[ONOS-3894, 4071] YANG Advanced Construct Union & Grouping
Change-Id: I0f828adb5884c2d7b6e4120f9843c416608ae5e7
diff --git a/utils/yangutils/src/main/java/org/onosproject/yangutils/parser/impl/listeners/UnionListener.java b/utils/yangutils/src/main/java/org/onosproject/yangutils/parser/impl/listeners/UnionListener.java
new file mode 100644
index 0000000..a983f79
--- /dev/null
+++ b/utils/yangutils/src/main/java/org/onosproject/yangutils/parser/impl/listeners/UnionListener.java
@@ -0,0 +1,154 @@
+/*
+ * 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;
+
+/*
+ * Reference: RFC6020 and YANG ANTLR Grammar
+ *
+ * ABNF grammar as per RFC6020
+ * type-body-stmts = numerical-restrictions /
+ * decimal64-specification /
+ * string-restrictions /
+ * enum-specification /
+ * leafref-specification /
+ * identityref-specification /
+ * instance-identifier-specification /
+ * bits-specification /
+ * union-specification
+ *
+ * union-specification = 1*(type-stmt stmtsep)
+ *
+ * ANTLR grammar rule
+ * typeBodyStatements : numericalRestrictions | stringRestrictions | enumSpecification
+ * | leafrefSpecification | identityrefSpecification | instanceIdentifierSpecification
+ * | bitsSpecification | unionSpecification;
+ *
+ * unionSpecification : typeStatement+;
+ */
+
+import org.onosproject.yangutils.datamodel.YangLeaf;
+import org.onosproject.yangutils.datamodel.YangLeafList;
+import org.onosproject.yangutils.datamodel.YangType;
+import org.onosproject.yangutils.datamodel.YangUnion;
+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.parser.impl.parserutils.ListenerErrorLocation.ENTRY;
+import static org.onosproject.yangutils.parser.impl.parserutils.ListenerErrorLocation.EXIT;
+import static org.onosproject.yangutils.parser.impl.parserutils.ListenerErrorMessageConstruction.constructListenerErrorMessage;
+import static org.onosproject.yangutils.parser.impl.parserutils.ListenerErrorType.INVALID_HOLDER;
+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.ListenerValidation.checkStackIsNotEmpty;
+import static org.onosproject.yangutils.utils.YangConstructType.TYPE_DATA;
+import static org.onosproject.yangutils.utils.YangConstructType.UNION_DATA;
+
+/**
+ * Implements listener based call back function corresponding to the "union" rule
+ * defined in ANTLR grammar file for corresponding ABNF rule in RFC 6020.
+ */
+public final class UnionListener {
+ /**
+ * Creates a new union listener.
+ */
+ private UnionListener() {
+ }
+
+ /**
+ * It is called when parser enters grammar rule (union), 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 processUnionEntry(TreeWalkListener listener,
+ GeneratedYangParser.UnionSpecificationContext ctx) {
+
+ // Check for stack to be non empty.
+ checkStackIsNotEmpty(listener, MISSING_HOLDER, UNION_DATA, "", ENTRY);
+
+ if (listener.getParsedDataStack().peek() instanceof YangType) {
+ YangUnion unionNode = new YangUnion();
+ Parsable typeData = listener.getParsedDataStack().pop();
+
+ // Check for stack to be non empty.
+ checkStackIsNotEmpty(listener, MISSING_HOLDER, UNION_DATA, "", ENTRY);
+
+ Parsable tmpData = listener.getParsedDataStack().peek();
+
+ switch (tmpData.getYangConstructType()) {
+ case LEAF_DATA:
+ unionNode.setUnionName(((YangLeaf) tmpData).getLeafName());
+ break;
+ case LEAF_LIST_DATA:
+ unionNode.setUnionName(((YangLeafList) tmpData).getLeafName());
+ break;
+ case UNION_DATA:
+ unionNode.setUnionName(((YangUnion) tmpData).getUnionName());
+ break;
+ // TODO typedef, deviate.
+ default:
+ throw new ParserException(constructListenerErrorMessage(INVALID_HOLDER, TYPE_DATA,
+ ((YangType<?>) typeData).getDataTypeName(), ENTRY));
+ }
+ listener.getParsedDataStack().push(typeData);
+ listener.getParsedDataStack().push(unionNode);
+ } else {
+ throw new ParserException(constructListenerErrorMessage(INVALID_HOLDER, UNION_DATA, "", ENTRY));
+ }
+ }
+
+ /**
+ * It is called when parser exits from grammar rule (union), it perform
+ * validations and update the data model tree.
+ *
+ * @param listener Listener's object
+ * @param ctx context object of the grammar rule
+ */
+ public static void processUnionExit(TreeWalkListener listener,
+ GeneratedYangParser.UnionSpecificationContext ctx) {
+
+ // Check for stack to be non empty.
+ checkStackIsNotEmpty(listener, MISSING_HOLDER, UNION_DATA, "", EXIT);
+
+ Parsable tmpUnionNode = listener.getParsedDataStack().peek();
+ if (tmpUnionNode instanceof YangUnion) {
+ YangUnion unionNode = (YangUnion) tmpUnionNode;
+ listener.getParsedDataStack().pop();
+
+ // Check for stack to be non empty.
+ checkStackIsNotEmpty(listener, MISSING_HOLDER, UNION_DATA, "", EXIT);
+
+ Parsable tmpNode = listener.getParsedDataStack().peek();
+ switch (tmpNode.getYangConstructType()) {
+ case TYPE_DATA: {
+ YangType<YangUnion> typeNode = (YangType<YangUnion>) tmpNode;
+ typeNode.setDataTypeExtendedInfo(unionNode);
+ break;
+ }
+ default:
+ throw new ParserException(
+ constructListenerErrorMessage(INVALID_HOLDER, UNION_DATA, "", EXIT));
+ }
+ } else {
+ throw new ParserException(
+ constructListenerErrorMessage(MISSING_CURRENT_HOLDER, UNION_DATA, "", EXIT));
+ }
+ }
+}
\ No newline at end of file