Coding Standards for Database Files › Coding Standards for Messages

Coding Standards for Messages

This section describes design and coding standards for messages. It explains how messages are used and provides standards for defining and sending messages.

The midrange architecture has fast, sophisticated message handling facilities you can use to send and receive messages in your own HLL programs. Messages can be used both as an invocation/return control mechanism and to handle text. This section mainly considers the latter.

OS/400 message descriptions provide a program - independent mechanism for storing natural language text fragments, thus making it possible to translate a system without changing the non-text objects in a system. When you build an application, you can use OS/400 messages in two different ways:

• As prompt messages: The text prompts used on commands, menus, panels, and reports, can all be isolated from the device file and command source and stored as external message definitions. Prompt messages normally only require first level text. (You may use the second level text for notes for translators).
• As execution messages: Execution messages are sent and received at execution. They both provide a control mechanism to determine the subsequent processing and can be used to provide the user with a natural language explanation of what has taken place or has gone wrong. They may have substitution variables and second level text.