Newbie issue - fld vs bg field vs cd field

Devin Asay devin_asay at
Tue Mar 4 16:54:16 EST 2008

On Mar 4, 2008, at 2:38 PM, Timothy Miller wrote:

> Greetings,
> I'm don't quite understand when (or if) it is necessary to specify  
> cd fld "whatever"  vs bg fld "whatever"  vs  fld "whatever" in Rev.  
> When confusion arises, I'm solving it by trial and error. Some of  
> my stacks and scripts, retreaded from hypercard, require the  
> correct field or button specification, or there is "no such object."
> I once knew the rules in hyperCard, but they were rather confusing.  
> As I recall, fields were presumed cd fields, unless specified bg  
> fields, and buttons were presumed bg buttons, unless specified cd  
> buttons. As I recall, this was changed in Rev.
> It seems to matter that a field or button belongs to a group, if  
> "behave like a background" is turned on, but I'm not certain. I  
> looked at the Rev documentation, but couldn't find the explanation.
> A brief explanation of the rules for specifying fields and buttons  
> in Rev scripts would be appreciated. A link or documentation  
> citation will suffice.

As a rule you never have to specify bg or cd before an object  
reference in Revolution. The exception is when the stack property  
HCAddressing is true, which happens when you have done a direct  
import of a HyperCard stack. (See HCAddressing in the dictionary for  
more info.) You're right that the rules in HyperCard were a little  
confusing, and I don't miss the cd/bg distinction a bit.
> Is it better to ask newbie questions here or on the web forum?

In my experience the mail list is a little more active than the forum.



Devin Asay
Humanities Technology and Research Support Center
Brigham Young University

More information about the Use-livecode mailing list