Transcript RPG IV - TechTarget

Skills for the RPG Programmer
Re-skilling the RPG Programmer
Paul Tuohy
ComCon
5, Oakton Court
Ballybrack
Co. Dublin
Ireland
Phone: +353 1 282 6230
e-Mail: [email protected]
Web: www.ComConAdvisor.com
© 2001 ComCon
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Skills for the RPG Programmer
Re-skilling the RPG Programmer
Paul Tuohy
ComCon
5, Oakton Court
Ballybrack
Co. Dublin
Ireland
Phone: +353 1 282 6230
e-Mail: [email protected]
Web: www.ComConAdvisor.com
© 2001 ComCon
Agenda
Skills for what?
Why do you need to re-skill?
 What has changed?

What Are The First Steps?
Know your system.
 Know your database.
 Use The Right Tools for the Job.
 Get to Grips with RPG IV and ILE.
 Find Out about Event-Driven Programming.
 Learn the basics of HTML and Javascript.

Then What?
HTML, Javascript and CGI.
 Visualage RPG
 Java
 WebSphere whatever.

© 2001 ComCon
The times they are a changing.......
Java
WebSphere
ILE
RPG IV
WebFacing
HTML/CGI
© 2001 ComCon
Premise
You are not using third-party tools
There are many Great third-party tools out there.
 I will mention some later.
 Maybe you should be using one of them!!!!

All You Have is WebSphere Development Toolset (V5R1)
or WebSphere Development Studio Client (V5R1/V5R2)!
Application Development Toolset (ADTS).
 WebSphere Development Tools for iSeries.

–Code/400
(Editor, Designer, Project Manager).
–Distributed Debugger
– WebSphere Studio
– WebFacing Tool
–VisualAge for RPG.
VisualAge for Java
 ALL of the compilers for OS/400

–RPG,
Cobol, C, Java, etc.
© 2001 ComCon
Where to Start?
There are a few things you need to look into before you enhance
your programming skills.
Become familiar with the IFS (Integrated File System)
 Become familiar with iSeries Navigator (Operations Navigator)

–Especially

the IFS and Database.
Grasp the basics of SQL
–You
can do this from iSeries Navigator without Interactive SQL.
–SQL is slowly(?) replacing DDS.
Find out about triggers.
 Find out about referential integrity.

© 2001 ComCon
Use iSeries Navigator
iSeries Navigator is the GUI interface for OS/400
Navigator is getting the development dollars – Green Screen is not!
 Navigator is part of the “free” portion of iSeries Access.
 Have a look at Basic Operations to get a feel for how it works.
 Become familiar with the IFS (Integrated File System)
 Become familiar with the Databases.

© 2001 ComCon
Explore the IFS
iSeries supports multiple file systems – not just QSYS!
Root
- PC style
 QOpenSys
- Unix style
 QDLS
- Shared Folders
 QSYS.LIB
- Traditional OS/400
 QOPT
- Optical Storage
 QNTC
- Windows NT Servers
 And more……

© 2001 ComCon
Explore Databases
This is the new interface for Database functions

Have a look at how tables/views and indexes are created
© 2001 ComCon
Creating a Table
This is not DDS!

Navigator offers a “friendly” interface to SQL’s Data Definition Language (DDL)
© 2001 ComCon
Database Navigator
Database Navigator will give you a diagram of your Database!

Just a little bit easier then DSPFD and DSPFFD!
© 2001 ComCon
SQL
Get to grips with SQL.
It is becoming the standard for maintaining the database.
 SQL is being developed - DDS is not.

© 2001 ComCon
Triggers and Referential Integrity
Triggers
Programs that are called when a row (record) is inserted, updated or deleted.
 An excellent means of applying business rules.

Referential Integrity

Define relationships between tables (physical files) e.g.
You cannot delete a customer if they have outstanding invoices
When you delete the Order Header record, automatically delete all
corresponding Order Details.
© 2001 ComCon
The Choices
Green Screen
Although everything is heading towards GUI,
there is still a place for green screen within
applications.
 Not everything lends itself to point and click.

GUI Application

Good old Client Server!
Browser-based
The interface is in a browser.
 Fast becoming the most popular.
 Easiest to distribute to the Internet.

