[ONOS-3892] implement YANG leaf data model
Change-Id: I996d4d3d60a0ad2142e173c6ba26c9cc355ccc80
diff --git a/utils/yangutils/src/main/java/org/onosproject/yangutils/datamodel/YangImport.java b/utils/yangutils/src/main/java/org/onosproject/yangutils/datamodel/YangImport.java
new file mode 100644
index 0000000..cf18a62
--- /dev/null
+++ b/utils/yangutils/src/main/java/org/onosproject/yangutils/datamodel/YangImport.java
@@ -0,0 +1,176 @@
+/*
+ * 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 "import" statement makes definitions from one module available
+ * inside another module or submodule. The argument is the name of the
+ * module to import, and the statement is followed by a block of
+ * sub statements that holds detailed import information.
+ * When a module is imported, the importing module may:
+ * o use any grouping and typedef defined at the top level in the
+ * imported module or its submodules.
+ *
+ * o use any extension, feature, and identity defined in the imported
+ * module or its submodules.
+ *
+ * o use any node in the imported module's schema tree in "must",
+ * "path", and "when" statements, or as the target node in "augment"
+ * and "deviation" statements.
+ *
+ * The mandatory "prefix" sub statement assigns a prefix for the imported
+ * module that is scoped to the importing module or submodule. Multiple
+ * "import" statements may be specified to import from different
+ * modules.
+ * When the optional "revision-date" sub-statement is present, any
+ * typedef, grouping, extension, feature, and identity referenced by
+ * definitions in the local module are taken from the specified revision
+ * of the imported module. It is an error if the specified revision of
+ * the imported module does not exist. If no "revision-date"
+ * sub-statement is present, it is undefined from which revision of the
+ * module they are taken.
+ *
+ * Multiple revisions of the same module MUST NOT be imported.
+ *
+ * The import's Substatements
+ *
+ * +---------------+---------+-------------+------------------+
+ * | substatement | section | cardinality |data model mapping|
+ * +---------------+---------+-------------+------------------+
+ * | prefix | 7.1.4 | 1 | string |
+ * | revision-date | 7.1.5.1 | 0..1 | string |
+ * +---------------+---------+-------------+------------------+
+ */
+/**
+ * Maintains the information about the imported modules.
+ */
+public class YangImport implements Parsable {
+
+ /**
+ * Name of the module that is being imported.
+ */
+ private String name;
+
+ /**
+ * Prefix used to identify the entities from the imported module.
+ */
+ private String prefixId;
+
+ /**
+ * Reference:RFC 6020.
+ * The import's "revision-date" statement is used to specify the exact
+ * version of the module to import. The "revision-date" statement MUST match
+ * the most recent "revision" statement in the imported module. organization
+ * which defined the YANG module.
+ */
+ private String revision;
+
+ /**
+ * Default constructor.
+ */
+ public YangImport() {
+
+ }
+
+ /**
+ * Get the imported module name.
+ *
+ * @return the module name.
+ */
+ public String getModuleName() {
+ return name;
+ }
+
+ /**
+ * Set module name.
+ *
+ * @param moduleName the module name to set
+ */
+ public void setModuleName(String moduleName) {
+ name = moduleName;
+ }
+
+ /**
+ * Get the prefix used to identify the entities from the imported module.
+ *
+ * @return the prefix used to identify the entities from the imported
+ * module.
+ */
+ public String getPrefixId() {
+ return prefixId;
+ }
+
+ /**
+ * Set prefix identifier.
+ *
+ * @param prefixId set the prefix identifier of the imported module.
+ */
+ public void setPrefixId(String prefixId) {
+ this.prefixId = prefixId;
+ }
+
+ /**
+ * Get the revision of the imported module.
+ *
+ * @return the revision of the imported module.
+ */
+ public String getRevision() {
+ return revision;
+ }
+
+ /**
+ * Set the revision of the imported module.
+ *
+ * @param rev set the revision of the imported module.
+ */
+ public void setRevision(String rev) {
+ revision = rev;
+ }
+
+ /**
+ * Returns the type of the parsed data.
+ *
+ * @return returns IMPORT_DATA
+ */
+ public ParsableDataType getParsableDataType() {
+ return ParsableDataType.IMPORT_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
+
+ }
+}
diff --git a/utils/yangutils/src/main/java/org/onosproject/yangutils/datamodel/YangInclude.java b/utils/yangutils/src/main/java/org/onosproject/yangutils/datamodel/YangInclude.java
new file mode 100644
index 0000000..de7355c
--- /dev/null
+++ b/utils/yangutils/src/main/java/org/onosproject/yangutils/datamodel/YangInclude.java
@@ -0,0 +1,124 @@
+/*
+ * 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 "include" statement is used to make content from a submodule
+ * available to that submodule's parent module, or to another submodule
+ * of that parent module. The argument is an identifier that is the
+ * name of the submodule to include.
