UNIFACE Development Guidelines - Overview

Tony Marston - 10th June 2000
amended 3rd July 2002

1. Introduction

The purpose of software development is to turn user requirements into usable software as quickly as possible. In order to achieve this it is necessary to have a suitable development language, knowledge of how that language works, and a development infrastructure coupled with suitable development standards. Most languages don’t come with a ready-made infrastructure, therefore it is necessary to create one before the development team can reach acceptable levels of productivity.

The documents which are the subject of this overview describe the standards and guidelines which I have put together after several years of developing client/server systems in UNIFACE, and many years in developing on-line systems in other languages prior to this. As well as giving my advice on how things can be done I am also making available a version of my development environment which contains working examples just to prove that my theories and methods actually work. Although these documents do not refer to every possible feature that is available within UNIFACE, they cover more than enough to give a developer who is new to UNIFACE a flying start.

All the documentation is available in Adobe PDF format, in zipped files.

1.1 UNIFACE Development Guidelines - Part 1 (Externals)

This provides a user’s view of the environment, and describes what facilities are available with their capabilities and limitations.

• System design - data modelling; database design; functional design; system security.
• Screen components - standard UNIFACE widgets and how they can be used; active field and occurrence highlighting; popup forms; action buttons; navigation buttons; shortcut keys; help options; column buttons.
• Standard dialog types - 50+ component templates categorised by their structure and behaviour.

1.2 UNIFACE Development Guidelines - Part 2 (Internals)

This provides a developer’s view of the environment.

• Object naming standards - application model; application library; templates; components.
• Development standards - the environment; application model; components.
• Coding standards - general standards; error handling; communication between objects; data validation; version tracking; use of selectdb; popup processing; updates across multiple forms; online help; sequence numbers; list processing; hit list processing.
• Tips and tricks - how to deal with null end dates; pausing retrieves of large tables.
• Standard entries - widgets; fonts; field templates; global procs; global variables; global messages; include procs.

1.3 UNIFACE Development Guidelines - Part 3 (Component Templates)

Describes in detail the component templates provided with this environment.

• How they are constructed - generic entities and fields; local constants; component variables.
• Trigger code - form level; entity level; field level; trigger inheritance.
• Features - communication between forms; using runtime options; initial values.
• Choosing a template - a full list of the capabilities of each component template.

1.4 UNIFACE Development Guidelines - Part 4 (Example System)

This provides a description of the XAMPLE system which provides working examples of each component template to demonstrate its characteristics.

• Form families - how individual components can be joined together into logical groups.
• Tree structures - how to build a flexible structure hierarchy with the tree widget.
• Tab pages - how to construct tab pages, either read only or to allow updates.
• Data unloading and reloading - how to save/restore selected data.
• Error handling - how to deal with errors detected in self-contained services.

1.5 UNIFACE Development Guidelines - Part 5 (3 Tier Development)

This has all the business logic extracted from the form components and built into separate business layer components known as session services. The forms now contain only presentation logic and communicate with business layer components using disconnected record sets contained within XML streams.

1.6 Menu & Security System User Guide

This describes the menu and security system which can be used as the standard front end for any client/server application which was developed using these guidelines.

• Features - logon security; customisable menus; customisable security profiles; module-level security; item-level security; runtime switches; initial values; online Help subsystem (may be taken from the database or external HTML files); audit logging.
• Logical data model - database tables and relationships for the menu database.
• Assignment file settings.
• Form components - screen shots; descriptions; field validation rules.

1.7 Demonstration Application & sample source code

Demonstration versions of this development environment, which include the menu and security system, the example application, component templates, application models, et cetera, are available for download from my web site at the address provided below. The original version was built using the 2-tier architecture, while a later version was built using the 3-tier architecture.

Tony Marston
10th June, 2000

mailto:tony@tonymarston.net
mailto:TonyMarston@hotmail.com
http://www.tonymarston.net

Amendment history: