YANG augment listener
Change-Id: I11ece665a7627d784f82247d5a33e3453632d0f9
diff --git a/utils/yangutils/src/main/java/org/onosproject/yangutils/parser/impl/listeners/AugmentListener.java b/utils/yangutils/src/main/java/org/onosproject/yangutils/parser/impl/listeners/AugmentListener.java
new file mode 100644
index 0000000..d332ab9
--- /dev/null
+++ b/utils/yangutils/src/main/java/org/onosproject/yangutils/parser/impl/listeners/AugmentListener.java
@@ -0,0 +1,166 @@
+/*
+ * 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 java.util.List;
+import org.onosproject.yangutils.datamodel.YangAugment;
+import org.onosproject.yangutils.datamodel.YangNode;
+import org.onosproject.yangutils.datamodel.YangModule;
+import org.onosproject.yangutils.datamodel.YangSubModule;
+import org.onosproject.yangutils.datamodel.YangNodeIdentifier;
+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.getYangAugmentNode;
+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.MISSING_CURRENT_HOLDER;
+import static org.onosproject.yangutils.parser.impl.parserutils.ListenerErrorType.MISSING_HOLDER;
+import static org.onosproject.yangutils.parser.impl.parserutils.ListenerErrorType.UNHANDLED_PARSED_DATA;
+import static org.onosproject.yangutils.parser.impl.parserutils.ListenerErrorType.INVALID_HOLDER;
+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.parser.impl.parserutils.ListenerUtil.getValidAbsoluteSchemaNodeId;
+import static org.onosproject.yangutils.utils.YangConstructType.AUGMENT_DATA;
+import static org.onosproject.yangutils.utils.YangConstructType.DATA_DEF_DATA;
+import static org.onosproject.yangutils.utils.YangConstructType.STATUS_DATA;
+import static org.onosproject.yangutils.utils.YangConstructType.REFERENCE_DATA;
+import static org.onosproject.yangutils.utils.YangConstructType.DESCRIPTION_DATA;
+import static org.onosproject.yangutils.utils.YangConstructType.WHEN_DATA;
+import static org.onosproject.yangutils.utils.YangConstructType.CASE_DATA;
+
+/*
+ * Reference: RFC6020 and YANG ANTLR Grammar
+ *
+ * ABNF grammar as per RFC6020
+ * augment-stmt = augment-keyword sep augment-arg-str optsep
+ * "{" stmtsep
+ * ;; these stmts can appear in any order
+ * [when-stmt stmtsep]
+ * *(if-feature-stmt stmtsep)
+ * [status-stmt stmtsep]
+ * [description-stmt stmtsep]
+ * [reference-stmt stmtsep]
+ * 1*((data-def-stmt stmtsep) /
+ * (case-stmt stmtsep))
+ * "}"
+ *
+ * ANTLR grammar rule
+ * augmentStatement : AUGMENT_KEYWORD augment LEFT_CURLY_BRACE (whenStatement | ifFeatureStatement | statusStatement
+ * | descriptionStatement | referenceStatement | dataDefStatement | caseStatement)* RIGHT_CURLY_BRACE;
+ */
+
+/**
+ * Implements listener based call back function corresponding to the "augment"
+ * rule defined in ANTLR grammar file for corresponding ABNF rule in RFC 6020.
+ */
+public final class AugmentListener {
+
+ /**
+ * Creates a new augment listener.
+ */
+ private AugmentListener() {
+ }
+
+ /**
+ * It is called when parser receives an input matching the grammar rule
+ * (augment), performs validation and updates the data model tree.
+ *
+ * @param listener listener's object
+ * @param ctx context object of the grammar rule
+ */
+ public static void processAugmentEntry(TreeWalkListener listener,
+ GeneratedYangParser.AugmentStatementContext ctx) {
+
+ // Check for stack to be non empty.
+ checkStackIsNotEmpty(listener, MISSING_HOLDER, AUGMENT_DATA, ctx.augment().getText(), ENTRY);
+
+ // Validate augment argument string
+ List<YangNodeIdentifier> targetNodes = getValidAbsoluteSchemaNodeId(ctx.augment().getText(),
+ AUGMENT_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, "", AUGMENT_DATA);
+
+ Parsable curData = listener.getParsedDataStack().peek();
+ if (curData instanceof YangModule || curData instanceof YangSubModule) {
+
+ YangNode curNode = (YangNode) curData;
+ YangAugment yangAugment = getYangAugmentNode(JAVA_GENERATION);
+ yangAugment.setTargetNode(targetNodes);
+ try {
+ curNode.addChild(yangAugment);
+ } catch (DataModelException e) {
+ throw new ParserException(constructExtendedListenerErrorMessage(UNHANDLED_PARSED_DATA,
+ AUGMENT_DATA, ctx.augment().getText(), ENTRY, e.getMessage()));
+ }
+ listener.getParsedDataStack().push(yangAugment);
+ } else {
+ throw new ParserException(constructListenerErrorMessage(INVALID_HOLDER, AUGMENT_DATA,
+ ctx.augment().getText(), ENTRY));
+ }
+
+ }
+
+ /**
+ * It is called when parser exits from grammar rule (augment), 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 processAugmentExit(TreeWalkListener listener,
+ GeneratedYangParser.AugmentStatementContext ctx) {
+
+ //Check for stack to be non empty.
+ checkStackIsNotEmpty(listener, MISSING_HOLDER, AUGMENT_DATA, ctx.augment().getText(), EXIT);
+
+ if (!(listener.getParsedDataStack().peek() instanceof YangAugment)) {
+ throw new ParserException(constructListenerErrorMessage(MISSING_CURRENT_HOLDER, AUGMENT_DATA,
+ ctx.augment().getText(), EXIT));
+ }
+ listener.getParsedDataStack().pop();
+ }
+
+ /**
+ * Validates the cardinality of augment sub-statements as per grammar.
+ *
+ * @param ctx context object of the grammar rule
+ */
+ private static void validateSubStatementsCardinality(GeneratedYangParser.AugmentStatementContext ctx) {
+
+ validateCardinalityMaxOne(ctx.statusStatement(), STATUS_DATA, AUGMENT_DATA, ctx.augment().getText());
+ validateCardinalityMaxOne(ctx.descriptionStatement(), DESCRIPTION_DATA, AUGMENT_DATA, ctx.augment().getText());
+ validateCardinalityMaxOne(ctx.referenceStatement(), REFERENCE_DATA, AUGMENT_DATA, ctx.augment().getText());
+ validateCardinalityMaxOne(ctx.whenStatement(), WHEN_DATA, AUGMENT_DATA, ctx.augment().getText());
+ validateMutuallyExclusiveChilds(ctx.dataDefStatement(), DATA_DEF_DATA, ctx.caseStatement(),
+ CASE_DATA, AUGMENT_DATA, ctx.augment().getText());
+ }
+}