•The LA Fox Developer Newsletter

May 1995

Getting RAD With Application

Frameworks

By Kelly G. Conway, National Consulting Service

FoxPro has been a very successful product for

several years. Like any successful product, it has

spawned a healthy market for 3rd party tools.

Recently, I have reviewed several products in one

category of tools, Application Frameworks, and I

thought that I would share with you some of my

findings.

What is an application framework? By my definition,

an application framework is a well-defined library of

programs and “objects” that provides much of the

common functionality that most applications require.

Many application frameworks also provide tools that

may be used to speed development and/or mainte-

nance of applications. Most of the currently avail-

able application frameworks help you build general

data base applications. But some products are

designed to assist with you with a specific type of

application, such as accounting or manufacturing.

Examples of functions that application frameworks

can provide are generic entry screens, report

generators, database repair/re-indexing, system

security, user login, context-sensitive help,

modeless event handling, data validation and

referential integrity. Example development tools that

can be provided by application frameworks are data

dictionaries, data-entry screen generators, report

generators, application documenters and generic,

reusable routines such as table look-ups.

Armed with any of the application framework prod-

ucts on the market, you are ready to produce quick

prototypes that are robust and that virtually are

error-free. This is because the frameworks come

with pre-tested functionality that you merely plug

into your application. Sure, you’ll need to flesh out

the prototype and develop the procedures to imple-

ment functionality that is specific to each applica-

tion. But your initial effort can be much more pro-

ductive and can produce a prototype that is much

more impressive than you could accomplish by

coding from scratch. The completed application

also is easier to maintain because the framework

promotes consistency from one application to

another.

But why, you may be asking, should we consider

buying tools for use with FoxPro 2.x now with the

imminent release of Visual FoxPro? Won’t we be

wasting our money as well as the time that it takes to

learn to use the tools? Won’t Visual FoxPro make

development easier and/or provide the same function-

ality as these tools? These are good questions and,

obviously, ones that you will have to answer for your-

self. But here are some thoughts that may help you

make the decision.

Do you already have a standard development method-

ology, set of tools and library procedures for v2.X? If

you do, and if they cover at least most of the

functionality that your applications need, you may

not have a need for an application framework. But

you may want to take a look at some of the product

demos and see if you get any ideas for functions that

your applications currently are not providing.

If you don’t have a standard methodology or set of

tools, I suggest giving a long look at the available

framework products. Not only do they provide a strong

base from which your applications can be built, they

also are superior tools for learning FoxPro.

Do you anticipate supporting v2.X applications that

you currently are developing long after Visual Fox hits

the shelves? Once you get proficient with Visual Fox, it

will become more difficult to go back and maintain 2.X

applications. That difficulty would be eased by using a

specific methodology and set of tools for your 2.X

applications.

Do you anticipate converting some or all of your v2.X

applications to Visual Fox? Though Visual Fox will run

2.X applications unchanged, most people will want to

convert many of their applications to the new version.

Though Visual Fox provides tools to assist with that

conversion, no conversion ever is completely auto-

matic. The conversion process for multiple applications

would be eased if those applications all were based on

a specific methodology and set of tools.

Like anything else, there are disadvantages associ-

ated with using application frameworks too. For ex-

ample, some framework functions actually shield you

from what would be a complex FoxPro implementation

of a certain function. While this is an advantage where

(Con’t, page 8)

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