The LA Fox Developer Newsletter

May 1998

An easy way to...

Add Field-Level Help to

Your Data Entry Forms

Use this generic help panel to guide your users through your

data-entry forms.

There are five obvious ways of providing help for data-entry

operators in Visual FoxPro:

1. Write a help topic for the data-entry form; invoke it with the

HELP and/or SET TOPIC commands.

2. Associate a help topic with the field’s HelpContextlD

property; the topic will be displayed when the user hits Fl.

3.

Use the WhatsThisHelp system; this lets the user select

the Help icon in the form’s title bar, then point and click on a

field to get help (in VFP 5.0 and above only).

4.

Display the help text as a tooltip.

5.

Display the help text on the status bar, using either SET

MESSAGE TO or the StatusBarText property.

The first three are fine if the user only needs occasional help.

But, because they require specific action on the user’s part,

they are less suitable for people who need constant guidance

on every field.

Tooltips are usually a good option, but they offer only limited

space for the help messages, they are distracting to experi-

enced operators (you need to provith a way to turn them off),

and they are of no help to non-mouse users.

As for status bar text, users don’t always like having to shift

their gaze from the form to the foot of the screen. Besides, the

FoxPro status bar has an old-fashioned feet. Many developers

switch it off to avoid users having to see record numbers,

locking messages and the like.

Another Ootion

We’d like to tell you about another option for field-level help —

one which we have used successfully in several applications. It

is completely generic and requires only a few of tines of code to

implement. Our users like it because it is non-intrusive and

does not demand any action on their part. Best of all, it does

not require you to write help topics or keep track of context lDs.

To the user, the help text appears on a small panel at the foot of

the data-entry form (see Figure 1). The text is displayed auto-

matically as the user moves focus from field to field. We use a

gentle color combination for the text — blue on gray is a favorite

choice — as this makes it easy for users to ignore the mes-

sage if they don’t need to see it.

What’s interesting about this technique is that the help text is

not stored in the application. Nor is it in a help file. It is held in

the field’s Comment property within the database. The advan-

tage of this is that the text can be maintained centrally. You

only need one instance of the help message per field, and, if

you need to change it, you only have to do so in one place.

Figure 1: A help message for the field in focus appears in a

small panel at the foot of the form.

Imølementation

To implement the technique, first add the help panel to your

base data-entry form. The panet is simply a label with a different

background color from the rest of the form. We generally set its

BorderStyle property to Fixed Single and its WordWrap property

to.T.

Next, add a custom method to the base form. Call it, say,

ShowHelp. The method simply displays, in the label, whatever

text is passed to it as a parameter, like this:

LPARAMETER cTextToShow

THIS.HelpPanel.Caption = clextToShow

(“HeipPanel” is the name of the label in this example.)

The next step is to arrange for each field in the form to call the

method and to pass it a parameter as it receives focus. The

obvious place to do that is in the GotFocus event of the data-

entry field’s base class. The code might look like this:

THISFORM.ShowHelp(DBGETPROP(THIS.ControlSource,”FieId”,”Commenr’))

For this to work, the field’s ControlSource must point to a field in

a database table. The database field’s Comment property

should contain the help text; you enter this through the Table

Designer. If you omit the text for a given field, no harm wilt be

done — the help panel will simply remain blank.

In case you are wondering, DBGETPROPO is a built-in VFP

function which, among other things, allows you to access any of

the field or table properties for any database table. You could

use itto get at the validation rules, the validation error mes-

sages, the format and input masks, and quite a lot more. See

the VFP help file if you’d like to know more.

(Con’t, page 8)

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