[ONOS-4744] Leafref implementation and UT
Change-Id: I151797185e0bb1695c0640b667ae76ef87c4d4b0
diff --git a/utils/yangutils/plugin/src/main/java/org/onosproject/yangutils/parser/impl/listeners/LeafrefListener.java b/utils/yangutils/plugin/src/main/java/org/onosproject/yangutils/parser/impl/listeners/LeafrefListener.java
new file mode 100644
index 0000000..6ada8c5
--- /dev/null
+++ b/utils/yangutils/plugin/src/main/java/org/onosproject/yangutils/parser/impl/listeners/LeafrefListener.java
@@ -0,0 +1,212 @@
+/*
+ * Copyright 2016-present 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.YangLeaf;
+import org.onosproject.yangutils.datamodel.YangLeafList;
+import org.onosproject.yangutils.datamodel.YangLeafRef;
+import org.onosproject.yangutils.datamodel.YangNode;
+import org.onosproject.yangutils.datamodel.YangType;
+import org.onosproject.yangutils.datamodel.exceptions.DataModelException;
+import org.onosproject.yangutils.datamodel.utils.Parsable;
+import org.onosproject.yangutils.linker.impl.YangResolutionInfoImpl;
+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.DataModelUtils.addResolutionInfo;
+import static org.onosproject.yangutils.datamodel.utils.ResolvableStatus.UNRESOLVED;
+import static org.onosproject.yangutils.datamodel.utils.YangConstructType.LEAFREF_DATA;
+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.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.ListenerErrorType.UNHANDLED_PARSED_DATA;
+import static org.onosproject.yangutils.parser.impl.parserutils.ListenerValidation.checkStackIsNotEmpty;
+
+/*
+ * 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
+ *
+ * leafref-specification =
+ * ;; these stmts can appear in any order
+ * path-stmt stmtsep
+ * [require-instance-stmt stmtsep]
+ *
+ * ANTLR grammar rule
+ *
+ * typeBodyStatements : numericalRestrictions | stringRestrictions | enumSpecification
+ * | leafrefSpecification | identityrefSpecification | instanceIdentifierSpecification
+ * | bitsSpecification | unionSpecification;
+ *
+ * leafrefSpecification : (pathStatement (requireInstanceStatement)?) | ((requireInstanceStatement)? pathStatement);
+ */
+
+/**
+ * Represents listener based call back function corresponding to the
+ * "leafref" rule defined in ANTLR grammar file for corresponding ABNF rule
+ * in RFC 6020.
+ */
+public final class LeafrefListener {
+
+ /**
+ * Creates a new leafref listener.
+ */
+ private LeafrefListener() {
+ }
+
+ /**
+ * It is called when parser receives an input matching the grammar rule
+ * (leafref), perform validations and updates the data model tree.
+ *
+ * @param listener listener's object
+ * @param ctx context object of the grammar rule
+ */
+ public static void processLeafrefEntry(TreeWalkListener listener,
+ GeneratedYangParser.LeafrefSpecificationContext ctx) {
+
+ // Check for stack to be non empty.
+ checkStackIsNotEmpty(listener, MISSING_HOLDER, LEAFREF_DATA, "", ENTRY);
+
+ int errorLine = ctx.getStart().getLine();
+ int errorPosition = ctx.getStart().getCharPositionInLine();
+
+ YangLeafRef<?> leafRef = new YangLeafRef<>();
+
+ Parsable typeData = listener.getParsedDataStack().pop();
+
+ if (!(typeData instanceof YangType)) {
+ throw new ParserException(constructListenerErrorMessage(INVALID_HOLDER, LEAFREF_DATA,
+ "", ENTRY));
+ }
+
+ YangType type = (YangType) typeData;
+ type.setDataTypeExtendedInfo(leafRef);
+
+ // Setting by default the value of require-instance as true.
