[ONOS-3894, 4071] YANG Advanced Construct Union & Grouping
Change-Id: I0f828adb5884c2d7b6e4120f9843c416608ae5e7
diff --git a/src/main/java/org/onosproject/yangutils/parser/impl/listeners/UsesListener.java b/src/main/java/org/onosproject/yangutils/parser/impl/listeners/UsesListener.java
new file mode 100644
index 0000000..59e744e
--- /dev/null
+++ b/src/main/java/org/onosproject/yangutils/parser/impl/listeners/UsesListener.java
@@ -0,0 +1,164 @@
+package org.onosproject.yangutils.parser.impl.listeners;
+
+import org.onosproject.yangutils.datamodel.YangAugment;
+import org.onosproject.yangutils.datamodel.YangCase;
+import org.onosproject.yangutils.datamodel.YangContainer;
+import org.onosproject.yangutils.datamodel.YangGrouping;
+import org.onosproject.yangutils.datamodel.YangInput;
+import org.onosproject.yangutils.datamodel.YangList;
+import org.onosproject.yangutils.datamodel.YangModule;
+import org.onosproject.yangutils.datamodel.YangNode;
+import org.onosproject.yangutils.datamodel.YangNotification;
+import org.onosproject.yangutils.datamodel.YangOutput;
+import org.onosproject.yangutils.datamodel.YangSubModule;
+import org.onosproject.yangutils.datamodel.YangUses;
+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.getYangUsesNode;
+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;
+import static org.onosproject.yangutils.parser.impl.parserutils.ListenerValidation.validateCardinalityMaxOne;
+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.STATUS_DATA;
+import static org.onosproject.yangutils.utils.YangConstructType.USES_DATA;
+import static org.onosproject.yangutils.utils.YangConstructType.WHEN_DATA;
+
+/*
+ * Reference: RFC6020 and YANG ANTLR Grammar
+ *
+ * ABNF grammar as per RFC6020
+ * data-def-stmt = container-stmt /
+ * leaf-stmt /
+ * leaf-list-stmt /
+ * list-stmt /
+ * choice-stmt /
+ * anyxml-stmt /
+ * uses-stmt
+ *
+ * uses-stmt = uses-keyword sep identifier-ref-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]
+ * *(refine-stmt stmtsep)
+ * *(uses-augment-stmt stmtsep)
+ * "}")
+ *
+ * ANTLR grammar rule
+ * dataDefStatement : containerStatement
+ * | leafStatement
+ * | leafListStatement
+ * | listStatement
+ * | choiceStatement
+ * | usesStatement;
+ *
+ * usesStatement : USES_KEYWORD string (STMTEND | LEFT_CURLY_BRACE (whenStatement | ifFeatureStatement
+ * | statusStatement | descriptionStatement | referenceStatement | refineStatement
+ * | usesAugmentStatement)* RIGHT_CURLY_BRACE);
+ */
+
+/**
+ * Implements listener based call back function corresponding to the "uses"
+ * rule defined in ANTLR grammar file for corresponding ABNF rule in RFC 6020.
+ */
+public final class UsesListener {
+
+ /**
+ * Creates a new uses listener.
+ */
+ private UsesListener() {
+ }
+
+ /**
+ * It is called when parser enters grammar rule (uses), 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 processUsesEntry(TreeWalkListener listener, GeneratedYangParser.UsesStatementContext ctx) {
+
+ // Check for stack to be non empty.
+ checkStackIsNotEmpty(listener, MISSING_HOLDER, USES_DATA, ctx.string().getText(), ENTRY);
+
+ // Validate sub statement cardinality.
+ validateSubStatementsCardinality(ctx);
+
+ Parsable curData = listener.getParsedDataStack().peek();
+
+ if (curData instanceof YangModule || curData instanceof YangSubModule
+ || curData instanceof YangContainer || curData instanceof YangList
+ || curData instanceof YangUses || curData instanceof YangAugment
+ || curData instanceof YangCase || curData instanceof YangGrouping
+ || curData instanceof YangInput || curData instanceof YangOutput
+ || curData instanceof YangNotification) {
+
+ YangUses usesNode = getYangUsesNode(JAVA_GENERATION);
+ usesNode.setName(ctx.string().getText());
+
+ YangNode curNode = (YangNode) curData;
+
+ try {
+ curNode.addChild(usesNode);
+ } catch (DataModelException e) {
+ throw new ParserException(constructExtendedListenerErrorMessage(UNHANDLED_PARSED_DATA,
+ USES_DATA, ctx.string().getText(), ENTRY, e.getMessage()));
+ }
+ listener.getParsedDataStack().push(usesNode);
+ } else {
+ throw new ParserException(constructListenerErrorMessage(INVALID_HOLDER,
+ USES_DATA, ctx.string().getText(), ENTRY));
+ }
+ }
+
+ /**
+ * It is called when parser exits from grammar rule (uses), 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 processUsesExit(TreeWalkListener listener,
+ GeneratedYangParser.UsesStatementContext ctx) {
+
+ // Check for stack to be non empty.
+ checkStackIsNotEmpty(listener, MISSING_HOLDER, USES_DATA, ctx.string().getText(), EXIT);
+
+ if (listener.getParsedDataStack().peek() instanceof YangUses) {
+ listener.getParsedDataStack().pop();
+ } else {
+ throw new ParserException(constructListenerErrorMessage(MISSING_CURRENT_HOLDER, USES_DATA,
+ ctx.string().getText(), EXIT));
+ }
+ }
+
+ // TODO linker to handle collision scenarios like leaf obtained by uses, conflicts with some existing leaf.
+
+ /**
+ * Validates the cardinality of case sub-statements as per grammar.
+ *
+ * @param ctx context object of the grammar rule
+ */
+ private static void validateSubStatementsCardinality(GeneratedYangParser.UsesStatementContext ctx) {
+ validateCardinalityMaxOne(ctx.whenStatement(), WHEN_DATA, USES_DATA, ctx.string().getText());
+ validateCardinalityMaxOne(ctx.statusStatement(), STATUS_DATA, USES_DATA, ctx.string().getText());
+ validateCardinalityMaxOne(ctx.descriptionStatement(), DESCRIPTION_DATA, USES_DATA, ctx.string().getText());
+ validateCardinalityMaxOne(ctx.referenceStatement(), REFERENCE_DATA, USES_DATA, ctx.string().getText()); }
+}