Natural Part1

7/28/2019 Natural Part1

1/34

FUNDAMENTALS OF NATURAL PROGRAMMING


2/34

Objective of the Session

The objective of this course is to understand thebasic programming concepts of Natural

Prerequisites :

Mainframe background (TSO/ISPF, JCL)


3/34

TOPICS OF INTEREST INTRODUCTION

NATURAL PROGRAMMING MODES

NATURAL OBJECTS

DATA AREAS

DEFINING DATA

STATEMENTS & OPERATORS & FUNCTIONS

USER DEFINED CONSTANTS

ARRAYS

CONDITIONAL & LOOPING STATEMENTS

PROGRAM & ROUTINE INVOKING STATEMENTS

SEQUENTIAL FILE HANDLING

SYSTEM VARIABLES & EDIT MASK


4/34

INTRODUCTION


5/34

ABOUT NATURAL Natural is a complete application development environment for designing,

developing and employing business-critical applications

It supports all popular platforms, including mainframes, Windows, Unix, andLinux

Programming Language Developed by Software AG

It has been used by enterprises around the world since it was introduced in1979

Fourth Generation Language

Has both Online and Batch features

Can access

Sequential files

ADABAS

DB2

Programming modes

Structured

Reporting


6/34

ADVANTAGES

Natural can be used to open up key information to clients and partners without

major redevelopment

Simple and efficient

Natural requires fewer lines of code for a given task than other development

languages

The language is easy to learn; developers new to Natural can be trained and

made productive in a matter of weeks


7/34

NATURAL PROGRAMMING MODES


8/34

Natural offers two ways of programming:

Reporting mode

Reporting mode is only useful for the creation of adhoc reports and small

programs which do not involve complex data and/or programming

constructs

Structured mode

Structured mode is intended for the implementation of complex

applications with a clear and well-defined program structure


9/34

Setting the Programming Mode

The default programming mode is set by the Natural administrator with the

profile parameter SM. You can change the mode by using the Natural system command

GLOBALS and the session parameter SM:

Structured Mode: GLOBALS SM=ON

Reporting Mode: GLOBALS SM=OFF


10/34

Functional Differences

The following major functional differences exist between reporting mode and

structured mode:

Syntax Related to Closing Loops and Functional Blocks

Closing a Processing Loop in Reporting Mode

Closing a Processing Loop in Structured Mode

Location of Data Elements in a Program

Database Reference


11/34

Reporting

Mode:

(CLOSE) LOOP and DO ... DOEND statements are used for this purpose.

END-... statements (except END-DEFINE, END-DECIDE and END-

SUBROUTINE)

cannot be used.

Structured

Mode:

Every loop or logical construct must be explicitly closed with a

corresponding END-...statement.

Thus, it becomes immediately clear, which loop/logical constructs ends

where.

LOOP and DO/DOEND statements cannot be used.

Syntax Related to Closing Loops and Functional Blocks


12/34

Closing a Processing Loop in Reporting Mode

The statements END, LOOP (or CLOSE LOOP) or SORT may be used to close a

processing loop

The LOOP statement can be used to close more than one loop, and the END

statement can be used to close all active loops

A SORT statement closes all processing loops and initiates another processing loop

Closing a Processing Loop in Structured Mode

Structured mode uses a specific loop-closing statement for each processing loop.

Also, the END statement does not close any processing loop

The SORT statement must be preceded by an END-ALL statement and the SORT

loop must be closed with an END-SORT statement


13/34

Location of Data Elements in a Program

In reporting mode, you can use database fields without having to definethem in a DEFINE DATA statement

Also, you can define user-defined variables anywhere in a program, which

means that they can be scattered all over the program

In structured mode, alldata elements to be used have to be defined inone central location (either in the DEFINE DATA statement at the beginning

of the program, or in a data area outside the program)


14/34


15/34

NATURAL OBJECTS


16/34

OBJECTS OF NATURAL Objects are used to achieve efficient application structure

Types of objects :

Program

Subprogram

Subroutine

Copycode

Map

Local data area

Global Data Area

Parameter Data Area


17/34

Creating and Maintaining Objects

To create and maintain all these objects, you use the Natural editors

Local data areas, global data areas and parameter data areas arecreated/maintained with the data area editor

Maps are created/maintained with the map editor

All other types of objects listed are created/maintained with the program

editor


18/34

DATA AREAS


19/34

Natural supports three types of data area:

Local Data Area

Global Data Area

Parameter Data Area


20/34

Local Data Area

Variables defined as local are used only within a single Natural programming object

There are two options for defining local data:

You can define local data within a program

You can define local data outside a program in a separate Natural programming object

Example 1 - Fields Defined Directly within a DEFINE DATA Statement:

DEFINE DATA LOCAL

1 VIEWEMP VIEW OF EMPLOYEES

2 NAME

2 FIRST-NAME

2 PERSONNEL-ID

1 #VARI-A (A20)

1 #VARI-B (N3.2)

1 #VARI-C (I4)END-DEFINE

...


21/34

Example 2 - Fields Defined in a Separate Data Area:

Program:

DEFINE DATA LOCAL

USING LDA39

END-DEFINE

...