+ leafRef.setRequireInstance(true);
+ Parsable tmpData = listener.getParsedDataStack().peek();
+
+ switch (tmpData.getYangConstructType()) {
+
+ case LEAF_DATA:
+
+ // Parent YANG node of leaf to be added in resolution information.
+ YangLeaf leaf = (YangLeaf) listener.getParsedDataStack().pop();
+ Parsable parentNodeOfLeaf = listener.getParsedDataStack().peek();
+ listener.getParsedDataStack().push(leaf);
+
+ // Verify parent node of leaf.
+ if (!(parentNodeOfLeaf instanceof YangNode)) {
+ throw new ParserException(constructListenerErrorMessage(INVALID_HOLDER, LEAFREF_DATA,
+ "", ENTRY));
+ }
+
+ leafRef.setResolvableStatus(UNRESOLVED);
+
+ // Add resolution information to the list.
+ YangResolutionInfoImpl resolutionInfo = new YangResolutionInfoImpl<YangLeafRef>(leafRef,
+ (YangNode) parentNodeOfLeaf, errorLine, errorPosition);
+ addToResolutionList(resolutionInfo);
+ break;
+
+ case LEAF_LIST_DATA:
+
+ // Parent YANG node of leaf-list to be added in resolution information.
+ YangLeafList leafList = (YangLeafList) listener.getParsedDataStack().pop();
+ Parsable parentNodeOfLeafList = listener.getParsedDataStack().peek();
+ listener.getParsedDataStack().push(leafList);
+
+ // Verify parent node of leaf-list.
+ if (!(parentNodeOfLeafList instanceof YangNode)) {
+ throw new ParserException(constructListenerErrorMessage(INVALID_HOLDER, LEAFREF_DATA,
+ "", ENTRY));
+ }
+
+ leafRef.setResolvableStatus(UNRESOLVED);
+
+ // Add resolution information to the list.
+ YangResolutionInfoImpl resolutionInfoImpl = new YangResolutionInfoImpl<YangLeafRef>(leafRef,
+ (YangNode) parentNodeOfLeafList, errorLine, errorPosition);
+ addToResolutionList(resolutionInfoImpl);
+ break;
+
+ case TYPEDEF_DATA:
+ /*
+ * Do not add the leaf ref to resolution list. It needs to be
+ * added to resolution list, when leaf/leaf list references to
+ * this typedef. At this time that leaf/leaf-list becomes the
+ * parent for the leafref.
+ */
+ break;
+
+ default:
+ throw new ParserException(constructListenerErrorMessage(INVALID_HOLDER, LEAFREF_DATA,
+ "", ENTRY));
+ }
+ listener.getParsedDataStack().push(typeData);
+ listener.getParsedDataStack().push(leafRef);
+ }
+
+ /**
+ * It is called when parser exits from grammar rule (leafref), it performs
+ * validation and updates the data model tree.
+ *
+ * @param listener listener's object
+ * @param ctx context object of the grammar rule
+ */
+ public static void processLeafrefExit(TreeWalkListener listener,
+ GeneratedYangParser.LeafrefSpecificationContext ctx) {
+
+ // Check for stack to be non empty.
+ checkStackIsNotEmpty(listener, MISSING_CURRENT_HOLDER, LEAFREF_DATA, "", EXIT);
+
+ Parsable parsableType = listener.getParsedDataStack().pop();
+ if (!(parsableType instanceof YangLeafRef)) {
+ throw new ParserException(constructListenerErrorMessage(INVALID_HOLDER, LEAFREF_DATA,
+ "", EXIT));
+ }
+ }
+
+ /**
+ * Adds to resolution list.
+ *
+ * @param resolutionInfo resolution information
+ */
+ private static void addToResolutionList(YangResolutionInfoImpl resolutionInfo) {
+
+ try {
+ addResolutionInfo(resolutionInfo);
+ } catch (DataModelException e) {
+ throw new ParserException(constructExtendedListenerErrorMessage(UNHANDLED_PARSED_DATA,
+ LEAFREF_DATA, "", ENTRY, e.getMessage()));
+ }
+ }
+}