© 2001 ComCon
The Right Tools
Get with the right tools.
SEU/SDA/RLU are NOT up to the job.
Use of Code/400 can increase productivity by 20% to 40%!!!
© 2001 ComCon
Code/400
Code/400 is
A customizable editor
 Reference manual as help
 Navigator
 Verifier
 Much, much more

© 2001 ComCon
Code/400 Editor
© 2001 ComCon
Code/400 Verifier
© 2001 ComCon
Code/400 Help
© 2001 ComCon
Code/400 Navigator
© 2001 ComCon
RPG IV
Get up to speed with RPG IV
If you are still using RPG III - STOP NOW
You will start to see gains from RPG IV within a very short period of
time.
/FREE
D_PgmTxt = *Blank;
D_Proc = SDSProcName;
D_PgmTxt = 'Work with';
If Show_Paid and Show_Unpaid;
D_PgmTxt = %trim(D_PgmTxt) + ' Paid and Unpaid';
EndIf;
If Show_Paid and Not Show_Unpaid;
D_PgmTxt = %trim(D_PgmTxt) + ' Paid';
EndIf;
/END-FREE
© 2001 ComCon
Getting there……
Getting there is easy!
CVTRPGSRC
IBM supplied conversion tool.
 Performs basic syntax conversion.
 Convert, Compile, Relax.

Third-party Option
If you want more than basic syntax conversion.
 If you want code re-engineered to use new features.
 Check out the RPGToolBox from Linoma Software (www.linoma.com)

© 2001 ComCon
RPG IV Highlights
Here you have it -- the brand new RPG!
10-character external names (files, format and field names).
 Allow mixed case.
 Allow blank lines.
 Introduction of new Definition (D) Specification.
 Elimination of Extension (E) and Line Counter (L) Specifications and the
practical elimination of Input (I) Specifications.
 Re-definition of the Header (H), File (F) and Calculation (C) Specifications.
 More powerful array definition and processing.
 Prefixing externally defined files.
 Date processing and manipulation.
 Named Indicators

Introduction of new data types, especially integers and pointers.
 Introduction of Built-in Functions (e.g. %SUBST).
 Introduction of Subprocedures and other ILE-related features.
 Integration with Java.
 And, of course, free format.
 But perhaps the most important change is that the re-structuring has made RPG
even easier to change in the future

© 2001 ComCon
Subprocedures
Subprocedures are the biggest change to RPG - EVER!
They provide a means of encapsulation.
DayNumber = DayofWeek(InputDate);
ErrInds = ValidCustomer(CustomerData);
If (GetCustomerDept(Customer)) = 'A01';
© 2001 ComCon
Subprocedures
This is what the code looks like.......
P DayOfWeek
D
D InpDate
B
PI
D ASaturday
D WorkDay
S
S
1P 0
D
D
Inz(D'02/13/99')
1P 0
/FREE
WorkDay = %Rem(%Diff(InpDate : ASaturday : *D): 7);
If WorkDay < 1;
WorkDay = WorkDay + 7;
EndIf;
Return WorkDay;
/END-FREE
P DayOfWeek
E
© 2001 ComCon
ILE
Subprocedures lead to Service Programs.
You start to look at program design in a different way.
Procedure
Procedure
Procedure
*Module
Procedure
Procedure
Procedure
Procedure
*Module
*Module
Procedure
Procedure
Procedure
*Pgm
*Module
*SrvPgm
© 2001 ComCon
Clients are Event Driven!
Client Applications are event driven.
Client Applications can be written in:
Java
 Visual Basic
 C/C++
 Any PC programming language
 Even RPG!!!!

For VisualAge RPG you need to learn
GUI Design
 Event Driven
 But it is still RPG

© 2001 ComCon
HTML
Learn the basics of HTML
Easy to learn
 Lots of good books.
 I liked "HTML for the World Wide Web" by
Elizabeth Castro ISBN 0-201-35493-4
 Code/400 is a HTML editor.

