl.listeners;
+
+import org.onosproject.yangutils.datamodel.YangNotification;
+import org.onosproject.yangutils.datamodel.YangModule;
+import org.onosproject.yangutils.datamodel.YangSubModule;
+import org.onosproject.yangutils.datamodel.YangNode;
+import org.onosproject.yangutils.datamodel.exceptions.DataModelException;
+import org.onosproject.yangutils.parser.Parsable;
+import org.onosproject.yangutils.parser.antlrgencode.GeneratedYangParser;
+import org.onosproject.yangutils.parser.exceptions.ParserException;
+import org.onosproject.yangutils.parser.impl.TreeWalkListener;
+
+import static org.onosproject.yangutils.datamodel.utils.GeneratedLanguage.JAVA_GENERATION;
+import static org.onosproject.yangutils.datamodel.utils.YangDataModelFactory.getYangNotificationNode;
+import static org.onosproject.yangutils.parser.impl.parserutils.ListenerCollisionDetector.detectCollidingChildUtil;
+import static org.onosproject.yangutils.parser.impl.parserutils.ListenerErrorLocation.ENTRY;
+import static org.onosproject.yangutils.parser.impl.parserutils.ListenerErrorLocation.EXIT;
+import static org.onosproject.yangutils.parser.impl.parserutils.ListenerErrorMessageConstruction.constructExtendedListenerErrorMessage;
+import static org.onosproject.yangutils.parser.impl.parserutils.ListenerErrorMessageConstruction.constructListenerErrorMessage;
+import static org.onosproject.yangutils.parser.impl.parserutils.ListenerErrorType.*;
+import static org.onosproject.yangutils.parser.impl.parserutils.ListenerUtil.getValidIdentifier;
+import static org.onosproject.yangutils.parser.impl.parserutils.ListenerValidation.checkStackIsNotEmpty;
+import static org.onosproject.yangutils.parser.impl.parserutils.ListenerValidation.validateCardinalityMaxOne;
+import static org.onosproject.yangutils.parser.impl.parserutils.ListenerValidation.validateMutuallyExclusiveChilds;
+import static org.onosproject.yangutils.utils.YangConstructType.NOTIFICATION_DATA;
+import static org.onosproject.yangutils.utils.YangConstructType.STATUS_DATA;
+import static org.onosproject.yangutils.utils.YangConstructType.DESCRIPTION_DATA;
+import static org.onosproject.yangutils.utils.YangConstructType.REFERENCE_DATA;
+import static org.onosproject.yangutils.utils.YangConstructType.TYPEDEF_DATA;
+import static org.onosproject.yangutils.utils.YangConstructType.GROUPING_DATA;
+
+/*
+ * Reference: RFC6020 and YANG ANTLR Grammar
+ *
+ * ABNF grammar as per RFC6020
+ * notification-stmt = notification-keyword sep
+ * identifier-arg-str optsep
+ * (";" /
+ * "{" stmtsep
+ * ;; these stmts can appear in any order
+ * *(if-feature-stmt stmtsep)
+ * [status-stmt stmtsep]
+ * [description-stmt stmtsep]
+ * [reference-stmt stmtsep]
+ * *((typedef-stmt /
+ * grouping-stmt) stmtsep)
+ * *(data-def-stmt stmtsep)
+ * "}")
+ *
+ * ANTLR grammar rule
+ * notificationStatement : NOTIFICATION_KEYWORD identifier (STMTEND | LEFT_CURLY_BRACE (ifFeatureStatement
+ * | statusStatement | descriptionStatement | referenceStatement | typedefStatement
+ * | groupingStatement | dataDefStatement)* RIGHT_CURLY_BRACE);
+ */
+
+/**
+ * Implements listener based call back function corresponding to the "notification"
+ * rule defined in ANTLR grammar file for corresponding ABNF rule in RFC 6020.
+ */
+public final class NotificationListener {
+
+ /**
+ * Creates a new notification listener.
