RPG Skills for the New Millennium

Transcription

1 RPG Skills for the New Millennium Re-skill the RPG Programmer ComCon 5, Oakton Court Ballybrack Co. Dublin Ireland Phone: tuohyp@comconadvisor.com Web: Paul Tuohy Paul Tuohy Paul Tuohy has worked in the development of IBM Midrange applications since the 70s. He has been IT manager for Kodak Ireland Ltd. and Technical Director of Precision Software Ltd. and is currently CEO of ComCon, a midrange consultancy company based in Dublin, Ireland. He has been teaching and lecturing since the mid- 80s. Paul is the author of "Re-engineering RPG Legacy Applications, The Programmers Guide to iseries Navigator and the self teach course iseries Navigator for Programmers. He writes regular articles for iseries 400 Experts Journal and Search400 and is one of the quoted industry experts in the IBM Redbook "Who knew you could do that with RPG IV?". He is also an award winning speaker who speaks regularly at US Common conferences and the renowned RPG World conferences. Copyright ComCon,

2 Agenda Skills for what? Why do you need to re-skill? What has changed? What Are The First Steps? 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, XML and Javascript. Which GUI? Decide on the New Interface - Windows Application or Browser? What is CGI and how do you use it? Java The times they are a changing... Java Websphere RPG IV ILE Webfacing HTML/CGI Copyright ComCon,

3 Premise (V4R5 and V5R1) You are not using Third Party Tools There are many Great third party tools out there. Maybe you should be using one of them!!!! All You Have is Websphere Development Toolset! Application Development Toolset (ADTS). Websphere Development Tools for iseries. - CODE (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. And on V5R2 Websphere Development Studio Client for iseries New packaging which replaces WDT/400 in V5R2 and later shipped versions of V5R1 The good news: Great new Java programming toolset, new web design tools, strategic "Eclipse" plug-in technology base The bad news: CODE functionality is not yet incorporated into Eclipse base Existing CODE tool is shipped with WDSC... HOWEVER... - It is NOT separately installable (you must install everything) until V5R3 - Help text integration is not nearly as good as in existing (V5R1) CODE tool The moral is: If you are on V5R2 and you ONLY want CODE tools, don't lose the V5R1 WDT/400 CD set!!! Copyright ComCon,

4 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 (was Operations Navigator) - Especially the database. Grasp the basics of SQL (especially DDL) - You can do this from iseries Navigator without Interactive SQL. - SQL is slowly(?) replacing DDS. Find out about triggers. Find out about referential integrity. File Systems The Integrated File System Copyright ComCon,

5 SQL Get to grips with SQL especially Data Definition Language (DDL). It is becoming the standard for maintaining the database. SQL is being developed - DDS is not. iseries Navigator - Create a Table Copyright ComCon,

6 iseries Navigator - Create a View iseries Navigator - Database Navigator Copyright ComCon,

7 Triggers A Trigger is a program that is called whenever a specified record event occurs on a physical file. The Trigger Program is "called" by the DBMS, not by coding logic in your application. External Triggers and SQL Triggers allowed DB2/400 UPDATE PRODUCT PRODUCT STOCK MOVEMENT Referential Integrity The ability of the database management system to ensure: logical consistency of data values between files validity of data relationships validity of column contents robust enforcement of integrity constraints Delete request Delete denied Parent file Category File DB2/400 Constraints Product File Dependent file Enforce constraint Copyright ComCon,

8 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. The Right Tools Get with the right tools. SEU/SDA/RLU are NOT up to the job. Use of CODE/WDSCi can increase productivity by 20% to 40%!!! Copyright ComCon,

9 CODE CODE is A customizable editor Reference manual as help Navigator Verifier Much, much more CODE Editor Copyright ComCon,

10 CODE Verifier CODE Help Copyright ComCon,

11 CODE Navigator Code Designer Copyright ComCon,

12 WDSC RPG IV Highlights (1/2) 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. 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. Copyright ComCon,

