problem with Serialization JSON with children

[former_member553037]

Hello guys,

I need to deserialize a JSON that containts children or hierarchical/recursive data, to do this I am follow example from SAP WIKI: https://wiki.scn.sap.com/wiki/display/Snippets/One+more+ABAP+to+JSON+Serializer+and+Deserializer

In that link there is a example called: Serialization/deserialization of hierarchical/recursive data

I am triying to do that example but I dont understand this line:

lo_child LIKE lo_data.

I know its a variable declaration but object lo_data not exists on the example, and its not on dicionary data types, could anyone can explain me?

TYPES:
  BEGIN OF ts_node,
    id        TYPE i,
    children  TYPE STANDARD TABLE OF REF TO data WITH DEFAULT KEY,
  END OF ts_node.

DATA: lv_exp    TYPE string,
      lv_act    TYPE string,
      ls_data   TYPE ts_node,
      lr_data   LIKE REF TO ls_data.

ls_data-id = 1.

CREATE DATA lr_data.
lr_data->id = 2.
APPEND lr_data TO ls_data-children.

lv_exp = '{"ID":1,"CHILDREN":[{"ID":2,"CHILDREN":[]}]}'.
lv_act = /ui2/cl_json=>serialize( data = ls_data ).
cl_aunit_assert=>assert_equals( act = lv_act exp = lv_exp msg = 'Serialization of recursive data structure fails' ).


CLASS lcl_test DEFINITION FINAL.
  PUBLIC SECTION.
    DATA: id TYPE i.
    DATA: children TYPE STANDARD TABLE OF REF TO lcl_test.
ENDCLASS.


DATA: lo_act    TYPE REF TO lcl_test,
      lo_exp    TYPE REF TO lcl_test,
      lv_json   TYPE string,
      lo_child  LIKE lo_data.

CREATE OBJECT lo_exp.

lo_exp ->id = 1.

CREATE OBJECT lo_child.
lo_child->id = 2.
APPEND lo_child TO lo_exp->children.

lv_json = /ui2/cl_json=>serialize( data = lo_exp ).
ui2/cl_json=>deserialize( EXPORTING json = lv_json CHANGING data =  lo_act ).

[Sandra_Rossi]

To make it valid, I replaced the line with:

      lo_child  TYPE REF TO lcl_test.