Intro to Program Development

1. Intro to Program Development • Develop complete program specs • Design the program • Create required CICS table entries • Create the BMS mapset • Code the program • Compile and Test the program • Document the program CICS-Dev

2. Program Specifications • Usually “Up to You!” • Program overview (Narrative) • Screen layout for each map (usually 1) • COPY members needed (if any) • Editing rules, Decision Tables • Files, DB/2 Tables read/updated CICS-Dev

3. Program Design • Critical! Can save hours (days!) • PSEUDO-CONVERSATIONAL (different!) • Event Driven - Major Functions • Processing Summary • Details processing for each response • Structure Chart, or ‘Table’ CICS-Dev

4. Create CICS Table Entries • PCT = Program Control Table • TRANS-ID assigned to Program • PPT = Processing Program Table (2) • COBOL Program • Mapset - Assembler Program • FCT = File Control Table • FILE(s) used by Program • Usually done by Systems Programmer CICS-Dev

5. Create the BMS Mapset • Defines the MAP(s) used by program • MAP provides for screen formatting • MAPSET is group of screens (1 or more) • Normally only one MAP per MAPSET • Only three macro’s used to create MAP • Usually a ‘Screen Generator’ is used CICS-Dev

6. Code the Program • Uses standard COBOL code (almost!) • Also uses CICS Commands • To include a CICS Command: • EXEC CICS • CICS Command (with PARAMETERS) • END-EXEC CICS-Dev

7. Compile Program • Special CICS Pre-compiler • CICS command-level translator • Converts CICS commands to COBOL • Creates listing with possible errors • Changes CICS lines to comments • Compiled by standard COBOL Compiler • Another listing with possible errors CICS-Dev

8. Test Program • Create test plan (Possible inputs) • Sign on to CICS (CESN) • Verify MAP is working (with CECI) • Test all conditions of program (CEDF) • NEWCOPY if changes made (CEMT) • Sign off of CICS (CESF) CICS-Dev

9. Document Program • Specifications and Listing (Sometimes!) • Every shop has set of ‘Standards’ • Some shops require both: • SYSTEM Documentation (for Maintenance) • USER Guide (Instructions for use) • ‘HELP’ screens sometimes used for user • Should not be last step! CICS-Dev

10. Creating a BMS MAPSET • 3270 is FIELD oriented display • Screen divided into user defined fields • Each field has CHARACTERISTICS • Determined by ATTRIBUTE BYTES • (First character of each field!) • Displayed as a space, but NOT available CICS-Dev

11. Creating a BMS MAPSET • Field starts at position after attribute • Attribute Byte determines the fields characteristics • Basic Attributes are: • Protection – allows user to key data • Intensity – normal or high • Shift – numeric or alphanumeric CICS-Dev

12. Protection Attribute • Protected – user can’t key data in field • Unprotected – user allowed to key data • Auto-Skip – cursor skips to next field • Used to mark end of data entry field • Cursor automatically moves to next field CICS-Dev

13. Intensity Attribute • Normal – shown normal intensity • Bright – shown in high intensity • No-display – not shown (background) • Used for password entry • Also used to ‘hide’ data on screen CICS-Dev

14. Shift Attribute • Alphanumeric – allows most characters • Numeric – only numeric characters • Not usually used – (CICS level error) • Multiple periods can be entered – error • Use Alpha and test in program! CICS-Dev

15. Attribute Byte Format 0 1 2 3 4 5 6 7 Bit Function Values 0-1 Depends on bits 2 - 7 See ATTR copylib 2-3 Protection and Shift 00 – Unprot alpha 01 – Unprot numeric 10 – Protected 11 – Protected skip 4-5 Intensity 00 – Normal 01 – Normal 10 – Bright 11 – No display 6 Reserved Must be 0 7 Modified Data Tag 0 – Field not modified 1 – Field was modified CICS-Dev

