Creating Method Dynamically

This is my first post in this blog, well playing with ABAP I thought it could be cool to add methods to a class dynamically.  Am sharing with you a sample coding that just do that.

After searching the internet there are some reference to SBMIG_CREATE_CLASS_AND_TTYPES progam. Ideally the program creates a class/type dynamically. Tracing the code I found the following functions

• SEO_METHOD_CREATE_F_DATA: that creates a method definition in a class.
• SEO_PARAMETER_CREATE_F_DATA: that creates the method parameter
• SEO_METHOD_GENERATE_INCLUDE: that creates the code implantation.

There isn’t much of a documentation (or there is and I couldn’t find it) so I play with the coding and wrote a simple program that just adds a method to a static class. The program (see the code below) does not save the method, after executing the code the method does not exist. It creates a public static method call “Descr” on an existing class call ZCL_TEST. The new method returns a string ‘Test’.

Data: l_wa_method type vseomethod,
l_wa_method_source type seo_method_source,
seox_false type c
value ‘ ‘,
seox_true type c
value ‘X’,
l_wa_method_parameter type VSEOPARAM,
l_tbl_code type  RSWSOURCET,
l_wa_code type string,
mtdkey TYPE seocpdkey,
l_v_r(10) type c,
l_v_method_name type string VALUE ‘DESCR’,
l_o type REF TO object,
l_v_classname(60) type c value ‘ZCL_TEST’,
cfkey type SEOCLSKEY,
l_v_c type currkey,
l_v_genflag type c VALUE ‘ ‘
.

START-OF-SELECTION.

l_wa_method–clsname = l_v_classname.
l_wa_method–CMPNAME = l_v_method_name.
l_wa_method–DESCRIPT = ‘Testing Method’.
l_wa_method–version =  ‘1’.
l_wa_method–langu = sy–langu.
l_wa_method–MTDTYPE = ‘0’.
l_wa_method–MTDDECLTYP = ‘1’. “static method = 1- instance = 0
l_wa_method–EXPOSURE = ‘2’. “public = 2, private = 0, protected = 1
l_wa_method–state = ‘1’.
l_wa_method–REFCLSNAME = l_v_classname.
l_wa_method–REFINTNAME = l_v_classname.
l_wa_method–REFCMPNAME = l_v_method_name.

l_wa_method_parameter–clsname = l_v_classname.
l_wa_method_parameter–CMPNAME = l_v_method_name.
l_wa_method_parameter–SCONAME = ‘r_v_desc’.
l_wa_method_parameter–VERSION = ‘1’.
l_wa_method_parameter–PARDECLTYP = ‘3’.
l_wa_method_parameter–PARPASSTYP = ‘0’.
l_wa_method_parameter–TYPTYPE = ‘1’. ” like =0,  type=1, type ref=2
l_wa_method_parameter–TYPE = ‘char10’.

l_wa_method_source–CPDNAME = l_v_method_name.
l_wa_method_source–REDEFINE = ‘0’.
l_wa_code  = ‘ r_v_desc = ”Test 12121”.’ .
append l_wa_code to l_tbl_code.

l_wa_method_source–SOURCE  = l_tbl_code.

mtdkey–clsname = l_v_classname.
mtdkey–cpdname = l_v_method_name.

move-CORRESPONDING l_wa_method to  cfkey.
CALL FUNCTION ‘SEO_BUFFER_REFRESH’
EXPORTING
cifkey  = cfkey
version = ‘0’.

CALL FUNCTION ‘SEO_METHOD_CREATE_F_DATA’
EXPORTING
save   = seox_false
CHANGING
method = l_wa_method
EXCEPTIONS
OTHERS = 1.

CALL FUNCTION ‘SEO_PARAMETER_CREATE_F_DATA’
EXPORTING
save      = seox_false
CHANGING
parameter = l_wa_method_parameter
EXCEPTIONS
OTHERS    = 1.

CALL FUNCTION ‘SEO_METHOD_GENERATE_INCLUDE’
EXPORTING
mtdkey                  = mtdkey
force                   = ‘X’
redefine                = l_wa_method_source–redefine
implementation_expanded = l_wa_method_source–source
suppress_index_update   = ‘X’
suppress_corr           = ‘X’
EXCEPTIONS
OTHERS                  = 1.

call method ZCL_TEST=>(l_v_method_name)
RECEIVING
r_v_desc = l_v_r
.

write l_v_r.