[ONOS-3892] implement YANG leaf data model
Change-Id: I996d4d3d60a0ad2142e173c6ba26c9cc355ccc80
diff --git a/src/main/java/org/onosproject/yangutils/datamodel/YangLeaf.java b/src/main/java/org/onosproject/yangutils/datamodel/YangLeaf.java
new file mode 100644
index 0000000..d2837da
--- /dev/null
+++ b/src/main/java/org/onosproject/yangutils/datamodel/YangLeaf.java
@@ -0,0 +1,281 @@
+/*
+ * 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.datamodel;
+
+import org.onosproject.yangutils.datamodel.exceptions.DataModelException;
+import org.onosproject.yangutils.parser.Parsable;
+import org.onosproject.yangutils.parser.ParsableDataType;
+
+/*
+ * Reference:RFC 6020.
+ * The "leaf" statement is used to define a leaf node in the schema
+ * tree. It takes one argument, which is an identifier, followed by a
+ * block of sub-statements that holds detailed leaf information.
+ *
+ * A leaf node has a value, but no child nodes in the data tree.
+ * Conceptually, the value in the data tree is always in the canonical
+ * form.
+ *
+ * A leaf node exists in zero or one instances in the data tree.
+ *
+ * The "leaf" statement is used to define a scalar variable of a
+ * particular built-in or derived type.
+ *
+ * The leaf's sub-statements
+ *
+ * +--------------+---------+-------------+------------------+
+ * | substatement | section | cardinality |data model mapping|
+ * +--------------+---------+-------------+------------------+
+ * | config | 7.19.1 | 0..1 | - boolean |
+ * | default | 7.6.4 | 0..1 | - TODO |
+ * | description | 7.19.3 | 0..1 | - string |
+ * | if-feature | 7.18.2 | 0..n | - TODO |
+ * | mandatory | 7.6.5 | 0..1 | - boolean |
+ * | must | 7.5.3 | 0..n | - TODO |
+ * | reference | 7.19.4 | 0..1 | - string |
+ * | status | 7.19.2 | 0..1 | - YangStatus |
+ * | type | 7.6.3 | 1 | - YangType |
+ * | units | 7.3.3 | 0..1 | - String |
+ * | when | 7.19.5 | 0..1 | - TODO |
+ * +--------------+---------+-------------+------------------+
+ */
+/**
+ * Leaf data represented in YANG.
+ *
+ * @param <T> YANG data type
+ */
+public class YangLeaf<T> implements YangCommonInfo, Parsable {
+
+ /**
+ * Name of leaf.
+ */
+ private String name;
+
+ /**
+ * If the leaf is a config parameter.
+ */
+ private boolean isConfig;
+
+ /**
+ * description of leaf.
+ */
+ private String description;
+
+ /**
+ * If mandatory leaf.
+ */
+ private boolean isMandatory;
+
+ /**
+ * The textual reference to this leaf.
+ */
+ private String reference;
+
+ /**
+ * Status of leaf in YANG definition.
+ */
+ private YangStatusType status;
+
+ /**
+ * Textual units info.
+ */
+ private String units;
+
+ /**
+ * Data type of the leaf.
+ */
+ private YangType<T> dataType;
+
+ /**
+ * Default constructor to create a YANG leaf.
+ */
+ public YangLeaf() {
+ }
+
+ /**
+ * Get the name of leaf.
+ *
+ * @return the leaf name.
+ */
+ public String getLeafName() {
+ return name;
+ }
+
+ /**
+ * Set the name of leaf.
+ *
+ * @param leafName the leaf name to set.
+ */
+ public void setLeafName(String leafName) {
+ this.name = leafName;
+ }
+
+ /**
+ * Get the config flag.
+ *
+ * @return if config flag.
+ */
+ public boolean isConfig() {
+ return isConfig;
+ }
+
+ /**
+ * Set the config flag.
+ *
+ * @param isCfg the flag value to set.
+ */
+ public void setConfig(boolean isCfg) {
+ isConfig = isCfg;
+ }
+
+ /**
+ * Get the description.
+ *
+ * @return the description.
+ */
+ public String getDescription() {
+ return description;
+ }
+
+ /**
+ * Set the description.
+ *
+ * @param description set the description.
+ */
+ public void setDescription(String description) {
+ this.description = description;
+ }
+
+ /**
+ * Get if the leaf is mandatory.
+ *
+ * @return if leaf is mandatory.
+ */
+ public boolean isMandatory() {
+ return isMandatory;
+ }
+
+ /**
+ * Set if the leaf is mandatory.
+ *
+ * @param isReq if the leaf is mandatory
+ */
+ public void setMandatory(boolean isReq) {
+ isMandatory = isReq;
+ }
+
+ /**
+ * Get the textual reference.
+ *
+ * @return the reference.
+ */
+ public String getReference() {
+ return reference;
+ }
+
+ /**
+ * Set the textual reference.
+ *
+ * @param reference the reference to set.
+ */
+ public void setReference(String reference) {
+ this.reference = reference;
+ }
+
+ /**
+ * Get the status.
+ *
+ * @return the status.
+ */
+ public YangStatusType getStatus() {
+ return status;
+ }
+
+ /**
+ * Set the status.
+ *
+ * @param status the status to set.
+ */
+ public void setStatus(YangStatusType status) {
+ this.status = status;
+ }
+
+ /**
+ * Get the units.
+ *
+ * @return the units.
+ */
+ public String getUnits() {
+ return units;
+ }
+
+ /**
+ * Set the units.
+ *
+ * @param units the units to set.
+ */
+ public void setUnits(String units) {
+ this.units = units;
+ }
+
+ /**
+ * Get the data type.
+ *
+ * @return the data type.
+ */
+ public YangType<T> getDataType() {
+ return dataType;
+ }
+
+ /**
+ * Set the data type.
+ *
+ * @param dataType the data type to set.
+ */
+ public void setDataType(YangType<T> dataType) {
+ this.dataType = dataType;
+ }
+
+ /**
+ * Returns the type of the parsed data.
+ *
+ * @return returns LEAF_DATA.
+ */
+ public ParsableDataType getParsableDataType() {
+ return ParsableDataType.LEAF_DATA;
+ }
+
+ /**
+ * Validate the data on entering the corresponding parse tree node.
+ *
+ * @throws DataModelException a violation of data model rules.
+ */
+ public void validateDataOnEntry() throws DataModelException {
+ // TODO auto-generated method stub, to be implemented by parser
+
+ }
+
+ /**
+ * Validate the data on exiting the corresponding parse tree node.
+ *
+ * @throws DataModelException a violation of data model rules.
+ */
+ public void validateDataOnExit() throws DataModelException {
+ // TODO auto-generated method stub, to be implemented by parser
+
+ }
+}