16. Extended Attributes • Allow Extra Colors: • Blue, Red, Pink, Green, • Turquoise, Yellow and White • Highlighting • Blinking, Reverse Video, Underlining • Validation • Must fill, Must enter, Trigger • Symbols • Up to six alternate character sets CICS-Dev

17. More terminology • PHYSICAL MAP – load module • Result of Assembly • Contains table of screen locations of data • Also contains attributes of each field • SYMBOLIC MAP – Copy library member • Result of Assembly • Usually used in COBOL program • You can create your own – if careful! CICS-Dev

18. Coding a BMS Mapset • Only need two Assembler commands • PRINT NOGEN (Not for AS400) • END • And three BMS MACRO Instructions • DFHMSD – Map Set Definition • DFHMDI – Map Definition • DFHMDF – Field (Attribute byte) Definition CICS-Dev

19. PRINT NOGEN and END • PRINT NOGEN should be the first line • Assembler will NOT print generated code • If omitted, you get much longer listing! • END – must be the last line of MAPSET • Informs Assembler – no more lines CICS-Dev

20. DFHMSD Macro VISnqq DFHMSD TYPE=&SYSPARM, X LANG=COBOL, X MODE= INOUT, X TERM=3270-2, X CTRL=FREEKB, X STORAGE=AUTO, X DSATTS=(COLOR,HILIGHT), X MAPATTS=(COLOR,HIGHLIGHT), X TIOAPFX=YES CICS-Dev

21. DFHMDI Macro VIDSnM1 DFHMDI SIZE=(24,80), X LINE=1, X COLUMN=1 CICS-Dev

22. DFHMDF Macro FLDNM DFHMDF POS=(line,col), X LENGTH=nn, X ATTRB=(unPROT), X COLOR=BLUE, X INITIAL=‘init value’ CICS-Dev

23. ATTRB Parameter • BRT High intensity display • NORM Normal intensity • DRK Not displayed (Hidden) • PROT Protected – no data keyed • UNPROT Data may be keyed in • IC Initial cursor position • FSET MDT set ON for field CICS-Dev

24. The Symbolic Map • Copy member created by Assembly • Use COPY statement in COBOL • Maximum of 7 character field names • MAPGEN adds the 8th (last) character • Fine for Assembler–Marginal in COBOL • You can code your own – if careful! CICS-Dev

25. Symbolic Map Suffix List • I The INPUT data field • O The OUTPUT data field (Same loc I) • L Binary Halfword-S9(4) COMP Nbr chars data returned in input field • F Char w/’80’ if field was cleared • A Char w/attrb for output (Same loc F) • C/H Used for Color and/or Highlighting CICS-Dev

26. Pseudo-Conversational • An on-line program that actually ended while appearing to wait for a response. • Single-user systems are ‘conversational’ • System waits for operator to enter data • Single user system - nothing else to do • Multi-user system can’t waste the time • 3270 screen handles operator activity CICS-Dev

27. Pseudo-Conversational • Conversational program remains in storage during entire interaction. • Pseudo-conversational program only in storage for a few seconds each action. • Many more users can be processed • Storage used more efficiently • Minor complication to programs! CICS-Dev

28. Pseudo-Conversational • Terminal handles operator entry • Attention Key signals CICS screen ready • Enter, PF, PA, or Clear Key - (Event) • CICS reloads program (Virtual Storage) • Program start at BEGINNING every time • You must keep up with where user is • User unaware that program restarted CICS-Dev

29. Sample CICS Scenario • Transaction ID Entered • Looked up in PCT - Program loaded • Program displays initial map and ends • User enters data and hits ‘Enter’ key • Program reloaded (from CICS storage) • Receives data from screen • Processes data • Sends response back to screen • Returns to CICS CICS-Dev

30. CICS Input/Output • CICS handles all I/O • Treat screen as simple file (one record) • Can Read Screen – RECEIVE MAP • Can Write Screen – SEND MAP • Can Return to CICS with ID of Program to execute next time user keys AID key • Return without TRANS-ID, Exits to CICS CICS-Dev