13 RPG IV Highlights (2/2) 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 Sub Procedures and other ILE related features. Integration with Java. And, of course, free format. But perhaps the most important change with RPG IV is that the restructuring has made RPG even easier to change in the future. The Multiple Faces of RPG IV CL0N01Factor Opcode(E)+Factor Result Len++D+.. C HRS IFLE 40 C HRS MULT(H) RATE PAY 7 2 C ELSE C RATE MULT 40 REGPAY 7 2 C HRS SUB 40 HRSOT 3 0 C RATE MULT 1.5 OTRATE 3 2 C HRSOT MULT(H) OTRATE OTPAY 7 2 C REGPAY ADD OTPAY PAY 7 2 C ENDIF CL0N01Factor Opcode(E)Extended-factor C If (Hours <= 40) C Eval(H) WeeklyPay = Rate * Hours C Else C Eval(H) WeeklyPay = ((Hours-40) * (Rate*1.5)) C + (Rate * 40) C EndIf If (Hours <= 40); Eval(H) WeeklyPay = Rate * Hours; Else; Eval(H) WeeklyPay = ((Hours - 40) * (Rate * 1.5)) + (Rate * 40); EndIf; Copyright ComCon,

14 Subprocedures Subprocedures are the biggest change to RPG - EVER! They provide a means of encapsulation. A great replacement for subroutines - Can accept parameters (like a program) - Can contain local variables - Can be called recursively Subprocedures are do it yourself Built-In Functions - Can return a value - Can be used in expressions - Can be placed in Service Programs DayNumber = DayofWeek(InputDate); ErrInds = ValidCustomer(CustomerData); If (GetCustomerDept(Customer)) = 'A01'; Subprocedures This is what the code looks like... P DayOfWeek B Begin Procedure D PI 1P 0 D InpDate D Procedure Interface D ASaturday S D Inz(D'02/13/99') D WorkDay S 1P 0 Local variables /Free WorkDay = %Rem(%Diff(InpDate : ASaturday : *D): 7); If WorkDay < 1; WorkDay = WorkDay + 7; EndIf; Return WorkDay; Return Value /End-FREE P DayOfWeek E End Procedure Copyright ComCon,

15 ILE Subprocedures lead to Service Programs. You start to look at program design in a different way. Check the ILE Concepts manual Procedure Procedure Procedure Procedure *Module *Pgm Procedure Procedure *Module Procedure *Module Procedure Procedure Procedure *Module *SrvPgm 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!!!! Copyright ComCon,

16 VisualAge for RPG You need to learn GUI Design Event Driven But it is still RPG. C DispText BegAct MenuSelect CalTest C 'calendar' GetAtr 'SHOWTEXT' ultemp C Eval ultemp = 1 - ultemp C 'calendar' SetAtr ultemp 'SHOWTEXT' C Exsr updatembar C EndAct 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 CODE/WDSC is a HTML editor <html> <!-- Standard Work With Maintenance --> <head> <title>work With Products</title> <link rel="stylesheet" type = "text/css href="/cgiseminar/stylesheet.css"> </head> <body> <center> <h1>rpg Meets the Web!</h1> <h2>work With Products</h2> </center> Copyright ComCon,

17 Common Gateway Interface (CGI) What is CGI? A standard (APIs) for communicating between a browser, an HTTP Server and a script program (RPG IV in this case) The program generates HTML and passes it to the server - Which then sends it out for display as it would any other page The API's 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 HTML externally defined (like DDS) That way only the variable content is handled by the program - But writing a generalized routine to perform text substitution is not trivial IBM has an answer and it is FREE!! CGIDEV2 is available for download at www-922.ibm.com Sample of a CGI Web Page Copyright ComCon,

