Transcript Document

IBM Software Group / DB2 Information Management
Informix 4GL and EGL
Jerry Keesee, Director of the Informix lab
S. Venkatesh Gopal, Development, Informix R&D
© 2005 IBM Corporation
IBM Software Group / DB2 Information
Management
Disclosure Information
 PLANS ARE SUBJECT TO CHANGE OR
CANCELLATION WITHOUT NOTICE
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© 2005 IBM Corporation
February 2, 2005
IBM Software Group / DB2 Information
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Agenda
 Informix 4GL Today
 Why EGL?
 Overview of some EGL capabilities
 4GL / EGL Syntax Comparison
 JSF & EGL – Web Application Development
Overview
 Conversion of 4GL to EGL
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Current I4GL Development/Runtime Environment
 A well established development environment.
 Can be deployed as either pseudo-code (P code)
or C code applications
– P code primarily is used for development – debugger works
with P code only
– most develop with P code and deploy with C code
 Connectivity to Informix database servers only
– unless an Informix Gateway server is added
 Small disk/memory footprint delivers very good
runtime performance
 Wide platform coverage.
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Primary Requirements for I4GL
 Provide application database connectivity to IDS & DB2
 Provide a modern integrated development environment
 Provide the capability to create modern applications with:
– graphical user interfaces
– and character-based user interfaces
 Maintain and grow user base
– enhancements should “fit” existing users
– and be compelling for new ones…
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EGL
 A language as easy as I4GL to use and develop with.
 Provides an industry standard IDE (Rational Application developer)
for developing EGL, Java, Web and COBOL applications.
 Provides an enriched set of the same capabilities.
– Text user interface (Curses based).
– Calls to “C” functions.
– SQL (embedded, dynamic and more).
– Interactive debugging capability.
– Powerful reporting capability.
– Command line based application development.
– Data types (all of I4GL and some more in addition).
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EGL .....
 In addition to the I4GL feature set provides
– Development and runtime capabilities for Windows platforms.
– More general programming capabilities.
– Web Application development and deployment.
• Same business logic can be shared in both deployments.
– Multiple Database connectivity.
• Uses JDBC and allows to connect to any DB.
–
–
–
–
Service Oriented Architecture (Web Services).
MQ Access.
File I/O
Provides for COBOL generation options (deployable in i-Series and zSeries).
– Calling out Java code from EGL.
– and more…
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EGL (similarities to I4GL).
 Lots of similarities.
– Basic statements and looping constructs are similar.
– SQL statements are similar to 4GL (prepare, execute,
open, get (fetch), close and for each).
– Text user interface similar (with a more general
programming model) to I4GL with extended capabilities.
– Reporting framework provides for a wider set of output
formats (PDF, Text, XML, CSV, HTML).
– A highly interactive and visual debugging environment
based on the Eclipse framework.
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Examples (Comparing I4GL to EGL).
DEFINE INTVAL INTEGER
INTVAL INT;
DEFINE myRecord RECORD
Record myRecordType
intval INTEGER,
intval int;
floatval FLOAT,
floatval float;
decimalval DECIMAL
decimalval decimal;
END RECORD
End
myRecord myRecordType;
myotherRecord myRecordType;
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LET intval = 10
intval = 10;
LET myrecord.intval = 10
myRecord.intval = 10;
CALL funcName(param1,param2)
funcName(param1,param2);
© 2005 IBM Corporation
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Examples (Comparing I4GL to EGL).
while(i < 10)
let i = i + 1
while(i < 10)
i = i+1;
end while
End
case (i)
case(i)
when 10
when (10)
…
when 20
…
when (20)
…
otherwise
…
otherwise
…
End case
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…
end
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Examples (SQL in I4GL compared to EGL)
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insert into mytable (code, quantity)
values (‘abc’, 10)
execute #sql{
prepare stmtid from "select
fname,lname from customer where
customer_num=10"
prepare stmtid from "select
fname,lname from customer where
customer_num=10";
declare secondSet cursor for select
fname,lname from customer
open secondSet
open secondSet
#sql{select fname,lname from
customer };
fetch secondset into fname,lname;
get next from secondSet into
fname,lname;
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insert into mytable(code,quantity)
values('abc',10)};
with
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Some Infrastructure differences…
 EGL being IDE based requires knowledge of
Eclipse Workspace paradigms.
