YAJLINTO error ; Reason Code 14

[HMiller]

Hello,

I have a JSON message where a variable could alternatively contains a value or a Json string itself.


This is the RPGLE Data structure to MAP json data.




In the example below everything works fine because "name" and "value" are properly mapped into the RPGLE data structure



In this example below "value" contains a Json string itself named "daterange".

There ia an extra level and I would like to parse "value" as a standard rpgle variable.
I will then scan "value" variable for "{daterange:" value and from there extract "endDate" and "startDate" via a new RPGLE structure.





I would like to know if this is possibile via YAJLINTO parser.

Thank you,

Giovanni

[Scott Klement]

Hi HMiller,

In this example, value can be either a number or an object (at least, based on your example.) Unfortunately, this dives into the limits of an RPG -- RPG does not have the concept of a variable that can sometimes be one data type and sometimes be another. This sort of thing is commonplace in "weakly typed" languages such as JavaScript, Python, or PHP and is difficult (if not impossible) in strongly typed languages (RPG, Cobol, C, Java, etc)

Since DATA-INTO is strictly a feature of RPG for mapping into a data structure that's determined at compile-time, you really can't use DATA-INTO here.

What you CAN do is call Yajl's subprocedures. This is no problem at all for that. This is off the top of my head, untested, and I don't expect that it is 100% complete

  docNode = yajl_stdin_load_tree(*on: errMsg);
  if docNode = *null;
    // handle error
  endif;

  filterNode = yajl_obj_get(docNode: 'filtersvalue');
  if filterNode = *null;
    // error: there was no 'filtersvalue'
  endif;

  i=0;
  dow YAJL_ARRAY_LOOP(filterNode: i: elemVal);

    nameNode = yajl_obj_get(elemVal: 'name');
    if nameNode = *null;
      name = '';
    else;
      nameNode = yajl_get_string(name);
    endif;

    startDate = *loval;
    endDate   = *hival;
    value     = 0;

    valueNode = yajl_obj_get(elemVal: 'value');
    if YAJL_IS_OBJECT(valueNode);
      rangeNode = yajl_obj_get(valueNode: 'dateRange');
      if rangeNode <> *null;
        startDate = yajl_obj_get(rangeNode: 'startDate');
        endDate   = yajl_obj_get(rangeNode: 'endDate'  );
      endif;
    elseif YAJL_IS_NUMBER(valueNode);
      value = yajl_get_number(valueNode);
    endif;

    // process this array element
  
  enddo;

  yajl_tree_free(docNode);

Hope that makes sense.