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16. |
Q:
Is there any way I can ease my RPG controls on
numeric input fields? How about an input date field?
A:
You may add some JavaScript to have this done.
Also in this case, however, we recommend your CGI
performs the appropriate checks (some Web users
disable JavaScript from their browsers).
In your JavaScript evaluation you should also
consider advantages ("pros") and disadvantages ("cons").
- pro.
User errors are more quickly communicated through
JavaScript (it runs on the client) than through
CGI response. JavaScript makes users more happy
in terms of faster diagnosis.
- con.
Imbedding JavaScript in your HTML would increase
the size of your page, and this might result to
a slightly slower response, expecially in cases
were the user connects through a slow line.
As to examples of JavaScript for controlling input fields,
you may look at our page
JavaScript examples:
regular expressions.
A little further you'll find a link
(Validating form numeric fields)
to a CGI performing through
JavaScript exactly what you're looking for.
Should you be interested, just download and install on your
AS/400 our library js2.
With regard to the checks your CGI should in any case,
here are our tips:
- If your CGI did initialize the input field,
on the next "call" it might just check whether
its new value is equal to initialized one.
If so, the field was not changed by the user.
- You might check numeric data through the
Mel's service program
chkNbr
subprocedure.
If you like to use subprocedure c2n2
instead, please note that it
ignores slashes but treats dashes as
minus signs.
- Another method would be to output the date as three fields in the form:
month, day, and year with separators as constants between them.
- Another method would be to output the date twice: once in edited form (
modifiable) and once as pure numerics (as an input field).
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