<TR><td ALIGN=CENTER VALIGN=TOP
WIDTH="404" HEIGHT="186"><font face="Arial">To contact us:
<p>Phone: +353 1 282 6230<br>
Fax: +353 1 282 6230<br>
Email:<a href="mailto:[email protected]">
[email protected]</a>
<p>5, Oakton Court<br>
Ballybrack<br>
Co. Dublin<br>
Ireland
<p>&copy; ComCon Computer Consultants 2002</font>
</td></TR>
© 2001 ComCon
What is CGI ?
CGI stands for 'Common Gateway Interface'

It supports the ability to dynamically build Web pages
–It

dictates format of the data stream for requests and responses
A standard for communicating between a browser and an HTTP Server
Server is configured to pass specific URLs to CGI scripts
Not simply to respond with a pre-built Web page
 In our case the "script" will be an RPG IV program

The program generates HTML and passes it to the server

Which then sends it out for display as it would any other page
CGI programming on the AS/400 is supported by
RPG IV (ILE RPG)
 Java

–
Plus ILE COBOL, ILE C, ILE C++, Rexx and Perl
© 2001 ComCon
Sample of a CGI Web Page
© 2001 ComCon
Sample of Code for Previous Page
This writes one "detail" line

The HTML code is constructed in
the RPG Program.
WebOut = NewLine
+ '<tr align=right>'
+ '<td>' + ProdCd +'</td>'
+ '<td align=left>'
+ ProdDs +'</td>'
+ '<td>' + CatCod + '</td>'
+ '<td>' + %Char(LndCst) + '</td>'
+ '<td>' + %Char(SellPr) + '</td>'
+ '<td>' + PrLOrdA + '</td>'
+ '<td>' + NoDaysA +'</td></tr>'
WriteWebData(WebData : WebDataLen : APIError)
© 2001 ComCon
"Native" CGI problems
The APIs are not as simple as one would like

And the documentation is less than wonderful
Generating HTML directly in the program reduces flexibility

To change the text, one must change the program
–And
it is much more difficult to use HTML editors to design the pages
It would be nice to have something like DDS

That way only the variable content is handled by the program
–But
writing such a generalized routine to process HTML text and perform text
substitution is not a trivial task
IBM has an answer

And it is FREE !!
The CGIDEV2 Library

Available for download at www-922.ibm.com
© 2001 ComCon
Sample from CGIDEV
WIth CGIDEV, the HTML is kept
separate from (or external to) the
RPG Program.
:
:
/$TableRow
<TR ALIGN=RIGHT>
<TD /%ProdCd%/</TD>
<TD ALIGN=LEFT>/%ProdDs%/</TD>
<TD>/%CatCod%/</TD>
<TD>/%LndCst%/</TD>
<TD>/%SellPr%/</TD>
<TD>/%PrlOrdA%/</TD>
<TD>/%NoDaysA%/</TD>
</TR>
:
:
© 2001 ComCon
Code from Previous Sample
Coding is MUCH easier with
CGIDEV
// Load substitution variables
UpdHTMLVar('ProdCd':ProdCd)
UpdHTMLVar('ProdDs':ProdDs)
UpdHTMLVar('CatCod':CatCod)
UpdHTMLVar('LndCst':%Char(LndCst))
UpdHTMLVar('SellPr':%Char(SellPr))
UpdHTMLVar('PrlOrdA':PrlOrdA)
UpdHTMLVar('NoDaysA':NoDaysA)
// And add row to table
WrtSection('TableRow')
© 2001 ComCon
So Far......
If you learn
RPG IV
 Some ILE
 Some HTML

