Recursion warning: what's the owner of a background?

[David Bovill]

Peter, not shure if I got you right?  Why not take:

word 1 to 3 of the long id of theObjectRef

In my case I need to check each level of the inheritance... if forgot that
using "pass" would get the same result in some cases (in mine I want to be
able to define getprop handlers anywhere in the hierarchy to override
default behavior).


On 23 December 2010 12:54, Peter Brigham MD <pmbrig at gmail.com> wrote:

> On Dec 23, 2010, at 6:34 AM, David Bovill wrote:
>
>  This one just caught me out. I have a script that checks a property of
>> it's
>> owner and returns the value. Specifically it checks the owner for a
>> property
>> of the same name to see when the local value is empty to see if it is
>> defined higher up in the object hierarchy. I thought this would be a safe
>> way of implementing object oriented stuff.
>>
>> But you get recursion when the control is a background, because the owner
>> of
>> a background is the card the background is on, but the card is actually
>> below the background in the message hierarchy, so the background script
>> gets
>> triggered again when you look for it in the backgrounds owner.
>>
>> A recursive tongue twister maybe - but just remember a background's owner
>> is
>> itself in scripting terms!
>>
>
> On the other hand, this utility function works fine for me:
>
> function masterBG theObjectRef
>   put the long id of the owner of theObjectRef into onr
>   if word 1 of onr = "card" then
>      return theObjectRef
>   else
>      return masterBG(onr)
>   end if
> end masterBG
>
> It returns the highest level group a control belongs to. I have a stack
> with two major backgrounds (switch between making one or the other visible
> with a button). In my custom find function I need to know which master
> background the foundfield is part of, and it may be nested in lower level
> groups, so this tells me which bg to show when a string is found, and it
> works reliably without the recursion problem above.
>
> -- Peter
>
> Peter M. Brigham
> pmbrig at gmail.com
> http://home.comcast.net/~pmbrig <http://home.comcast.net/%7Epmbrig>
>
>
>
> _______________________________________________
> use-livecode mailing list
> use-livecode at lists.runrev.com
> Please visit this url to subscribe, unsubscribe and manage your
> subscription preferences:
> http://lists.runrev.com/mailman/listinfo/use-livecode
>