XML Parser

XML related API has been around for some time now in PeopleSoft and this post is not discussing anything new. Just something that I wanted to pen down for future reference. 

So recently I have been working on a requirement where in I have to parse out a XML response and fetch data values in order to process them further. In this case the same tag element names repeat throughout the XML message and there are multiple levels in the message. The requirement was to traverse each "item" tag and fetch the value for "key" and "value" tags.

Format of the XML message is as shown below.

<?xml version="1.0" encoding="UTF-8"?> <root> <level1> <level2> <level3> <item> <key>FieldName1</key> <value>Value1</value> <type>String</type> </item> <item> <key>FieldName2</key> <value>Value2</value> <type>Date</type> </item> <item> <key>FieldName3</key> <value>Value3</value> <type>Number</type> </item> </level3> </level2> </level1> </root>



Wrote two methods, first one is way longer than the second one.
For both methods I am passing the "field_name_value" and getting back the &fieldvalue value.


Method one - longer.


Local XmlDoc &NewHireXMLDoc;
Local XmlNode &root, &level1, &level2, &level3, &item;
Local number &z, &y, &x, &w, &v;
Local string &sResp, &fieldvalue;
Local boolean &bRet;


rem &sResp is the XML message in string form;
   
&NewHireXMLDoc = CreateXmlDoc();
&bRet = &NewHireXMLDoc.ParseXmlString(&sResp);

&rootNode = &NewHireXMLDoc.DocumentElement;

For &z = 1 To &rootNode.ChildNodeCount
   If &root.GetChildNode(&z).NodeName = "level1" Then
      &level1= &root.GetChildNode(&z);
      For &y = 1 To &level1.ChildNodeCount
         If &level1.GetChildNode(&y).NodeName = "level2" Then
            &level2= &level1.GetChildNode(&y);
            For &x = 1 To &level2.ChildNodeCount
               If &level2.GetChildNode(&x).NodeName = "level3" Then
                  &level3 = &level2.GetChildNode(&x);
                  For &w = 1 To &level3.ChildNodeCount
                     If &level3.GetChildNode(&w).NodeName = "item" Then
                        &item = &level3.GetChildNode(&w);
                        For &v = 1 To &item.ChildNodeCount
                           If &item.GetChildNode(&v).NodeName = "key" And
                                 &item.GetChildNode(&v).NodeValue = "field_name_value" Then
                              &fieldvalue = &item.GetChildNode(&v + 1).NodeValue;
                              &v = &v + 1;
                           End-If;
                       End-For;
                     End-If;
                  End-For;
               End-If;
            End-For;
         End-If;
      End-For;
   End-If;
End-For;



Method two - shorter

Local XmlDoc &NewHireXMLDoc;
Local string &sResp, &fieldvalue;
Local boolean &bRet;

Local array of XmlNode &items;
Local number &y, &z;

rem &sResp is the XML message in string form;
   
&NewHireXMLDoc = CreateXmlDoc();
&bRet = &NewHireXMLDoc.ParseXmlString(&sResp);


&items = &NewHireXMLDoc.DocumentElement.FindNodes("level1/level2/level3/item");
   
   For &z = 1 To &items.Len
      For &y = 1 To &items [&z].ChildNodeCount
         
         If &items [&z].GetChildNode(&y).NodeName = "key" And
               &items [&z].GetChildNode(&y).NodeValue = "field_name_value" Then
            &fieldvalue = &items [&z].GetChildNode(&y + 1).NodeValue;
            Break;
         End-If;
      End-For;

   End-For;

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.