Path: utzoo!attcan!uunet!mcvax!ukc!s1!jrwg
From: jrwg@s1.sys.uea.ac.uk (John Glauert CMP)
Newsgroups: comp.sys.mac.hypercard
Subject: Re: How can I get instance variables in buttons
Summary: Radio buttons: solution and problem
Message-ID: <185@s1.sys.uea.ac.uk>
Date: 14 Nov 88 11:23:43 GMT
References: <77053@sun.uucp> <4089@Portia.Stanford.EDU>
Distribution: comp
Organization: UEA, Norwich, UK
Lines: 59

In article <4089@Portia.Stanford.EDU>, duggie@Jessica.stanford.edu (Doug Felt) writes:
> In article <77053@sun.uucp> DATJN@NEUVM1.Bitnet (Jakob Nielsen Tech Univ of Denmark) writes:
> >I would like to be able to associate values with buttons
> >...
> >Do anybody have ideas for a cleaner way to program this??
> 
> Alas, one of the consequences of Hypertalk not being a full
> object-oriented language is the inability to create your own objects
> with state.  Anyone who has tried to hack radio button groups will
> understand this-- better still if they have tried to provide a 'tool'
> for a naive user to create radio button groups.
> ...

I am no expert Hypertext programmer so this may be naive, but the
scripts below do provide radio button groups: I use a hidden field to
hold the state of the group given by the id of the selected button;
blank implies no selection. Since button state is global, you need to
adjust it to the right value when the card is opened. Script fragments
below. A simplified version provides check boxes.

Now the problem: I want to print this stack, but my radio buttons are
not displayed properly because (it seems) opencard is not sent to
cards before they are printed (hence I get the current button state
everywhere).  What can I do?

John.

In the script of the stack:

on opencard
  set hilite of bkgnd button "M" to false
  set hilite of bkgnd button "F" to false
  if field "Gender" <> ""
  then
    set hilite of bkgnd button id (field "Gender") to true
  end if
end opencard

on radioclick group
  if field group = id of the target
  then
    set hilite of the target to false
    put "" into field group
  else
    if field group <> ""
    then
      set hilite of bkgnd button id (field group) to false
    end if
    set hilite of the target to true
    put id of the target into field group
  end if
end radioclick


The script of buttons "M" and "F":

on mouseUp
  radioclick "Gender"
end mouseUp