 Everything exists in a workspace
– Workspace has projects.
• Projects have packages.
– Packages have files.
– Files can be either EGL source files, EGL programs or EGL libraries.
 A program is equivalent to a I4GL file having the
main function.
 A library is equivalent to any I4GL modules that
provides functions for use by other I4GL modules
or I4GL globals file.
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Informix 4GL Today
EGL Today
PACKAGE PlayerStatsApplication;
DATABASE stats
import InfxDbSchema.sports.stats.*;
GLOBALS
DEFINE player_bats RECORD LIKE informix.atbats.*
DEFINE batting_ave RECORD LIKE informix.battingaverage.*
END GLOBALS
-----------------------------------------MAIN
-----------------------------------------DEFINE BA DECIMAL (4,3)
DECLARE curs_at_bats cursor for select * from informix.atbats
OPEN curs_at_bats
WHILE (SQLCA.SQLCODE = 0)
FETCH curs_at_bats into player_bats.*
IF (SQLCA.SQLCODE = 100) THEN
EXIT WHILE
END IF
CALL compute_BA(player_bats.atbats, player_bats.hits) RETURNING BA
INSERT INTO informix.battingaverage VALUES (player_bats.lname, BA);
END WHILE
COMMIT WORK
CLOSE curs_at_bats
END MAIN
PROGRAM player_main
use player_ba;
player_bats rec_like_informix_atbats;
batting_ave rec_like_informix_battingaverage;
FUNCTION main()
BA DECIMAL (4,3);
PREPARE $_STMT_curs_at_bats FROM "select * from informix.atbats";
open curs_at_bats with $_STMT_curs_at_bats;
WHILE (SQLCODE = 0)
get next from curs_at_bats into player_bats.lname, player_bats.atbats,
player_bats.hits, player_bats.walks;
IF (SQLCODE = 100)
EXIT WHILE;
END
BA = compute_BA(player_bats.atbats, player_bats.hits);
execute #sql{INSERT INTO informix.battingaverage VALUES (:player_bats.lname, :BA) };
END //WHILE
commit() ;
CLOSE curs_at_bats;
END // FUNCTION
END // PROGRAM
FUNCTION compute_BA(at_bats, hits)
DEFINE at_bats INTEGER
DEFINE hits INTEGER
DEFINE BA DECIMAL (4,3)
LET BA = hits/at_bats
RETURN BA
END FUNCTION
PACKAGE PlayerStatsApplication;
LIBRARY player_ba
FUNCTION compute_BA(at_bats INT IN, hits INT IN) returns (DECIMAL (4,3))
IDS
BA DECIMAL (4,3);
BA = hits/at_bats;
RETURN( BA);
END // FUNCTION
END // LIBRARY
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Compiling and running applications.
 Set up the compilation options in the build
descriptor.
 Generate to Java
 Run the application.
 Take the generate Java and deploy it to any other
machine with the runtime libraries.
 If you have created a web application, deploy the
web archives to the test server or any J2EE server
from within the IDE.
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Some extended capabilities…
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Integrated development environment
 An industry standard IDE
 Based on the Eclipse framework
 Provides for different development perspectives
– EGL
– EGL/Web
– Java and more.
 Context Sensitive editor
 Debugging capability (Interpretive debugger).
 Page designer for JSPs and page handlers.
 Code Assist (using Ctrl + Space)
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Records
 Different types…
– Basic Records
– SQL Records
– Serial Records
– Indexed Records
– MQ Records.
 Record type identifies the I/O that can be done
 Same statements are used for different Record
types
 No I/O with Basic records.
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Records
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Operation
Serial
SQL
Indexed
MQ
add
insert record at end
of file
Insert record
insert record at key
send record to
queue
close
close file
close file
close file
close queue
delete
n/a
delete current
record
delete current
record
n/a
get (key)
n/a
record based on
key
record based on
key
n/a
get next
get next record
get next record
get next record
get next message
get previous
n/a
replace
n/a
© 2005 IBM Corporation
get previous record get previous record
replace current
record
replace current
record
February 2, 2005
n/a
n/a
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Records (SQL Records)
 Record definition
Record CustomerRecord type SQLRecord {tableNames=("customer") }
customer_num int {column=customer_num};
fname char(15) {column = fname};
lname char(15) {column = lname};
company char(20) {column = company};
address1 char(20) {column = address1};
address2 char(20) {column = address2};
city char(15) {column = city};
state char(2) {column = state};
zipcode char(5) {column = zipcode};
phone char(18) {column = phone};
end
 A default SQL statement is generated for every SQLRecord
 The SQL column information can be extracted using the IDE.
