Release 10.1A: OpenEdge Development:
Messaging and ESB

Preface

This Preface contains the following sections:

Purpose
Audience
Organization
Typographical conventions
Examples of syntax descriptions
Example procedures
OpenEdge messages

Purpose

This manual provides overview information and programming guidelines for the Progress® OpenEdge® Adapters for SonicMQ® and Sonic ESB®. The SonicMQ Adapter and the Sonic ESB Adapter enable Progress 4GL applications to participate in the Sonic messaging and application integration environment.

Audience

This manual is primarily intended for programmers interested in developing services and clients for use in the Sonic environment. Knowledge of 4GL programming concepts and techniques is assumed, and a fundamental understanding of Web services technology is desirable.

This manual also includes general discussion of the Sonic environment and its relationship to the OpenEdge product suite, which may be of interest to a broader audience including architects, system administrators, and others.

Organization

Chapter 1 "OpenEdge Applications in the Sonic Environment"

Describes the SonicMQ Adapter and the Sonic ESB Adapter, and provides a brief overview of how the OpenEdge Adapter products function in the Sonic environment.

Chapter 2 "Introducing the OpenEdge Adapter for SonicMQ"

Explains basic concepts and general considerations for integrating 4GL applications with the JMS messaging service provided by SonicMQ.

Chapter 3 "Understanding the Messaging Models"

Explains the Point-to-Point (PTP) and Publish/Subscribe (Pub/Sub) JMS messaging models.

Chapter 4 "Implementing Messaging"

Describes how a 4GL client exchanges messages using the JMS messaging models.

Chapter 5 "Programming for the OpenEdge Adapter for SonicMQ with the 4GL-JMS API"

Provides instructions for using the 4GL-JMS API to program applications for the SonicMQ environment.

Chapter 6 "Guidelines for Using and Programming for the OpenEdge Adapter for Sonic ESB"

Provides general programming guidelines and compares the Sonic ESB Adapter with the OpenEdge Web Services Adapter (WSA). Because the two adapters are identical with respect to application development, programmers should refer to WSA documentation, as indicated in this chapter, for detailed information.

Appendix A, "4GL-JMS API Reference"

Provides an alphabetical API reference for the Progress SonicMQ Adapter.

Appendix B, "Messaging Examples"

Provides 4GL code examples of Pub/Sub and PTP messaging, and a sample application.

Typographical conventions

This manual uses the following typographical conventions:

Convention	Description
Bold	Bold typeface indicates commands or characters the user types, or the names of user interface elements.
Italic	Italic typeface indicates the title of a document, provides emphasis, or signifies new terms.
SMALL, BOLD CAPITAL LETTERS	Small, bold capital letters indicate OpenEdge® key functions and generic keyboard keys; for example, GET and CTRL.
KEY1+KEY2	A hyphen between key names indicates a simultaneous key sequence: you press and hold down the first key while pressing the second key. For example, CTRL+X.
KEY1 KEY2	A space between key names indicates a sequential key sequence: you press and release the first key, then press another key. For example, ESCAPE H.
Syntax:
Fixed width	A fixed-width font is used in syntax statements, code examples, and for system output and filenames.
Fixed-width italics	Fixed-width italics indicate variables in syntax statements.
Fixed-width bold	Fixed-width bold indicates variables with special emphasis.
UPPERCASE fixed width	Uppercase words are Progress® 4GL language keywords. Although these always are shown in uppercase, you can type them in either uppercase or lowercase in a procedure.
	This icon (three arrows) introduces a multi-step procedure.
	This icon (one arrow) introduces a single-step procedure.
Period (.) or colon (:)	All statements except DO, FOR, FUNCTION, PROCEDURE, and REPEAT end with a period. DO, FOR, FUNCTION, PROCEDURE, and REPEAT statements can end with either a period or a colon.
[ ]	Large brackets indicate the items within them are optional.
[ ]	Small brackets are part of the Progress 4GL language.
{ }	Large braces indicate the items within them are required. They are used to simplify complex syntax diagrams.
{ }	Small braces are part of the Progress 4GL language. For example, a called external procedure must use braces when referencing arguments passed by a calling procedure.
|	A vertical bar indicates a choice.
...	Ellipses indicate repetition: you can choose one or more of the preceding items.

Examples of syntax descriptions

In this example, ACCUM is a keyword, and aggregate and expression are variables:

Syntax

ACCUM aggregate expression

FOR is one of the statements that can end with either a period or a colon, as in this example:

FOR EACH Customer:   DISPLAY Name. END.

