| Recursion with Loop Checking
in SAP
* This program can be a model for any ABAP recursion. * This is often needed to navigate down hierarchical data. * One example is BOM. * Important point is to chack for stack overflow * and give RIGHT MESSAGE so that corrective action can be taken. *&---------------------------------------------------------------------* * Sample Program Showing Recursion in ABAP * Simple BOM Tree walking in ABAP * Takes Care of Diagnostics as well - detects Loops * Hence never experience Stack Overflow! *&---------------------------------------------------------------------* *&---------------------------------------------------------------------* * http://www.erpgreat.com/abap/reincarnation-of-reuse-alv-fieldcatalog-merge.htm * has INCLUDE zjncinclude with FORM zjnc_dump_list *&---------------------------------------------------------------------* * Author Jayanta Narayan Choudhuri * Flat 302 * 395 Jodhpur Park * Kolkata 700 068 * Email sss@cal.vsnl.net.in * URL: http://www.geocities.com/ojnc REPORT zjncrecursion. INCLUDE zjncinclude. " From www.erpgreat.com TABLES: makt. CONSTANTS: maxlevels TYPE i VALUE 10. TYPES: BEGIN OF ty_usage, parent TYPE makt-matnr, child TYPE makt-matnr, usage TYPE mseg-menge, END OF ty_usage. DATA: wa_usage TYPE ty_usage, it_usage TYPE STANDARD TABLE OF ty_usage. " USAGE data TYPES: BEGIN OF ty_stack, level TYPE h_level, matnr TYPE makt-matnr, menge TYPE mseg-menge, END OF ty_stack. DATA: istackpos TYPE i, wa_stack TYPE ty_stack, it_stack TYPE STANDARD TABLE OF ty_stack. "BOM Stack TYPES: BEGIN OF ty_reqd, matnr TYPE makt-matnr, menge TYPE mseg-menge, END OF ty_reqd. DATA: wa_reqd TYPE ty_reqd, it_reqd TYPE STANDARD TABLE OF ty_reqd. "NET Requirement of RAW Material PARAMETERS: p_build TYPE makt-matnr, "Target to Build p_menge TYPE mseg-menge. "Quantity to Build INITIALIZATION. PERFORM f_usage_data. START-OF-SELECTION. istackpos = 0. MOVE istackpos TO wa_stack-level. MOVE p_build TO wa_stack-matnr. MOVE p_menge TO wa_stack-menge. APPEND wa_stack TO it_stack. " 1st PUSH PERFORM f_explode USING p_build. SORT it_reqd BY matnr. PERFORM zjnc_dump_list USING 'IT_REQD' 'WA_REQD' 'Net RAW Requirement'. *&--------------------------------------------------------------------* *& Form f_Explode *&--------------------------------------------------------------------* FORM f_explode USING p_pmatnr. DATA: icount TYPE i, totalreq TYPE mseg-menge. istackpos = istackpos + 1. " PUSH IF istackpos GE maxlevels. PERFORM f_dumpstack. " terminate LEAVE PROGRAM. ENDIF. icount = 0. LOOP AT it_usage INTO wa_usage WHERE parent = p_pmatnr. icount = icount + 1. MOVE istackpos TO wa_stack-level. MOVE wa_usage-child TO wa_stack-matnr. MOVE wa_usage-usage TO wa_stack-menge. APPEND wa_stack TO it_stack. " PUSH PERFORM f_explode USING wa_usage-child. ENDLOOP. IF icount = 0. " then LEAF totalreq = '1.0'. LOOP AT it_stack INTO wa_stack. totalreq = totalreq * wa_stack-menge. ENDLOOP. MOVE p_pmatnr TO wa_reqd-matnr. MOVE totalreq TO wa_reqd-menge. COLLECT wa_reqd INTO it_reqd. ENDIF. DELETE it_stack INDEX istackpos. " POP istackpos = istackpos - 1. " POP ENDFORM. "f_Explode *&--------------------------------------------------------------------* *& Form f_dumpstack *&--------------------------------------------------------------------* FORM f_dumpstack. PERFORM zjnc_dump_list USING 'IT_STACK' 'WA_STACK' 'LOOP in BOM STACK'. ENDFORM. "f_dumpstack *&--------------------------------------------------------------------* *& Form f_usage_data for Hungry Bengali ABAPer in Kolkata *&--------------------------------------------------------------------* FORM f_usage_data. MOVE 'FISHCURRY' TO wa_usage-parent. MOVE 'SPICES' TO wa_usage-child. MOVE 10 TO wa_usage-usage. APPEND wa_usage TO it_usage. MOVE 'FISHCURRY' TO wa_usage-parent. MOVE 'MIRCHI' TO wa_usage-child. MOVE 5 TO wa_usage-usage. APPEND wa_usage TO it_usage. MOVE 'FISHCURRY' TO wa_usage-parent. MOVE 'ALOO' TO wa_usage-child. MOVE 8 TO wa_usage-usage. APPEND wa_usage TO it_usage. MOVE 'SPICES' TO wa_usage-parent. MOVE 'MIRCHI' TO wa_usage-child. MOVE 2 TO wa_usage-usage. APPEND wa_usage TO it_usage. MOVE 'SPICES' TO wa_usage-parent. MOVE 'JEERA' TO wa_usage-child. MOVE 3 TO wa_usage-usage. APPEND wa_usage TO it_usage. MOVE 'SPICES' TO wa_usage-parent. MOVE 'HALUD' TO wa_usage-child. MOVE 7 TO wa_usage-usage. APPEND wa_usage TO it_usage. ENDFORM. "f_usage_dataABAP Tips by : Jayanta Narayan Choudhuri Author Email: sss@cal.vsnl.net.in Author Website: http://www.geocities.com/ojnc
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