Notes on Naming Conventions

Software Customisation Guide

Variables, Objects, Functions and Methods : Creating Variables (Objects) : Notes on Naming Conventions

Use a naming convention to avoid 'polluting the namespace’ of global variables. All global names beginning with the letters CD are reserved for AVEVA system use.

Note:

The most recent AVEVA Applicationware (AppWare) does not use a prefix. When creating new PML Macros the user is responsible for avoiding name-clashes, for example, by using their own prefix.

Here are some guidelines on naming variables:

•

Use each variable for one purpose only and give it a meaningful name.

•

Limit the use of global variables.

•

Where possible use PML Object methods and Form methods instead of PML functions and macros so as to make use of their members and methods which minimises use of global variables.

•

Remember that within the methods of PML Objects and Forms the user generally needs only local variables. Any values which are to be exported should be made available as members or as method values or returned arguments.

•

Only use PML Functions (necessarily global) for tasks which are genuinely globally accessible, i.e. independent of a specific object or form, or which need to be shared by several objects or forms.

Current Global Variables


Application	Prefix	Comments
Area Based ADP	!!ABA	Add-in application
Administration	!!ADM	Plus !!CDA
Application Switching	!!APP
Batch Handling	!!BAT
CADCentre	!!CADC
Draw	!!CDR
Draw Icon Location	!!CD2D	Icon pathnames
Defaults	!!DFLTS
General	!!CDC	Plus !!CDD, E, F, G, H, I, L, M, N, P, S, U, V, W
Specialised	!!CE	Plus !!ERROR, !!FMSYS, !!CMSYS
Various Others