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SQL Records (example)
mycustomer CustomerRecord;
myCustomerArray customerRecord[];
open resultSet
for mycustomer;
try
while(sqlcode = 0)
get next from resultSet;
//mycustomer.customer_num has the value.
if(sqlcode = 100)
exit while;
end
end
onException
End
get myCustomerArray;
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File I/O using Records
 Create a serialRecord.
Record FileRecord type serialRecord {filename="customer"}
customer_num num(10);
fname char(15);
lname char(15);
End
 Create a Resource Association.
 Write your code.
myfilerecord FileRecord;
myfilerecord.customer_num = 100;
myfilerecord.fname = “John”;
myfilerecord.lname = “Doe”;
add myfilerecord;
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Message Queue Access
 Easy MQ handling.
– Create Record definitions.
Record myMQRecord type MQRecord { queueName = "mqRA" }
fname char(10);
lname char(10);
End
– Create a Resource Association between the queueName attribute and the MQ system.
– Write your code.
mqr myMQRecord;
mqr.fname="Venkatesh";
mqr.lname="Gopal";
add mqr;
get mqr;
– Take full advantage using a package called “MQReusableParts”, a part of your
standard distribution.
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Web Development with EGL.
Sun PetStore Reference Application:
Hand-Coded
in Java IDE
MDD Competitor
WebSphere Studio
JSF & EGL*
507.5 Hours
330 Hours
55 Hours
*Internal Study
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Web Development using JSF
 JSF is a J2EE Web UI / programming framework
 User interface component model - Set of standard
widgets
 Specification allows creation of custom UI
components
 Event handlers to process client-driven events
 Actions to call business logic
 Validation framework to allow server side
validation
 Internationalization/Localization
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How do JSF and EGL fit together?
Controller
JSF
Request
Model
EGL
Servlet
(Faces Servlet)
EGL
Invokes
Response
JSP
(View)
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EGL
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Management
How do JSF and EGL fit together?
 A perspective (EGL Web) that allows users to create a view (JSP)
containing standard controls and widgets.
 Easy Drag and Drop to bind the data components to presentation
items in the view.
 Automatic creation of a page handler that implements the controller
– Has an onPageLoad function, which is invoked the first time the web
page is rendered.
– A set of event handlers, each of which is invoked in response to a
specific user action (like clicking on a button or a link).
– Validation functions to validate web-page input fields.
 Page handler can call other EGL library functions that implement the
actual business logic.
 Data can be passed between pages using simple EGL statements.
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Taking your applications from 4GL to EGL
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What is the Conversion Strategy?
 Goal is to convert an I4GL application to the equivalent EGL application that
uses:
– the same display device
– the same database server
– I4GL TUI applications will be converted to EGL TUI applications
 Convert, on a program-by-program basis, using the conversion utilities:
– provided as part of the IDE
– also available from the command line
 Separate conversion passes required for:
– database metadata extraction
– shared libraries (C code or combination of C and I4GL code)
– I4GL source code
 Automated conversion should convert most 4GL source code
– but, some 4GL programs may require manual intervention
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Conversion Assumptions
 I4GL code is “legal”
– it will compile with I4GL 7.32 compiler
– conversion will not “fix” invalid I4GL code
 Multiple passes are required
 Functions that can not be resolved during
conversion are assumed to be C code functions
– if function is later found to be an I4GL function, re-conversion
would be required
 C code functions do not use undocumented I4GL
internal functions
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How is this Going to be Done?
 WebSphere Studio conversion plug-in
– runs within the EGL development environment (Windows or
Linux)
• I4GL source directories can be mounted from current environments
• or copied to the EGL development environment
– GUI wizard collects information about I4GL source environment:
•
•
•
•
I4GL source and EGL destination directories
I4GL source files (.4gl, .per, .c, .so, message files, etc)
database connection information
locale information
– generates configuration XML files
– invokes the conversion utility
• displays conversion log upon completion
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How is this Going to be Done?
