ABAP and JSON

Horst,

thanks for your answer. Of course, XSLT maps XML to XML. I knew that.

In my question, the source was ABAP data, which means that the XML source format is asXML implicitly.

Also, in my question, the target format was a lo_json string writer, which means that the target XML format is implicitly asJSON.  So I am speaking of an XSLT transformation asXML to asJSON. So the XSLT transformation will produce a tree consisting of <object>, <str>, <array> ... elements and the like.

It is not necessary, as you wrote, that I first have to call the identity transformation explicitly, and in a second transformation to map the XML to JSON. Instead, I can directly work in one and only one XSLT transformation on the ABAP data, assuming them in asXML notation, and I can directly in this same XSLT transformation produce an asJSON XML output. This works fine in the non-reference case, and I have already developped various transformations of this type.

My only problem is with data references. Let me give you a simple example.

When you run the following test with a sample concrete "ref to" data object,

method test.

data: lo_json type ref to cl_sxml_string_writer,
         lt_t000 type ref to cts_t000_tab,
         lv_json type xstring.

   create data lt_t000.
   select * from t000 into table lt_t000->*.

   lo_json = cl_sxml_string_writer=>create( if_sxml=>co_xt_json ).
   call transformation id
     options
       data_refs = 'heap-or-create'
     source
       data     = lt_t000
     result xml
       lo_json.

   lv_json = lo_json->get_output( ).
   break-point.
endmethod.

Then you get the following JSON output:

{

  "DATA": { "%ref": "#d1" },

  "%heap": {

    "d1": {

      "%type": "dic:CTS_T000_TAB",

      "%val": [

        {

          "MANDT": "000",

          "MTEXT": "SAP AG Konzern",

          "ORT01": "Walldorf",

          "MWAER": "EUR",

          "ADRNR": "",

          "CCCATEGORY": "S",

          "CCCORACTIV": "2",

          ...

Actually, the impicit XML asJSON output is

<?xml version="1.0" encoding="utf-8"?>

<object>

<object name="DATA">

<str name="%ref">#d1</str>

</object>

<object name="%heap">

<object name="d1">

<str name="%type">dic:CTS_T000_TAB</str>

<array name="%val">

<object>

<str name="MANDT">000</str>

<str name="MTEXT">SAP AG Konzern</str>

<str name="ORT01">Walldorf</str>

... and so on

So the ABAP->JSON converter is able to deserialize the data and to produce the fragment

<object>

  <str name="MANDT">000</str>

  ...

and so on.

I am looking for an XSLT transformation ZDATA which produces the actual data to which the reference points, in a generic way, i.e. independent of the actual data type. (So I want to dereference the data object inside of the XSLT transformation.) In the example, I want to produce as part of the result the following JSON array

[

        {

          "MANDT": "000",

          "MTEXT": "SAP AG Konzern",

          "ORT01": "Walldorf",

          "MWAER": "EUR",

          "ADRNR": "",

          "CCCATEGORY": "S",

          "CCCORACTIV": "2",

...

  ].

Of course, as you proposed, I could evaluate the asABAP XML source fragment located below the asx:heap node (given by the XPath expression /asx:abap/asx:heap/*[@id = substring(./@href,2)] where the current node in asx:data is of reference type).

But then I should explicitly program the cases: Is this a table, a structure, a simple data object? Or is it nested (if yes: do recursion...)? And all this logic has obviously already been implemented in the ABAP -> JSON converter: As you see in the example, the %val element of the heap section already contains what I am looking for.

I hope that I could explain more clearly what I am looking for.

Thanks for having a second look at this.

Regards,

Rüdiger

Horst,

thanks for the answer. The XSDBOOLEAN type is a practical option, it saves you the work of writing an own transformation, you can use the identical transformation instead. It works well on  our SAPKB70211 system, as I just tested. 

Thanks & regards, Rüdiger