Welcome
Developing
Developing EGL applications
Enterprise Generation Language (EGL) is a programming language that you can use to focus on business problems instead of software technologies. Within the Rational® development environment, you can use EGL wizards and other tools to write complex applications with minimal effort.
EGL Language Reference
The EGL Language Reference covers the fundamental use of the language, including its concepts, syntax, and keywords. This volume is intended for a developer writing EGL applications with some experience in procedural programming.
EGL statements
Transfer of control across programs

Overview
Getting started
Installing
Upgrading and migrating
Developing
- Model driven development of EGL code
- Generating source code from UML models
  You can use transformations to create source code from a UML model. First you must create a transformation parameters file and then apply those parameters to a model.
- Developing EGL applications
  Enterprise Generation Language (EGL) is a programming language that you can use to focus on business problems instead of software technologies. Within the Rational® development environment, you can use EGL wizards and other tools to write complex applications with minimal effort.
  - How to use this documentation
  - Additional information about EGL
    The most recent EGL documentation is in the Rational® Business Developer Information Center.
  - EGL Programmer's Guide
    The EGL Programmer's Guide covers using EGL within the Eclipse Integrated Development Environment (IDE), as well as some of the common programming tasks that EGL developers perform.
  - EGL Generation Guide
    The EGL Generation Guide covers the process of converting EGL code to Java™ or COBOL source code, including the processes and the files involved. This section is intended for a developer who will generate or deploy EGL applications.
  - EGL Language Reference
    The EGL Language Reference covers the fundamental use of the language, including its concepts, syntax, and keywords. This volume is intended for a developer writing EGL applications with some experience in procedural programming.
    - General syntax
    - System data parts
    - User-defined data parts
    - Logic parts
    - Correspondence between a JSON string and an EGL variable
      This topic describes the EGL record that corresponds to a JavaScript™ Object Notation (JSON) string. Other topics describe the functions (serviceLib.convertFromJSON() and serviceLib.convertToJSON()) that are used by a Rich UI developer to convert JSON data to or from a variable, as may be necessary to access a third-party REST service. A failure in either function causes a RuntimeException.
    - Correspondence between an XML string and an EGL variable
      This topic describes the EGL record that corresponds to an Extensible Markup Language (XML) string. Other topics describe the functions (serviceLib.convertFromXML and serviceLib.convertToXML) that are used by a Rich UI developer to convert XML data to or from a variable, as may be necessary to access a third-party REST service.
    - EGL statements
      - Comments
      - Data movement
      - Conditional and loop statements
      - Transfer of control within a program
      - Transfer of control across programs
        Transfer of control statement properties
        Run unit
        Using linkage options parts in a call or transfer
        call
        The EGL call statement transfers control from a main program to a called program; the called program returns control to the main program when it ends.
        forward
        transfer
        A transfer statement transfers control from one main program to another, ending the source program. The source program can optionally pass a record into the input record of the target program. The transfer statement is not valid in a called program.
      - Exception handling
    - EGL core system libraries and variables
    - Accessing data in EGL
      Whenever you access a data store in EGL, the data goes into a record.
    - Applications with user interfaces
    - VisualAge® Generator compatibility
    - Appendices
    - Importing product-supplied projects
      You can click a link to download the current version of Rich UI projects. The capability is useful if you deleted a project or want a clean version.
  - Rational® COBOL Runtime Guide for zSeries®
    This manual provides information about customizing and administering the IBM® Rational® COBOL Runtime.
  - Rational® Business Developer EGL Server Guide for IBM® i
    This manual provides information about customizing and administering EGL Server for IBM® i on the host.
  - Generation for VSE Feature Reference
    This reference manual provides z/VSE-specific information about developing and generating EGL programs in the VSE environment.
- Source code analysis with code review
  With code review, you can create configurations of coding rules for EGL source code. You can then run the configurations to check the source code for consistency with the rules.
- Responsive Design Support in RBD
  What is Responsive Design? Responsive design is an approach for creation of web pages that automatically scales its content and elements to match the screen size on which it is viewed. So, instead of designing multiple websites for different devices with variable screen sizes, we can design just one website that scales up or down automatically, to match the device it’s being viewed on.
Samples
Troubleshooting and support
Reference
Glossary
Using the help
Notices for IBM Rational Business Developer documentation

Transfer of control across programs

In addition to passing control from one function to another, there are several different ways to switch control from one program to another in EGL:

The call statement passes control from a function to a called program and optionally passes a series of values. (For more information, see Main versus called programs.) Control returns to the caller when the called program ends. If the called program changes any data that was passed as a variable, the content of the variable is changed in the caller.
The call does not commit databases or other recoverable resources, although an automatic server-side commit might occur.
The program is either generated by EGL or is considered externally defined. For more information on this subject, see Using linkage options parts in a call or transfer.
There is no practical limit to the number
Two types of transfer statements give control from one main program to another, end the transferring program, and optionally pass a record whose data is accepted into the input record of the receiving program.
- A transfer to transaction statement is available in most environments, and has the ability to commit or roll back recoverable resources.
- A transfer to program statement does not commit or roll back recoverable resources, but closes files, releases locks, and starts a program in the same run unit.
The vgLib.startTransaction() system function starts a run unit asynchronously. The operation does not end the transferring program and does not affect the databases, files, and locks in the transferring program. You have the option to pass data into the input record of the receiving program.
Use the EGL show statement within the context of specific UI technologies only. See the related reference at the end of the topic for any technologies that you might be using.
Use the EGL forward statement in a program that runs in a Java™ environment or in a UI context only. The statement performs the following actions:
1. Commits recoverable resources, closes files, and releases locks
2. Forwards control
3. Ends the code
The target in this case is another program or a web page. For details, see forward.