+ */
+ private NotificationListener() {
+ }
+
+ /**
+ * It is called when parser receives an input matching the grammar rule
+ * (notification), performs validation and updates the data model tree.
+ *
+ * @param listener listener's object
+ * @param ctx context object of the grammar rule
+ */
+ public static void processNotificationEntry(TreeWalkListener listener,
+ GeneratedYangParser.NotificationStatementContext ctx) {
+
+ // Check for stack to be non empty.
+ checkStackIsNotEmpty(listener, MISSING_HOLDER, NOTIFICATION_DATA, ctx.identifier().getText(), ENTRY);
+
+ String identifier = getValidIdentifier(ctx.identifier().getText(), NOTIFICATION_DATA, ctx);
+
+ // Validate sub statement cardinality.
+ validateSubStatementsCardinality(ctx);
+
+ // Check for identifier collision
+ int line = ctx.getStart().getLine();
+ int charPositionInLine = ctx.getStart().getCharPositionInLine();
+ detectCollidingChildUtil(listener, line, charPositionInLine, identifier, NOTIFICATION_DATA);
+
+ Parsable curData = listener.getParsedDataStack().peek();
+ if (curData instanceof YangModule || curData instanceof YangSubModule) {
+
+ YangNotification notification = getYangNotificationNode(JAVA_GENERATION);
+ notification.setName(identifier);
+ YangNode curNode = (YangNode) curData;
+ try {
+ curNode.addChild(notification);
+ } catch (DataModelException e) {
+ throw new ParserException(constructExtendedListenerErrorMessage(UNHANDLED_PARSED_DATA,
+ NOTIFICATION_DATA, ctx.identifier().getText(), ENTRY, e.getMessage()));
+ }
+ listener.getParsedDataStack().push(notification);
+ } else {
+ throw new ParserException(constructListenerErrorMessage(INVALID_HOLDER, NOTIFICATION_DATA,
+ ctx.identifier().getText(), ENTRY));
+ }
+ }
+
+ /**
+ * It is called when parser exits from grammar rule (notification), it perform
+ * validations and updates the data model tree.
+ *
+ * @param listener listener's object
+ * @param ctx context object of the grammar rule
+ */
+ public static void processNotificationExit(TreeWalkListener listener,
+ GeneratedYangParser.NotificationStatementContext ctx) {
+
+ // Check for stack to be non empty.
+ checkStackIsNotEmpty(listener, MISSING_HOLDER, NOTIFICATION_DATA, ctx.identifier().getText(), EXIT);
+
+ if (listener.getParsedDataStack().peek() instanceof YangNotification) {
+ listener.getParsedDataStack().pop();
+ } else {
+ throw new ParserException(constructListenerErrorMessage(MISSING_CURRENT_HOLDER, NOTIFICATION_DATA,
+ ctx.identifier().getText(), EXIT));
+ }
+ }
+
+ /**
+ * Validates the cardinality of notification sub-statements as per grammar.
+ *
+ * @param ctx context object of the grammar rule
+ */
+ private static void validateSubStatementsCardinality(GeneratedYangParser.NotificationStatementContext ctx) {
+
+ validateCardinalityMaxOne(ctx.statusStatement(), STATUS_DATA, NOTIFICATION_DATA, ctx.identifier().getText());
+ validateCardinalityMaxOne(ctx.descriptionStatement(), DESCRIPTION_DATA, NOTIFICATION_DATA,
+ ctx.identifier().getText());
+ validateCardinalityMaxOne(ctx.referenceStatement(), REFERENCE_DATA, NOTIFICATION_DATA,
+ ctx.identifier().getText());
+ validateMutuallyExclusiveChilds(ctx.typedefStatement(), TYPEDEF_DATA, ctx.groupingStatement(), GROUPING_DATA,
+ NOTIFICATION_DATA, ctx.identifier().getText());
+ }
+}