Table of Contents

Overview

...

An XML-based equivalent version of YANG is called YIN
YANG uses a tree to define the hierarchy of data wherein each ‘node’ has a value or/and a set of child nodes
- 4 types of nodes
  - container nodes
  - list nodes
  - leaf nodes
  - leaf-list nodes

Basic YANG statements

Sample YANG

(stores.yang)

Statements and Description

Code Block

language	text
theme	Confluence
linenumbers	true

module stores {
    yang-version 1.1;
    namespace "org:onap:ccsdk:sample";

    prefix book-store;

    revision "2020-09-15" {
        description
        "Sample Model";
    }

    typedef year {
        type uint16 {
            range "1000..9999";
        }
    }

    container bookstore { 

        leaf bookstore-name {
            type string;
        }
    list categories {

        key "code";

        leaf code {	
            type string;
        }

        leaf name {
            type string;
        }

        list books {
            key title;

            leaf title {
                type string;
            }
            leaf-list authors {
                type string; 
            }
        }
    }
    }
}

module Statement

see example from Line 1

YANG language defines models with modules and submodules
Takes one argument (module name) which is the identifier
Groups all statements that belong to the module
This module example contains the following statements for header information:

see examples from Lines 2-16

- - yang-version statement
  - namespace statement prefix statement
  - revision statements

typedef Statement

see example from Line 12

a statement that allows a new type to be defined based on a base type which is a YANG built-in type

container Statement

see example from Line 18

defines interior (container node) in the schema tree
only contains child nodes, has no value
- - child nodes can be a leaf, lists, containers and leaf-lists

leaf Statement

see example from Line 27

defines a leaf node in the schema tree
its only one argument is the identifier
has no child nodes, has one value of a particular type
'type statement' is mandatory
See optional substatements available in (Section 7.6 https://www.hjp.at/doc/rfc/rfc6020.html#sec_1)

list Statement

see example from Line 35

defines an interior data node (list node) in the schema tree
its only one argument is the identifier
follows a block of substatements:
mandatory substatements:
- - 'key statement'

leaf-list Statement

see example from Line 41

array of leaf nodes
one value of a particular type per leaf
its only one argument is the identifier

...

Code Block

language	text

sampleExtension locations:
     +-- address* [state]
        +-- state string
        +-- city? string

Existing YANG parser in CPS

(Please see https://wiki.onap.org/display/DW/Existing+Yang+Parser)

OpenDayLight Yang tools recognises YANG extensions

Contains interface which has methods to access data of a YANG extension statement

Code Block

language	java
theme	Eclipse
title	ExtensionDefinition

package org.opendaylight.yangtools.yang.model.api;


import org.opendaylight.yangtools.yang.model.api.stmt.ExtensionEffectiveStatement;


public interface ExtensionDefinition extends SchemaNode, EffectiveStatementEquivalent<ExtensionEffectiveStatement> {


    String getArgument();


    boolean isYinElement();

}

Implementing Class
- - Class

Versions Compared

Old Version 12

New Version 13

Key

Overview

Basic YANG statements

Existing YANG parser in CPS

Page Comparison

Versions Compared

Old Version 12

New Version 13

Key

Overview

Basic YANG statements

Existing YANG parser in CPS