Local Data Area "LDA39":

I T L Name F Length MiscellaneousAll -- -------------------------------- - ---------- ------------------------->

V 1 VIEWEMP EMPLOYEES

2 PERSONNEL-ID A 8

2 FIRST-NAME A 20

2 NAME A 20

1 #VARI-A A 201 #VARI-B N 3.2

1 #VARI-C I 4


22/34

Global Data Area

A global data area (GDA) is a Natural programming object that allows programs

and external subroutines to share data elements

The data elements shared can be read or modified

In a GDA, you define the characteristics and the sequence of data elements thatdetermine the layout of a GDA instance

A GDA instance is a piece of storage containing data element values that can be

shared by Natural programming objects

Any modification of a data element value in a GDA affects all Naturalprogramming objects that reference the same instance of this GDA


23/34

Parameter Data Area

A Natural programming object of the type parameter data area (PDA) is used to

define the data elements that are passed as parameters to a subprogram or

external subroutine.

A PDA allows subprograms and external subroutines to use the same data element

definitions.

Subprogram is invoked with a CALLNAT statement. With the CALLNAT statement,parameters can be passed from the invoking object to the subprogram.

These parameters must be defined with a DEFINE DATA PARAMETER statement in

the subprogram

They can be defined in the PARAMETER clause of the DEFINE DATA statementitself; or

They can be defined in a separate parameter data area, with the DEFINE DATA

PARAMETER statement referencing that PDA.


24/34

Parameters Defined within DEFINE DATA PARAMETER Statement


25/34

Parameters Defined in Parameter Data Area


26/34

DEFINING DATA


27/34

DEFINING USER VARIABLES User-defined variable can be defined by specifying the following in the DEFINE DATA

statement

DEFINE DATA LOCAL

level-number variable-name (format/length)level-number variable-name (format/length)

level-number variable-name (format/length)

END-DEFINE

LEVEL-NUMBER => 1 or 2 digit numbers of range 01 to 99 (leading 0 optional)

VARIABLE-NAME => Should be alphanumeric format with length of 32 characters

Note: Working variables usually have # as first char


28/34

Level Numbers

The level numbering in view definitions, redefinitions and groups must besequential; no level numbers may be skipped

If you define a view, the specification of the view name must be on Level 1 andthe fields the view is comprised of must be on Level 2

Example of Level Numbers in View Definition:

DEFINE DATA LOCAL

1 VIEWEMP VIEW OF EMPLOYEES

2 NAME

2 FIRST-NAME

2 BIRTH

...

END-DEFINE


29/34

While redefining a field, the REDEFINE option must be on the same level as the originalfield and the fields resulting from the redefinition must be one level lower

Example of Level Numbers in Redefinition:

DEFINE DATA LOCAL

1 VIEWEMP VIEW OF STAFFDDM

2 BIRTH2 REDEFINE BIRTH3 #YEAR-OF-BIRTH (N4)3 #MONTH-OF-BIRTH (N2)3 #DAY-OF-BIRTH (N2)

1 #FIELDA (A20)

1 REDEFINE #FIELDA2 #SUBFIELD1 (N5)2 #SUBFIELD2 (A10)2 #SUBFIELD3 (N5)

...

END-DEFINE


30/34

Format/length of VARIABLE TYPES Alphanumeric (Annn) - 1 to 253 characters

Numeric (Nnn.m) - 1 to 29 digits

Integer (In) - 1,2 or 4 bytes

Date (D) - 4 bytes

Time (T) - 7 bytes

Logical (L) - 1 byte (TRUE/FALSE)

PACKED NUMERIC (P) - 1 TO 29 DIGITS

EXAMPLE :

DEFINE DATA LOCAL 01 #ENDOFFILE (L)

01 #DATEOFJOIN (D)

01 #EMPL-NAME (A20)

01 #EMP-SAL (N9.2) 01 #WS-COUNTER (I2)

END-DEFINE


31/34

INIT AT DEFINING

Initial value can be set while defining a variable

Example :

DEFINE DATA LOCAL01 #FIELD1 (N3) INIT 01 #FIELD2 (A10) INIT 01 #FIELD3 (L) INIT

END-DEFINE


32/34

REDEFINE The redefinition must be specified immediately after the definition of the

original field

In the following example #VAR2 is redefined as #VAR3

DEFINE DATA LOCAL

01 #VAR1 (A15)

01 #VAR202 #VAR22 (N4)

01 REDEFINE #VAR2

02 #VAR3 (A4)

END-DEFINE


33/34

FILLER FILLER can be used as in COBOL

1 #OUT-DETAIL-LINE (A100) INIT

1 REDEFINE #OUT-DETAIL-LINE

2 #OUT-MAILB-ID (A8)

2 FILLER 2X

2 #OUT-USER-IDEN (A25)

2 FILLER 2X

2 #OUT-DATE-ADDED (A10)

2 FILLER 2X

2 #OUT-TIME-ADDED (A8)2 FILLER 2X

2 #OUT-STATUS (A10)

2 FILLER 4X

2 #OUT-BTCH-NUM (N7)


34/34

Natural Part1

Documents

Transcript of Natural Part1