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

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

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

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

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 macros used to create MAP
• Usually a Screen Generator is used

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

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

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)

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!

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

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

12
Protection Attribute

• Protected user cant 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

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

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!

15
Attribute Byte Format
0
1
2
3
5
4
6
7
Bit Function Values 0-1 Reserved Must be
0 2-3 Protection and Shift 00 Unprot
alpha 01 Unprot numeric 10
Protected stop 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
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

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!

18
Coding a BMS Mapset

• Only need two Assembler commands
• PRINT NOGEN
• END
• And three BMS MACRO Instructions
• DFHMSD Map Set Definition
• DFHMDI Map Definition
• DFHMDF Field (Attribute byte) Definition

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

20
DFHMSD Macro

• MAPSET1 DFHMSD TYPESYSPARM, X
• LANGCOBOL, X
• MODE INOUT, X
• TERM3270-2, X
• CTRLFREEKB, X
• STORAGEAUTO, X
• TIOAPFXYES

21
DFHMDI Macro

• MAP1 DFHMDI SIZE(24,80), X
• LINE1, X
• COLUMN1

22
DFHMDF Macro

• FLDNM DFHMDF POS(line,col), X
• LENGTHnn, X ATTRB(PROT), X
• ignored here COLORBLUE, X
• INITIALinit value

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

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 AssemblerMarginal in COBOL
• You can code your own if careful!

25
Symbolic Map Suffix List

• I The INPUT data field
• O The OUTPUT data field (Same loc I)
• L Binary Halfword-S9(4) COMP that contains 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

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 cant waste the time
• 3270 screen handles operator activity

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!

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

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
• Receives data from screen
• Processes data
• Sends response back to screen
• Returns to CICS

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