Discovering a Hidden Gem :Generate Simple Transformation for XML in ABAP

Even in its most nascent form, this less known wizard of simple transformation, could be really useful for ABAP developers. I think, ABAP developers would love to have a graphical utility to generate simple transformation/XSLT code.

Almost a year back,  I was writing some happy-code to consume an external web service from ABAP. As the web service was returning the result data in the form of an XML string, I ended up writing a Simple Transformation to get the values in ABAP internal table.

Consuming webservice from ABAP is not the topic of this post but if you need help on this then please check the blogs on SDN. However, If you need to post an answer on a twitter-interview ( similar to a telephonic interview but held on twitter ) then there you go :

Xn SE80->Repository Browser->Enterprise Services->[ right click to bring the context menu ] -->Create Proxy [ use WSDL URL e.g. http://www.webservicex.net/uklocation.asmx?WSDL to generate proxy through wizard ]. Xn LPCONFIG to configure the logical port.

Back to the topic, I spotted this magic-stick in Simple Transformation editor [ Transaction XSLT_TOOL ] and tried to make it work. But could not decipher and wrote the ST manually, instead. Interestingly, I could not find any information  about this so called "Edit Simple Transformation Graphically" feature. In my defence, I searched on SAP OSS, SAP Help & SDN. There you go ...Well search feature on SAP Sites.. is great anyway ;)

A year later, I just happened to be adoring ( developers do this often ) my old code and it reminded me of this utility. I tried figuring out once again and managed to discover something worth sharing.

Service proxy call provides data in the form of XML result. Code for proxy call is as below:

CREATE OBJECT LO_UK_LOCATION.
TRY.
lv_input-POST_CODE = p_post.

CALL METHOD LO_UK_LOCATION->GET_UKLOCATION_BY_POST_CODE
  EXPORTING
    INPUT  = lv_input
  IMPORTING
    OUTPUT = lv_output.

 CATCH CX_AI_SYSTEM_FAULT .
   WRITE : 'CX_AI_SYSTEM_FAULT'.
 CATCH CX_AI_APPLICATION_FAULT .
   WRITE : 'CX_AI_APPLICATION_FAULT'.
ENDTRY.

Now the result variable lv_output will be having the data in the form of an XML string as below.
Tip: You can use a function module SCOL_TRACE_SHOW_XML to show the XML data on screen.

<NewDataSet>
                    <Table>
                              <Town>Balthangie</Town>
                              <County>Aberdeenshire</County>
                              <PostCode>AB53</PostCode>
                     </Table>
                     <Table>
                              <Town>Bankhead</Town>
                              <County>Aberdeenshire</County>
                              <PostCode>AB51</PostCode>
                     </Table>
</NewDataSet>

In order to transform the XML to ABAP internal table, I decided to use Simple Transformation. Now I will generate the simple transformation as below:

1. Create Table Type ZNEWDATASET in transaction SE11. The hierarchy structure should be compatible with the XML hierarchy.
   
   
   
   
2. Now create the ST program in transaction XSLT_TOOL. Spot the magic stick in the editor menu.
   
   
   
3.  Click on 'Edit Simple Transformation Graphically' button (magic stick) and you will get the editor as below. Create a new root (right click - context menu ) in "Data Roots" section. I've named it NEWDATASET but the important thing is to enter the correct type, created earlier.
   
   
   
4. Now you can see the data root hierarchy as below. Drag and Drop the NEWDATASET root on right panel ( Simple Transfromation ). It automaically generates the ST nodes corresponding to the ABAP structure. However, you need to adjust the names as per the XML element names.
   
   
5. Now adjust the names in ST panel as per actual XML element names.
   
   
   
6. Save and Activate. The ST program (Z_TEST), generated by the utility, is as below:
   

   <?sap.transform simple?>
   <tt:transform xmlns:tt="http://www.sap.com/transformation-templates" xmlns:ddic="http://www.sap.com/abapxml/types/dictionary" xmlns:def="http://www.sap.com/abapxml/types/defined">
       <tt:root name="NEWDATASET" type="ddic:ZNEWDATASET"/>
           <tt:template>
                 <NewDataSet>
                       <tt:loop ref=".NEWDATASET">
                             <Table>
                                        <Town tt:value-ref="TOWN"/>
                                        <County tt:value-ref="COUNTY"/>
                                       <PostCode tt:value-ref="POST_CODE"/>
                             </Table>
                       </tt:loop>
                  </NewDataSet>
            </tt:template>
   </tt:transform>

7. Now use the code below to get data into ABAP internal table.
   
   

   data : result type ZNEWDATASET, "itab of table type ZNEWDATASET
          wa_result like line of result.
   
           call transformation Z_TEST 
             source xml lv_output-GET_UKLOCATION_BY_POST_CODE_R
             result     newdataset = result[].
   
   LOOP AT result into wa_result.
     WRITE :/ wa_result-TOWN, wa_result-COUNTY, wa_result-POST_CODE.
   ENDLOOP.
   

It seems to be a very useful utility. I hope this will be further enhanced by SAP or the SAP Community.
By the way, I checked this on SAP ECC6.0. I will try to explore further for complex XML e.g. elements having attributes.

Please do add your inputs, if you managed to check this out or have done this before.

Updated: 
SAP Help document for ST is at http://help.sap.com/abapdocu/en/ABENABAP_XML.htm

* It's better to Display XML from ABAP as below :
cl_abap_browser=>show_xml( EXPORTING xml_string = xml_string ).