18 HTML for CGIDEV2 With CGIDEV2, the HTML is kept separate from (or external to) the RPG Program Identify sections or formats - /$TableRow Identify variables - /%ProdCd%/, /%CatCod%/ etc. : : /$TableRow <TR ALIGN=RIGHT> <TD>/%ProdCd%/</TD> <TD ALIGN=LEFT>/%ProdDs%/</TD> <TD><img border=0 src="/cgiseminar/images/p/%prodcd%/.jpg"></td> <TD>/%CatCod%/</TD> <TD>/%LndCst%/</TD> <TD>/%SellPr%/</TD> <TD>/%PrlOrdA%/</TD> <TD>/%NoDaysA%/</TD> </TR> : : Code Using CGIDEV2 Coding is So Much easier with CGIDEV2! // 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'); Copyright ComCon,

19 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!!!!! XML Learn the basics of XML Easy to learn, especially if you are familiar with HTML Lots of good books I liked XML for the World Wide Web" by Elizabeth Castro ISBN WDSC is an XML editor. <?xml version='1.0'?> <Products> <Product> <Code> </Code> <Description>Left Handed Spanner</Description> </Product> <Product> <Code> </Code> <Description>Philips Screwdrivers</Description> </Product> </Products> Copyright ComCon,

20 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> Webfacing Time:8:05 date:oct 22,2000 Write Header; Write MsgSflC; ExFmt Detail; ErrInds = *Zeros; ClrErrMsg(); PositionCursor = *Off; Select; RPG Program When FrcExt = 'Y'; #Ctl = '*END'; When F3Exit; #Ctl = '*END'; #Retrn = 'X'; When F4Prompt; #Ctl = 'F4PM'; When F12Cancel; #Ctl = '*END'; Workstation manager 5250 Web 5250 to Web conversion enter Product number: Converts DDS to Servlets and JSPs There is NO change to the RPG Programs Copyright ComCon,

21 WDSC for Web Design Websphere Application Server Servlets Java Server Pages (JSPs) Enterprise Java Beans (EJBs) Web Browser HTML Application Server Any Client, Any Browser EJB Client TCP /IP HTTP server Servlet Engine EJB Container JDBC RPG Cobo Etc.l Data base Admin Console Administrative Server Copyright ComCon,

22 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 Address Java Java is an OO Language Copyright ComCon,

23 Java Code in CODE Java Code in WDSC Copyright ComCon,

24 A Plan of Action Must Do... Should Do... And then Any of... IFS iseries Navigator SQL Triggers and RI WDSC/CODE RPG IV and ILE HTML CGI XML Javascript WebFacing VisualAge for RPG OO and Java Websphere Application Server, JSPs, etc. The Learning Curve Times are opinion based on the experience of many. "Practice" is to a level of proficiency as opposed to expertise. +-& &'.*! +,!!"#!$%! &' #% $. #/%+!-!0! (( )* Copyright ComCon,

25 How Long Will It Take? Pick the Route Carefully!!!!!! Course Self Teach Practice Code/ RPG IV ILE Basic CGI CGIDEV Basic WAS Webfacing WDSC for Web OO Java Course/Practice = Self Teach/Practice = 394 The Choice is Yours! Lay the foundations IFS, SQL, iseries Navigator, Triggers, Referential Integrity, RPG IV and ILE. Take the first step CODE/WDSC HTML CGI XML Jump VisualAge for RPG Webfacing OO and Java Copyright ComCon,

26 Some References (1 of 2) iseries Navigator for Programmers Self teach course by Paul Tuohy at "Who Knew You Could Do That With RPG IV". IBM Red Book SG at ILE Concepts Manual Information Center "Re-Engineering RPG Legacy Applications" By Paul Tuohy ISBN at mc-store.com "HTML for the World Wide Web" By Elizabeth Castro ISBN XML for the World Wide Web" By Elizabeth Castro ISBN SQL/400 Developer's Guide by Paul Conte and Mike Cravitz ISBN at Some References (2 of 2) The CGIDEV2 web site www-922.ibm.com "e-rpg - Building AS/400 Web Applications with RPG" By Brad Stone ISBN at mc-store.com "Java for RPG Programmers" By George Farr and Phil Coulthard ISBN at mcstore.com Copyright ComCon,