CPS-870: Align CPS-Core output with SDN-C output

Comparison of CPS core output before modification to NCMP passthrough operation output

The following details were used to compare and analyze the current CPS core output to NCMP passthrough operation output

Model	bookstore.yang
Data	bookstore.json
CPS core endpoint	/v1/dataspaces/{dataspace-name}/anchors/{anchor-name}/node
NCMP Passthrough operation	/v1/ch/{cm-handle}/data/ds/ncmp-datastore:passthrough-running

Scenario 1: XPath is pointing to root i.e. '/' CPS = '/'
	NCMP Passthrough operation output	CPS Core output
Response	Expand source { "stores:bookstore": { "bookstore-name": "Chapters", "categories": [ { "code": "02", "books": [ { "title": "The Golden Compass", "price": "699", "pub_year": 1995, "lang": "en", "authors": [ "Philip Pullman" ] } ], "name": "kids" }, { "code": "01", "books": [ { "title": "Feersum Endjinn", "price": "895", "pub_year": 1994, "lang": "en", "authors": [ "Iain M. Banks" ] }, { "title": "Far Horizons", "price": "1099", "pub_year": 1999, "lang": "en", "authors": [ "david Brin", "Ursula K. Le Guin", "Rober Silverberg", "Orson Scott Card", "Greg Bear", "Joe Haldeman", "Dan Simmons" ] } ], "name": "SciFi" } ] } }	Expand source { "bookstore": { "bookstore-name": "Chapters", "categories": [ { "code": "01", "name": "SciFi", "books": [ { "lang": "en", "price": 895, "title": "Feersum Endjinn", "authors": [ "Iain M. Banks" ], "pub_year": 1994 }, { "lang": "en", "price": 1099, "title": "Far Horizons", "authors": [ "david Brin", "Ursula K. Le Guin", "Rober Silverberg", "Orson Scott Card", "Greg Bear", "Joe Haldeman", "Dan Simmons" ], "pub_year": 1999 } ] }, { "code": "02", "name": "kids", "books": [ { "lang": "en", "price": 699, "title": "The Golden Compass", "authors": [ "Philip Pullman" ], "pub_year": 1995 } ] } ] } }
Scenario 2: Container XPath i.e '/bookstore' CPS = '/bookstore' NCMP = '/ncmp/v1/ch/PNFDemo/data/ds/ncmp-datastore:passthrough-running?resourceIdentifier=stores:bookstore'
	NCMP Passthrough operation output	CPS Core output
Response	Expand source	Expand source { "bookstore": { "bookstore-name": "Chapters", "categories": [ { "code": "01", "name": "SciFi", "books": [ { "lang": "en", "price": 1099, "title": "Far Horizons", "authors": [ "david Brin", "Ursula K. Le Guin", "Rober Silverberg", "Orson Scott Card", "Greg Bear", "Joe Haldeman", "Dan Simmons" ], "pub_year": 1999 }, { "lang": "en", "price": 895, "title": "Feersum Endjinn", "authors": [ "Iain M. Banks" ], "pub_year": 1994 } ] }, { "code": "02", "name": "kids", "books": [ { "lang": "en", "price": 699, "title": "The Golden Compass", "authors": [ "Philip Pullman" ], "pub_year": 1995 } ] } ] } }
Scenario 3: List attributes XPath CPS = '/bookstore/categories[@code='02']' NCMP = '/ncmp/v1/ch/PNFDemo/data/ds/ncmp-datastore:passthrough-running?resourceIdentifier=stores:bookstore/categories=02'
	NCMP Passthrough output	CPS Core output
Response	Expand source { "stores:categories": [ { "code": "02", "books": [ { "title": "The Golden Compass", "price": "699", "pub_year": 1995, "lang": "en", "authors": [ "Philip Pullman" ] } ], "name": "kids" } ] }	Expand source { "categories": { "code": "02", "name": "kids", "books": [ { "lang": "en", "price": 699, "title": "The Golden Compass", "authors": [ "Philip Pullman" ], "pub_year": 1995 } ] } }

Modifying CPS Core output

Parsing a model with prefix

Using the following test the given data above was used to see that prefixed is valid with the current YangTools that CPS uses

    def 'Parsing a valid Json String.'() {
        given: 'a yang model (file)'
            def jsonData = org.onap.cps.TestUtils.getResourceFileContent('bookstore.json')
        and: 'a model for that data'
            def yangResourceNameToContent = TestUtils.getYangResourcesAsMap('bookstore.yang')
            def schemaContext = YangTextSchemaSourceSetBuilder.of(yangResourceNameToContent).getSchemaContext()
        when: 'the json data is parsed'
            NormalizedNode<?, ?> result = YangUtils.parseJsonData(jsonData, schemaContext)
        then: 'the result is a normalized node of the correct type'
            result.nodeType == QName.create('org:onap:ccsdk:sample', '2020-09-15', 'bookstore')
    }

The test above passed for the used data.

