[ONOS-3878] YANG Listeners methods for Module and SubModule
Change-Id: Ied2fcf631d302b26ef84af8e98895d8ccb6d6269
diff --git a/src/main/java/org/onosproject/yangutils/parser/impl/listeners/NamespaceListener.java b/src/main/java/org/onosproject/yangutils/parser/impl/listeners/NamespaceListener.java
new file mode 100644
index 0000000..6f694e1
--- /dev/null
+++ b/src/main/java/org/onosproject/yangutils/parser/impl/listeners/NamespaceListener.java
@@ -0,0 +1,68 @@
+/*
+ * 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.parser.antlrgencode.GeneratedYangParser;
+import org.onosproject.yangutils.parser.impl.TreeWalkListener;
+
+/*
+ * Reference: RFC6020 and YANG ANTLR Grammar
+ *
+ * ABNF grammar as per RFC6020
+ * module-header-stmts = ;; these stmts can appear in any order
+ * [yang-version-stmt stmtsep]
+ * namespace-stmt stmtsep
+ * prefix-stmt stmtsep
+ *
+ * namespace-stmt = namespace-keyword sep uri-str optsep stmtend
+ *
+ * ANTLR grammar rule
+ * module_header_statement : yang_version_stmt? namespace_stmt prefix_stmt
+ * | yang_version_stmt? prefix_stmt namespace_stmt
+ * | namespace_stmt yang_version_stmt? prefix_stmt
+ * | namespace_stmt prefix_stmt yang_version_stmt?
+ * | prefix_stmt namespace_stmt yang_version_stmt?
+ * | prefix_stmt yang_version_stmt? namespace_stmt
+ * ;
+ * namespace_stmt : NAMESPACE_KEYWORD string STMTEND;
+ */
+
+/**
+ * Implements listener based call back function corresponding to the "namespace"
+ * rule defined in ANTLR grammar file for corresponding ABNF rule in RFC 6020.
+ */
+public final class NamespaceListener {
+
+ /**
+ * Creates a new namespace listener.
+ */
+ private NamespaceListener() {
+ }
+
+ /**
+ * It is called when parser receives an input matching the grammar
+ * rule (namespace), perform validations and update the data model
+ * tree.
+ *
+ * @param listener Listener's object.
+ * @param ctx context object of the grammar rule.
+ */
+ public static void processNamespaceEntry(TreeWalkListener listener,
+ GeneratedYangParser.NamespaceStatementContext ctx) {
+ // TODO method implementation
+ }
+}