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;

Creating JSON request for REST web services

PeopleSoft provides Document technology to be used to generate JSON request messages but in my experience they are very restrictive especially when working on integrating with 3rd party web services. So following is what I did to generate a JSON request message to post to a 3rd party REST web service. 

The request that I have to generate is in the following form.
[
   {
      "attrib1":"value1",
      "attrib2":"value2",
      "attrib3":{
         "attrib3_1":"values3_1",
         "attrib3_2":"values3_2",
         "attrib3_3":"values3_3",
         "attrib3_4":"values3_4"
      }
   }
]

I am running PT 8.57.x and at this time its not possible to build a document with the root node as an array as shown in the example below. Also I have nested compounds which is also a challenge, the parent compound does not have a label where as the child does. 
So to build something like above I am using the CreateJsonBuilder API provided by PeopleSoft.

Local JsonBuilder &jbldr = CreateJsonBuilder();
Local JsonArray &jArray;

Local string &json;
Local message &request, &response;
Local boolean &bRet;

&jbldr.StartArray(""); /* no label */
 &jbldr.StartObject(""); /* no label */
  &jbldr.AddProperty("attrib1", "value1");
  &jbldr.AddProperty("attrib2", "value2");
   &jbldr.StartObject("attrib3"); /* need a label */
    &jbldr.AddProperty("attrib3_1", "value3_1");
    &jbldr.AddProperty("attrib3_2", "value3_2");
    &jbldr.AddProperty("attrib3_3", "value3_3");
    &jbldr.AddProperty("attrib3_4", "value3_4");
   &jbldr.EndObject("attrib3"); /* closing out the compound or JSONObject */
 &jbldr.EndObject("");
&jbldr.EndArray("");


/* this will return the array just like what I want */
&jArray = &jbldr.GetRootNode().GetJsonObject().GetJsonArray("");
&json = &jArray.ToString();

Created a basic non-rowset based message and assigned that as the request message in my service operation. Use this method to set the content for the message segment for a non-rowset-based message only.

&bRet = &request.SetContentString(&json);
&response = %IntBroker.SyncRequest(&request);

That's it, works like a charm.