The following data wherein the list attribute also contains a prefix was also tested to see if the YangTools parser will fail. The same result as the above test was collected.

{
   "stores:bookstore":{
      "bookstore-name": "Chapters",
      "stores:categories": [
         {
            "code": "01",
            "name": "SciFi",
            "books": [
               {
                  "authors": [
                     "Iain M. Banks"
                  ],
                  "lang": "en",
                  "price": "895",
                  "pub_year": "1994",
                  "title": "Feersum Endjinn"
               },
               {
                  "authors": [
                     "Ursula K. Le Guin",
                     "Joe Haldeman",
                     "Orson Scott Card",
                     "david Brin",
                     "Rober Silverberg",
                     "Dan Simmons",
                     "Greg Bear"
                  ],
                  "lang": "en",
                  "price": "1099",
                  "pub_year": "1999",
                  "title": "Far Horizons"
               }
            ]
         },
         {
            "name": "kids",
            "code": "02",
            "books": [
               {
                  "authors": [
                     "Philip Pullman"
                  ],
                  "lang": "en",
                  "price": "699",
                  "pub_year": "1995",
                  "title": "The Golden Compass"
               }
            ]
         }
      ]
   }
}

Building the data node

DataNodeBuilder class was modified to add the method 'withModuleName()' which adds a module name attribute to the DataNode object being built.

When the buildFromAttributes() method is called it then calls the added method addModulePrefixToXpath(moduleName).

addModulePrefixToXpath(moduleName) contains the following logic

        if xpath contains '['
           insert module name prefix after the last '/'
        else
            insert module name prefix after the first character ('/')

Results of modifying cps core output through DataNodeBuilder

Xpath

Response

/

{
  "stores:bookstore": {
    "bookstore-name": "Chapters",
    "categories": [
      {
        "code": "02",
        "name": "kids",
        "books": [
          {
            "lang": "en",
            "price": 699,
            "title": "The Golden Compass",
            "authors": [
              "Philip Pullman"
            ],
            "pub_year": 1995
          }
        ]
      },
      {
        "code": "01",
        "name": "SciFi",
        "books": [
          {
            "lang": "en",
            "price": 1099,
            "title": "Far Horizons",
            "authors": [
              "david Brin",
              "Ursula K. Le Guin",
              "Rober Silverberg",
              "Orson Scott Card",
              "Greg Bear",
              "Joe Haldeman",
              "Dan Simmons"
            ],
            "pub_year": 1999
          },
          {
            "lang": "en",
            "price": 895,
            "title": "Feersum Endjinn",
            "authors": [
              "Iain M. Banks"
            ],
            "pub_year": 1994
          }
        ]
      }
    ]
  }
}

/bookstore/categories[@code='02']

{
  "stores:categories": {
    "code": "02",
    "name": "kids",
    "books": [
      {
        "lang": "en",
        "price": 699,
        "title": "The Golden Compass",
        "authors": [
          "Philip Pullman"
        ],
        "pub_year": 1995
      }
    ]
  }
}

The DataNode built for the above tests will now contain a modified xPath containing the module name just like as follows:

Xpath parameter	Expected modified XPath set as data node XPath attribute
Example module name	stores
/bookstore	/stores:bookstore
/bookstore/categories[@code='02']	/bookstore/stores:categories[@code='02']

Open Issues

Issue	Description	Resolution
Child is in a different module	If the child is in a different module should it have a prefix
Output starts with non-root element	If the output starts with non-root element should it have a prefix
Backward incompatibility	Discuss backward incompatibility with stakeholders WiPro (E2E Slicing) Ericsson Bell (Bruno has confirmed that they are not impacted ?) Can YangTools parse it? if YangTools can parse it then this is not incompatible
Is this LEGAL YANG data