JSON Parser

PeopleSoft has undocumented JSON related API and this post covers some of the routines that I have tried to dynamically parse a json response. I think this API calls were made available in PT 8.56.x as part of PeopleSoft's inbuilt integration with ElasticSearch. 

I am making a RESTful web service call to a service hosted by a 3rd party vendor from PeopleSoft; so PeopleSoft is a consumer of the service. Focus here is to parse the response from the service so I am not covering how the service is setup and the request part of the service. 

So I have two types of responses. Response 1 as shown below 

{

    "error": {

        "message": "Some message text",

        "detail": "detail text about the error"

    },

    "status": "failure"

}

and Response 2 as follows.

{

   "import_set":"Import set value",

   "staging_table":"tablename",

   "result":[

      {

         "status":"updated",

         "error_message":"Unable to format 01-01-2019 using format string yyyyMMdd  for field hire_dt"

      }

   ]

}

In Response 1, I has 2 children, viz "error" and "status", whereas Response 2 has 3 children, import_set, staging_table and result.

In Response 1, "error" is a JSonObject which has 2 more children, message and detail. In Response 2, "result" is a JSonArray which has 2 children status and error_message.

Local string &content, &propName, &propValue;

Local JsonParser &parser;

Local JsonObject &jsonRoot, &jsonDetails;

Local JsonArray &jArray;

Local boolean &ret; 

Local number &i, &j, &k, &l;

&parser = CreateJsonParser(); /* this is the undocumented API */

&ret = &parser.Parse(&content); /* &content is the json response as a string */

&jsonRoot = &parser.GetRootObject();

For &i = 1 To &jsonRoot.GetChildCount()
/* for Response 1, following will get status tag and its value */
/* for Response 2, following will get import_set, staging_table and its values */

   &propName = &jsonRoot.GetPropertyNameAt(&i);

   &propValue = &jsonRoot.GetProperty(&propName);

   /* if there is a nested value then its either JsonArray or JsonObject */

   Evaluate &propValue

   When = "JsonArray"
/* this will return status and error_message which are in Response 2 */

      &jArray = &jsonRoot.GetJsonArray(&propName);

      For &j = 1 To &jArray.Length()

         &jsonDetails = &jArray.GetJsonObject(&j);

         For &k = 1 To &jsonDetails.GetChildCount()

            &propName = &jsonDetails.GetPropertyNameAt(&k);

            &propValue = &jsonDetails.GetProperty(&propName);

         End-For;

      End-For;

      Break;

   When = "JsonObject"
/* this will return message and detail which are in Response 1 */

      &jsonDetails = &jsonRoot.GetJsonObject(&propName);

      &numCnt = &jsonDetails.GetChildCount();

      For &l = 1 To &jsonDetails.GetChildCount()

         &propName = &jsonDetails.GetPropertyNameAt(&l);

         &propValue = &jsonDetails.GetProperty(&propName);

      End-For;

      Break;

   When-Other;

      /* when not JsonArray or JsonObject, get prop name and value which is at root level */

      Break;

   End-Evaluate;

End-For;

Hope this helps.