In this example, STREAM stream, UNLESS-HIDDEN, and NO-ERROR are optional:

Syntax

DISPLAY [ STREAM stream ] [ UNLESS-HIDDEN ] [ NO-ERROR ]

In this example, the outer (small) brackets are part of the language, and the inner (large) brackets denote an optional item:

Syntax

INITIAL [ constant [ , constant ] ]

A called external procedure must use braces when referencing compile-time arguments passed by a calling procedure, as shown in this example:

Syntax

{ &argument-name }

In this example, EACH, FIRST, and LAST are optional, but you can choose only one of them:

Syntax

PRESELECT [ EACH | FIRST | LAST ] record-phrase

In this example, you must include two expressions, and optionally you can include more. Multiple expressions are separated by commas:

Syntax

MAXIMUM ( expression , expression [ , expression ] ... )

In this example, you must specify MESSAGE and at least one expression or SKIP [ (n) ], and any number of additional expression or SKIP [ ( n ) ] is allowed:

Syntax

MESSAGE { expression | SKIP [ ( n ) ] } ...

In this example, you must specify {include-file, then optionally any number of argument or &argument-name = "argument-value", and then terminate with }:

Syntax

{ include-file     [ argument | &argument-name = "argument-value" ] ... }

Long syntax descriptions split across lines

Some syntax descriptions are too long to fit on one line. When syntax descriptions are split across multiple lines, groups of optional and groups of required items are kept together in the required order.

In this example, WITH is followed by six optional items:

Syntax

WITH [ ACCUM max-length ] [ expression DOWN ]   [ CENTERED ] [ n COLUMNS ] [ SIDE-LABELS ]   [ STREAM-IO ]

Complex syntax descriptions with both required and optional elements

Some syntax descriptions are too complex to distinguish required and optional elements by bracketing only the optional elements. For such syntax, the descriptions include both braces (for required elements) and brackets (for optional elements).

In this example, ASSIGN requires either one or more field entries or one record. Options available with field or record are grouped with braces and brackets:

Syntax

ASSIGN   { [ FRAME frame ] { field [ = expression ] }             [ WHEN expression ] } ...        | { record [ EXCEPT field ... ] }

Example procedures

This manual provides numerous example procedures that illustrate syntax and concepts. Examples appear in boxes with borders. If a procedure is available, its name appears above the box. If a procedure is not available it should compile as shown but might not execute for lack of completeness.

Accessing the sample files

The example files and instructions for installing the examples are available from the following locations:

The Documentation and Samples CD that you received with your product.
The Progress Documentation Web site:

http://www.progress.com/products/documentation

After you have installed the examples, you can find the samples for the OpenEdge Adapter for SonicMQ in the following location:

Doc_and_Samples_Install/src/samples/sonicmq/adapter/

OpenEdge messages

OpenEdge displays several types of messages to inform you of routine and unusual occurrences:

Execution messages inform you of errors encountered while OpenEdge is running a procedure; for example, if OpenEdge cannot find a record with a specified index field value.
Compile messages inform you of errors found while OpenEdge is reading and analyzing a procedure before running it; for example, if a procedure references a table name that is not defined in the database.
Startup messages inform you of unusual conditions detected while OpenEdge is getting ready to execute; for example, if you entered an invalid startup parameter.

After displaying a message, OpenEdge proceeds in one of several ways:

Continues execution, subject to the error-processing actions that you specify or that are assumed as part of the procedure. This is the most common action taken after execution messages.
Returns to the Progress Procedure Editor, so you can correct an error in a procedure. This is the usual action taken after compiler messages.
Halts processing of a procedure and returns immediately to the Progress Procedure Editor. This does not happen often.
Terminates the current session.

OpenEdge messages end with a message number in parentheses. In this example, the message number is 200:

** Unknown table name table. (200)

If you encounter an error that terminates OpenEdge, note the message number before restarting.

Obtaining more information about OpenEdge messages

In Windows platforms, use OpenEdge online help to obtain more information about OpenEdge messages. Many OpenEdge tools include the following Help menu options to provide information about messages:

Choose Help Recent Messages to display detailed descriptions of the most recent OpenEdge message and all other messages returned in the current session.
Choose Help Messages and then enter the message number to display a description of a specific OpenEdge message.
In the Progress Procedure Editor, press the HELP key or F1.