Accessing Functions in the Script of the Main Stack

J. Landman Gay jacque at
Wed Aug 24 14:52:38 EDT 2011

On 8/24/11 1:31 PM, Bob Sneidar wrote:
> I may misunderstand then. I thought that a library stack was enabled
> with the start using command, and that this is why the scripts run,
> because the stack script of a stack in use is inserted into the
> backscript. Am I wrong? If so, then how are the commands and
> functions in a library stack inserted into the message path?

I don't know if it's changed since the old MetaCard days, but back then 
Dr Raney explained one of the distinctions to me.

Stacks in use place their stack script into the message hierarchy just 
before the Home stack script. (In a standalone, Home is your mainstack.) 
This retains compatibility with HyperCard.

Scripts inserted "into back" are placed after the Home stack script; 
they are the last thing before the engine gets messages.

Another distinction is that any script of any object can be inserted 
into back (which allows a great deal of flexibility; the LiveCode IDE 
inserts button scripts into back to load things it needs.) But when a 
stack is put in use, only the stack script itself is inserted into the 
hierarchy; no other object scripts are available.

Libraries are strictly stacks in use.

Jacqueline Landman Gay         |     jacque at
HyperActive Software           |

More information about the Use-livecode mailing list