You can be on the Web in No Time!
Getting to the Web is Easy!!!!!
© 2001 ComCon
Javascript
Extend those HTML capabilities
Javascript is NOT full blown Java by any means.
<HTML><HEAD><TITLE>Quote of the Day</TITLE>
</HEAD><BODY><DIV ALIGN=CENTER><H1>Quote of the Day</H1>
<HR><FONT COLOR="navy" SIZE="5">
<SCRIPT>
<!-var quotes = new Array()
quotes[0] = "Every time history repeats itself the price goes...
quotes[1] = "The moment you think you understand a great work ...
..
..
..
..
quotes[9] = "So little done, so much to do....
document.write(quotes[Math.round(Math.random()*9)])
// -->
</SCRIPT></FONT></DIV></BODY></HTML>
© 2001 ComCon
WebFacing
Time:8:05
date:Oct 22,2000
enter customer number:_____
RPG Program
DOWProto
P DayOfWeek
B
D
PI D/Copy 1P0
D WorkDate
D
D AnySunday
S
D WorkNum
D WorkDay
S
S
D INZ(D'1995-04-02')
7 0
1P 0
C WorkDate
SubDur AnySunday WorkNum:*D
C WorkNum
Div
7
WorkNum
C
MvR
WorkDay
C
If
WorkDay < 1
C
Return WorkDay + 7
C
Else
C
Return WorkDay
C
EndIf
P DayOfWeek
E
Workstation
manager
?
Converts DDS to Servlets and JSPs
There is NO change to the RPG Programs
© 2001 ComCon
WebSphere Studio
© 2001 ComCon
WebSphere Application Server
Servlets
 Java Server Pages (JSPs)
 Enterprise Java Beans (EJBs)

Web
Browser
HTML
Application Server
HTTP
server
Any Client,
Any Browser
Servlet Engine
EJB Client
TCP
/IP
Admin
Console
EJB Container
Administrative
Server
© 2001 ComCon
JDBC
RPG
Cobol
Etc.
Data
base
And then there is Java
Get to grips with OO.... it is very different.
A good grounding in RPG IV and ILE makes it easier to understand.
Set Name
& Address
Set
Balance
Set
Balance
Get
Balance
Get Phone
Get Address
Set Balance
Get Balance
Get
Address
A Customer
© 2001 ComCon
Get Name
Java
Java is an OO language
© 2001 ComCon
Java Code in Code/400
© 2001 ComCon
A Plan of Action
Must Do.......
Should Do.......
IFS
Code/400
iSeries
Navigator
SQL
RPG IV and
ILE
HTML and
CGI
And then Any of.......
WebFacing
VisualAge for
RPG
OO and Java
WebSphere
Studio,
Javascript
and JSPs
Triggers and
RI
© 2001 ComCon
The Learning Curve
Times are opinion based on the experience of many.
 "Practice" is to a level of proficiency as opposed to expertise.

T he Learning Curve
Code/400
RPG IV
ILE
Basic CGI
CGIDEV
T opics
Course
Self T each
Basic W AS
Practice
Basic W ebfacing
W ebsphere Studio
OO
Java
0
10
20
30
40
50
W ork Days
© 2001 ComCon
60
70
80
90
100
How Long Will It Take?
Pick the Route Carefully!!!!!!
Course
Code/400
RPG IV
ILE
Basic CGI
CGIDEV
Basic WAS
Webfacing
Studio
OO
Java
Self Teach
Practice
2
5
7
4
2
1
2
3
2
2
3
8
10
10
5
5
10
5
5
10
20
10
80
25
15
20
15
10
100
30
© 2001 ComCon
The Choice is Yours!!
Lay the foundations

IFS, SQL, iSeries Navigator, Triggers, Referential Integrity.
Take the first step
Code/400
 RPG IV and ILE
 HTML
 CGI

Jump
VisualAge for RPG
 WebFacing
 OO and Java

© 2001 ComCon
Some References
"Who Knew You Could Do That With RPG IV?"

IBM Red Book SG24-5402 at www.redbooks.ibm.com
"Re-Engineering RPG Legacy Applications"

By Paul Tuohy ISBN 1-58347-006-9 at mc-store.com
"HTML for the World Wide Web"

By Elizabeth Castro ISBN 0-201-35493-4
"e-RPG - Building AS/400 Web Applications with RPG"

By Brad Stone ISBN 158347-008-5 at mc-store.com
"Java for RPG Programmers"

By George Farr and Phil Coulthard ISBN 1-889671-23-1 at mc-store.com
The CGIDEV2 web site

www-992.ibm.com
The RPG Toolbox

www.linoma.com
© 2001 ComCon
Questions?
Submit your questions now by clicking on the
“Ask A Question” button in the left corner
of your presentation screen.
Paul will answer your questions
shortly after the broadcast.