Using Externally Described WORKSTN Files

In

addition to the

field

descriptions (such as field names and attri

for

a display-device

file

are used to:

¹Format the placement of the record on the screen by specifying th

number and position-number entries for each field and constant.

¹Specify attention functions such as underlining and highlighting fields,

image, or a blinking cursor.

¹Specify validity checking for data entered at the display work sta checking functions include detecting fields where data is required, mandatory fill fields, detecting incorrect data types, detecting da range, checking data for a valid entry, and processing modules 10 o digit verification.

¹Control screen management functions, such as determining if fields are

erased, overlaid, or kept when new data is displayed.

¹Associate indicators 01 through 99 with command attention keys or comma

function keys. If a function

key

is

described

as

a command

functi

both

the

response indicator and

the

data

record (with any

modific

on the screen) are returned

to the program. If a

function

key

is

command

attention key (CA), the

response indicator

is

returned

to

the

but the data record remains

unmodified.

Therefore,

input-only

charac

are blank and input-only numeric

field

are

filled

with

zeros,

unless

have been

initialized otherwise.

 

 

 

 

 

 

 

¹Assign an edit code (EDTCDE) or edit word (EDTWRD) keyword to a fie

specify how the field’s values are to be displayed.

¹Specify subfiles.

A display-device-record format contains three types of fields:

¹Input fields. Input fields are passed from the device to the program

program

reads

a

record.

Input fields can be initialized with

a d

the

default

value

is

not

changed,

the default

value

is

passed

to

Input

 

fields

 

that

are not initialized are displayed as blanks

into

station

user

can

enter

data.

 

 

 

 

 

 

 

¹ Output

fields. Output

 

fields

are passed

from

the

program

to

the

devi

the

program

writes

a record to a display. Output fields can

be

program

or by

the

record

format

in

the

device

file.

 

 

¹Output/input (both). fieldsAn output/input field is an output field that ca changed. It becomes an input field if it is changed. Output/input

passed

from

the program when the program writes a

record

to

a di

passed

to

the program when the program reads a record from the d

Output/input

fields

are used when the user is to

change

or

update

is written

to the

display from the program.

 

 

 

If you specify the keyword INDARA in the DDS for a WORKSTN file, th program passes indicators to the WORKSTN file in a separate indicator not in the input/output buffer.

For

a detailed description of an externally-described display-device f

of

valid DDS keywords, DDSsee Reftherence.

Figure 165 on page 333 shows an example of the DDS for a display-devic

332 ILE RPG for AS/400 Programmer's Guide

Page 355 Page 357
Page 356
Image 356
IBM AS/400 manual ¹ Output, On page 333 shows an example of the DDS for a display-devic
Page 355 Page 357

AS/400 specifications

The IBM AS/400, now known as the IBM iSeries, is a midrange computer system that has been a cornerstone of enterprise computing since its introduction in 1988. Designed to provide a robust platform for business applications, the AS/400 is celebrated for its reliability, scalability, and integrated database capabilities.

One of the key features of the AS/400 is its Integrated Operating Environment, which blends hardware and software resources seamlessly. This integration allows businesses to execute diverse workloads, ranging from traditional applications to modern web-based services, all on a single platform. The operating system, OS/400 (now IBM i), offers a rich set of APIs and tools for developers, simplifying application development and management.

Another standout characteristic of the AS/400 is its built-in database, DB2 for i. This powerful relational database management system allows for efficient data handling and provides advanced features such as support for SQL, XML, and JSON, making it easier for businesses to manage their data and integrate it with other systems. The database's tight integration with the operating system enables high performance and security.

In terms of scalability, the AS/400 can accommodate small businesses as well as large enterprises, with the ability to support hundreds of users simultaneously. Its architecture allows for easy upgrades in hardware, meaning that organizations can scale their systems without replacing the entire infrastructure.

Security is another critical attribute of the AS/400. With a sophisticated security model, it offers built-in user authentication, access control, encryption, and auditing capabilities to protect data and applications from unauthorized access.

The AS/400 also supports multiple programming languages, including RPG, COBOL, Java, and PHP, giving organizations the flexibility to choose the development tools that best fit their needs. This diversity helps maintain legacy applications while also developing new ones that leverage modern technologies.

Moreover, the platform supports both traditional green-screen interfaces and modern graphical user interfaces, allowing organizations to transition smoothly into contemporary user experience paradigms.

Overall, the IBM AS/400 stands out as a resilient, flexible, and secure computing platform that enables organizations to effectively manage their business operations, streamline processes, and adapt to changing market demands. Its unique combination of integrated features and capabilities ensures that it remains relevant in today's fast-paced technology landscape.
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