+ * The includes's Substatements
+ *
+ * +---------------+---------+-------------+------------------+
+ * | substatement | section | cardinality |data model mapping|
+ * +---------------+---------+-------------+------------------+
+ * | revision-date | 7.1.5.1 | 0..1 | string |
+ * +---------------+---------+-------------+------------------+
+ */
+/**
+ * Maintains the information about the included sub-modules.
+ *
+ */
+public class YangInclude implements Parsable {
+
+ /**
+ * Name of the sub-module that is being included.
+ */
+ private String subModuleName;
+
+ /**
+ * The include's "revision-date" statement is used to specify the exact
+ * version of the submodule to import.
+ */
+ private String revision;
+
+ /**
+ * Default constructor.
+ */
+ public YangInclude() {
+ }
+
+ /**
+ * Get the name of included sub-module.
+ *
+ * @return the sub-module name
+ */
+ public String getSubModuleName() {
+ return subModuleName;
+ }
+
+ /**
+ * Set the name of included sub-modules.
+ *
+ * @param subModuleName the sub-module name to set
+ */
+ public void setSubModuleName(String subModuleName) {
+ this.subModuleName = subModuleName;
+ }
+
+ /**
+ * Get the revision.
+ *
+ * @return the revision
+ */
+ public String getRevision() {
+ return revision;
+ }
+
+ /**
+ * Set the revision.
+ *
+ * @param revision the revision to set
+ */
+ public void setRevision(String revision) {
+ this.revision = revision;
+ }
+
+ /**
+ * Returns the type of parsed data.
+ *
+ * @return returns INCLUDE_DATA
+ */
+ public ParsableDataType getParsableDataType() {
+ return ParsableDataType.INCLUDE_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
+
+ }
+
+}
diff --git a/utils/yangutils/src/main/java/org/onosproject/yangutils/datamodel/YangLeaf.java b/utils/yangutils/src/main/java/org/onosproject/yangutils/datamodel/YangLeaf.java
new file mode 100644
index 0000000..d2837da
--- /dev/null
+++ b/utils/yangutils/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
+
+ }
+}
diff --git a/utils/yangutils/src/main/java/org/onosproject/yangutils/datamodel/YangLeafList.java b/utils/yangutils/src/main/java/org/onosproject/yangutils/datamodel/YangLeafList.java
new file mode 100644
index 0000000..d005458
--- /dev/null
+++ b/utils/yangutils/src/main/java/org/onosproject/yangutils/datamodel/YangLeafList.java
@@ -0,0 +1,320 @@
+/*
+ * 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.
+ * Where the "leaf" statement is used to define a simple scalar variable
+ * of a particular type, the "leaf-list" statement is used to define an
+ * array of a particular type. The "leaf-list" statement takes one
+ * argument, which is an identifier, followed by a block of
+ * sub-statements that holds detailed leaf-list information.
+ *
+ * The values in a leaf-list MUST be unique.
+ *
+ * The leaf-list's sub-statements
+ *
+ * +--------------+---------+-------------+------------------+
+ * | substatement | section | cardinality |data model mapping|
+ * +--------------+---------+-------------+------------------+
+ * | config | 7.19.1 | 0..1 | -boolean |
+ * | description | 7.19.3 | 0..1 | -string |
+ * | if-feature | 7.18.2 | 0..n | -TODO |
+ * | max-elements | 7.7.4 | 0..1 | -int |
+ * | min-elements | 7.7.3 | 0..1 | -int |
+ * | must | 7.5.3 | 0..n | -TODO |
+ * | ordered-by | 7.7.5 | 0..1 | -TODO |
+ * | reference | 7.19.4 | 0..1 | -string |
+ * | status | 7.19.2 | 0..1 | -YangStatus |
+ * | type | 7.4 | 1 | -YangType |
+ * | units | 7.3.3 | 0..1 | -string |
+ * | when | 7.19.5 | 0..1 | -TODO |
+ * +--------------+---------+-------------+------------------+
+ */
+/**
+ * Leaf-list data represented in YANG.
+ *
+ * @param <T> YANG data type
+ */
+public class YangLeafList<T> implements YangCommonInfo, Parsable {
+
+ /**
+ * Name of leaf-list.
+ */
+ private String name;
+
+ /**
+ * If the leaf-list is a config parameter.
+ */
+ private boolean isConfig;
+
+ /**
+ * Description of leaf-list.
+ */
+ private String description;
+
+ /**
+ * Reference:RFC 6020.
