Limiting data entry in fields

[Jan Schenkel]

--- On Mon, 11/29/10, Monte Goulding <monte at sweattechnologies.com> wrote:
> Hi Charles
> 
> I'm a little confused about your requirements. Did you want
> to allow decimals or not? Here's some code copied from one
> of my behavior scripts. You only need to modify the one
> function to impose whatever data entry limits you like:
> 
> on keydown pKey
>    if checkText(getNewText(pKey)) then 
>       setNewText pKey
>    else 
>       beep 1
>    end if
> end keyDown
> 
> on pasteKey
>    if checkText(getNewText(the
> clipboardData["text"])) then 
>       paste
>    else
>       beep 1
>    end if
> end pasteKey
> 
> # This is the only function you need to change to vary the
> acceptable data entry
> private function checkText pText
>    return pText is an integer
> end checkText
> 
> private function getNewText pNewChars
>    local tEndChar,tStartChar,tText
>    put word 2 of the selectedchunk of me
> into tStartChar
>    put word 4 of the selectedchunk of me
> into tEndChar
>    put the text of me into tText
>    put pNewChars into char tStartChar to
> tEndChar of tText
>    return tText
> end getNewText
> 
> private command setNewText pNewChars
>    local tEndChar,tStartChar,tText
>    put word 2 of the selectedchunk of me
> into tStartChar
>    put word 4 of the selectedchunk of me
> into tEndChar
>    put pNewChars into char tStartChar to
> tEndChar of me
> end setNewText
> 
> Cheers
> 
> Monte
> 

Don't forget dragDrop :-)

Seriously, this is an old question that keeps coming back, and a prime candidate for either an engine-level field "mask", or a community effort to write a behavior script that handles the corner cases and is readily available for download.

A bit of searching turned up bits and pieces as far back as 2002 in my archives, but the combination of these two emails seems to do the trick:
<http://lists.runrev.com/pipermail/use-livecode//2002-October/008411.html>
<http://lists.runrev.com/pipermail/use-livecode//2003-September/022375.html>
(best to follow these links, as it looks like the post-rename archives are slightly misaligned)

While it does a bit too much for Charles' use case (formatting number for display) the underlying logic is sound. Thanks to Ken Ray for writing the RegEx back in 2002 to split a number into a sign, integer and decimal part.
<http://lists.runrev.com/pipermail/use-livecode//2002-September/008030.html>

Jan Schenkel.
=====
Quartam Reports & PDF Library for LiveCode
www.quartam.com

=====
"As we grow older, we grow both wiser and more foolish at the same time."  (La Rochefoucauld)