setprop handlers for custom property sets

[Peter M. Brigham]

On Jul 30, 2015, at 4:34 PM, Mark Wieder wrote:

> Paul Dupuis <paul at ...> writes:
> 
>> 
>> The LC 6.7.5 dictionary entry for setProp has the following:
>> 
>> If the custom property you want to control is in a custom property set,
>> use array notation in the first line of the setProp handler, as in the
>> following example:
> 
> Interesting. I do see that in the documentation, but I've never used that.
> The way I've always dealt with custom property sets is to switch context:
> 
> set the customPropertySet of <object> to <name>
> set the <property> of <object> to <whatever>
> get the <property> of <object>
> set the customPropertySet of <object> to empty
> 
> I think this makes for a cleaner, easier-to-read format anyway.

I use these, an easy and modular approach:

on setCustomProp pObjRef, pPropSet, pProp, pValue
   -- modeled after deleteCustomProp
   -- not sure where this comes from
   
   put the custompropertyset of pObjRef into oldPropSet
   set the custompropertyset of pObjRef to pPropSet
   set the pProp of pObjRef to pValue
   set the custompropertyset of pObjRef to oldPropSet
end setCustomProp

function getCustomProp pObjRef, pProp, pPropSet
   -- modeled after deleteCustomProp
   -- not sure where this comes from
   -- if pPropSet = empty then uses the default custompropertyset
   
   put the custompropertyset of pObjRef into oldPropSet
   set the custompropertyset of pObjRef to pPropSet
   put the pProp of pObjRef into tValue
   set the custompropertyset of pObjRef to oldPropSet
   return tValue
end getCustomProp

on deleteCustomProp pObjRef, pProp, pPropSet
   -- not sure where this comes from, it's not mine
   -- thanks to <whoever> !
   
   put the custompropertyset of pObjRef into oldPropSet
   set the custompropertyset of pObjRef to pPropSet
   put the customkeys of pObjRef into keysList
   set the wholematches to true
   put lineoffset(pProp,keysList) into propLine
   if propLine <> 0 then
      delete line propLine of keysList
      set the customkeys of pObjRef to keysList
   end if
   set the custompropertyset of pObjRef to oldPropSet
end deleteCustomProp

-- Peter

Peter M. Brigham
pmbrig at gmail.com
http://home.comcast.net/~pmbrig