+ * The "max-elements" statement, which is optional, takes as an argument a
+ * positive integer or the string "unbounded", which puts a constraint on
+ * valid list entries. A valid leaf-list or list always has at most
+ * max-elements entries.
+ *
+ * If no "max-elements" statement is present, it defaults to "unbounded".
+ */
+ private int maxElelements;
+
+ /**
+ * Reference:RFC 6020.
+ * The "min-elements" statement, which is optional, takes as an argument a
+ * non-negative integer that puts a constraint on valid list entries. A
+ * valid leaf-list or list MUST have at least min-elements entries.
+ *
+ * If no "min-elements" statement is present, it defaults to zero.
+ *
+ * The behavior of the constraint depends on the type of the leaf-list's or
+ * list's closest ancestor node in the schema tree that is not a non-
+ * presence container:
+ *
+ * o If this ancestor is a case node, the constraint is enforced if any
+ * other node from the case exists.
+ *
+ * o Otherwise, it is enforced if the ancestor node exists.
+ */
+ private int minElements;
+
+ /**
+ * The textual reference to this leaf-list.
+ */
+ private String reference;
+
+ /**
+ * Status of the leaf-list in the YANG definition.
+ */
+ private YangStatusType status;
+
+ /**
+ * Textual units.
+ */
+ private String units;
+
+ /**
+ * Data type of leaf-list.
+ */
+ private YangType<T> dataType;
+
+ /**
+ * Default Constructor to create a YANG leaf-list.
+ */
+ public YangLeafList() {
+ }
+
+ /**
+ * Get the leaf-list name.
+ *
+ * @return the leaf-list name.
+ */
+ public String getLeafName() {
+ return name;
+ }
+
+ /**
+ * Set the leaf-list name.
+ *
+ * @param leafListName the leaf-list name to set.
+ */
+ public void setLeafName(String leafListName) {
+ this.name = leafListName;
+ }
+
+ /**
+ * Get the config flag.
+ *
+ * @return the config flag.
+ */
+ public boolean isConfig() {
+ return isConfig;
+ }
+
+ /**
+ * Set the config flag.
+ *
+ * @param isCfg the config flag.
+ */
+ 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 the max elements no.
+ *
+ * @return the max elements no.
+ */
+ public int getMaxElelements() {
+ return maxElelements;
+ }
+
+ /**
+ * Set the max elements no.
+ *
+ * @param maxElelements max elements no.
+ */
+ public void setMaxElelements(int maxElelements) {
+ this.maxElelements = maxElelements;
+ }
+
+ /**
+ * Get the min elements no.
+ *
+ * @return the min elements no.
+ */
+ public int getMinElements() {
+ return minElements;
+ }
+
+ /**
+ * Set the min elements no.
+ *
+ * @param minElements the min elements no.
+ */
+ public void setMinElements(int minElements) {
+ this.minElements = minElements;
+ }
+
+ /**
+ * 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_LIST_DATA.
+ */
+ public ParsableDataType getParsableDataType() {
+ return ParsableDataType.LEAF_LIST_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
+
+ }
+}
diff --git a/utils/yangutils/src/main/java/org/onosproject/yangutils/datamodel/YangLeavesHolder.java b/utils/yangutils/src/main/java/org/onosproject/yangutils/datamodel/YangLeavesHolder.java
new file mode 100644
index 0000000..917d591
--- /dev/null
+++ b/utils/yangutils/src/main/java/org/onosproject/yangutils/datamodel/YangLeavesHolder.java
@@ -0,0 +1,54 @@
+/*Copyright 2016.year 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 java.util.List;
+
+/**
+ * Abstraction of atomic configurable/status entity. It is used to abstract the
+ * data holders of leaf or leaf list. Used in leaves parsing or attribute code
+ * generation.
+ */
+public interface YangLeavesHolder {
+
+ /**
+ * Get the list of leaves from data holder like container / list.
+ *
+ * @return the list of leaves.
+ */
+ @SuppressWarnings("rawtypes")
+ public List<YangLeaf> getListOfLeaf();
+
+ /**
+ * Add a leaf in data holder like container / list.
+ *
+ * @param leaf the leaf to be added.
+ */
+ void addLeaf(YangLeaf<?> leaf);
+
+ /**
+ * Get the list of leaf-list from data holder like container / list.
+ *
+ * @return the list of leaf-list.
+ */
+ @SuppressWarnings("rawtypes")
+ List<YangLeafList> getListOfLeafList();
+
+ /**
+ * Add a leaf-list in data holder like container / list.
+ *
+ * @param leafList the leaf-list to be added.
+ */
+ void addLeafList(YangLeafList<?> leafList);
+}