 Command line conversion utility
– Java program can be run in current I4GL build environments
• perhaps via current makefiles
– requires XML configuration file describing current 4GL
environment:
• could be generated using the IDE plugin
• or generated via shell script
– generates EGL conversion “projects” containing
•
•
•
•
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database meta data
makefiles to re-link C code with new EGL stack library
EGL source files
report designs and other reporting artifacts
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Conversion Artifacts
 Configuration file
– XML file generated from interaction with conversion wizard
– contains required conversion project information
 Manifest file
– XML file generated during conversion of shared libraries
– contains declaration and usage information about each of the functions
(C and I4GL) used in the shared library
– used to resolve function declarations in dependent I4GL shared libraries
– required for subsequent I4GL source code conversions
 Log file
– contains warnings and errors
– status of each source file
– summary of conversion
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Order of Conversion is Important!
 Database metadata
– conversion creates EGL packages for each database used in the
project
– schema metadata will become a separate EGL project which
can be referenced by other EGL projects
 Shared libraries
– conversion generates Manifest file and makefile
 I4GL source files
– .4gl files
– .per (form) files
– message files
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Pre-Conversion Tasks
 Identify & locate all the components of the 4GL
application to be converted
– (.4gl, .per, message files, shared libraries)
 Identify connection information for each database
used
 Start Informix database instances
 Mount/copy source code to EGL development
machine, if required
 Determine destination directory for converted EGL
source code & conversion artifacts
 Identify “Client” locale – used to convert message
files
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Conversion Utility Processing
 Map all I4GL constructs into equivalent EGL constructs
 Convert existing “.4gl” source files into “.egl” source files
 Convert existing “.per” form specification files into “.egl” TUI specification files
– No special file extensions for EGL form definitions
 Migrate existing I4GL error message files into EGL error messages
 Convert existing I4GL reporting logic into equivalent EGL reporting logic
 Generate a “makefile” that will be used to link the C shared libraries to the
converted EGL project
– makefile will have targets for different operating systems
 Report all warnings and errors
 Generate log file to indicate the status of conversion
 Create default EGL build descriptor file for the project
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Conversion tool within the IDE….
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Conversion tool…
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Conversion tool….
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Conversion tool (artifacts)…
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Conversion tool (conversion log).
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Post-Conversion Tasks
 Review log file
 Fix identified problems
– on the 4GL side and re-convert or
– in the new EGL file
– shared libraries may have to be re-converted if functions cannot be
resolved
 Open the project in the IDE
 Verify EGL packages and source files
 View/update EGL build descriptor file
 “Generate” Java code for the project
– fix problems in the EGL code
 Set runtime properties from existing environment variables
 Launch new EGL project
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Conversion Limitations
 Database connections cannot be shared between
EGL and C code
 C code cannot call EGL functions
 Default values set in syscolval table are not
accessed
 I4GL Dynamic Arrays (7.32 release) will not be
converted in initial release
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Typical I4GL Program … Becomes Typical EGL Program
form.per
BL
BL
BL
main.4gl
C functions
BL
c_code.so
inventory.4gl
catalog.4gl
Text
IDS
Reports
I4GL to EGL Conversion
C functions
Text
Reports
SchemaLib.egl
BL
BL
main.egl
form.egl
BL
BL
inventory.egl
catalog.egl
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c_code.so
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Now What Can You Do With It …
Use your I4GL
Business
Logic in EGL
Web Services
Webmain.egl
Use your I4GL
Business Logic
in whatever
comes next!!!
Use your I4GL
Business
Logic with
Message
Queues
Webinventory.egl
DB2
HTML
Output
IDS
XML
Output
PDF
Output
C functions
Text
Reports
SchemaLib.egl
BL
BL
main.egl
BL
BL
inventory.egl
catalog.egl
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February 2, 2005
c_code.so
IBM Software Group / DB2 Information
Management
EGL Releases…
 6.0 ega 12/3/2004, GA 1/7
 fix001 ega 12/20/2004
(first release for Informix)
 ifix003 ega 2/28/2005 (Release with conversion
tool available through Rational updater).
 6.0.0.1 ega 4/8/2005 (Conversion tool available
through Rational updater)
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EGL information
 EGL site
http://www-128.ibm.com/developerworks/rational/products/egl/
 EGL downloads
http://www-106.ibm.com/developerworks/rational/library/egldoc.html
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http://www.ibm.com/software/data/informix
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© 2005 IBM Corporation
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