Point of confusion - Custom Properties

[Jim Ault]

On 4/26/06 4:13 PM, "Phil Davis" <davis.phil at comcast.net> wrote:

> Jim Ault wrote:
>> I am trying to grasp how the setProp and getProp handers will work and am
>> stuck on the following concept.
>> 
>> Given: that executing the following lines will 'attempt' to change the
>> values of custom properties and send a message to do so ...
>> on opencard
>>   set the dontShowError of this stack to "true"
>>   set the dontShowIcons of this stack to "true"
>>   set the dontShowAnimation of this stack to "true"
>> end opencard
>> 
>> ---how can another handler be triggered while this one is running?
> 
> Hi Jim,
> 
> 'getProp' and 'setProp' have nothing to do per se with custom
> properties. They are just syntax alternatives to 'on' or 'function'.
> Your 'dontShow...' handlers would be executed much the same way any
> other function or custom command issued by 'openCard' would be executed.
> 
> (Warning - TMI follows) Execution of 'openCard' is paused/suspended, and
> Rev gives control to the called handler. In turn, the called handler may
> call other handlers and have its own execution paused until control
> comes back from the handler it called. When the original called handler
> finishes running, control is returned to the original caller (openCard)
> and its execution continues. (Unless of course a called handler 'short
> circuits' normal control with an 'exit to top' or some such thing.)
> 
> Is that what you're asking about?
> 
> Phil Davis
Hmmm, then I am really confused.  The docs for 2.6.1 Mac OSX say...

---------------------------------------------------
When you change a custom property, Revolution sends a setProp trigger to the
object whose property is being changed. You can write a setProp handler to
trap this trigger and respond to the attempt to change the property. Like a
message, this trigger uses the message path, so you can place the setProp
handler anywhere in the object's message path.

Similarly, when you get the value of a custom property, Revolution sends a
getProp call to the object whose property is being queried. You can write a
getProp handler to reply to the request for information. Like a function
call, the getProp call also traverses the message path.

Using getProp and setProp handlers, you can:
* validate a custom property's value before setting it
* report a custom property's value in a format other than what it's stored
as
* ensure the integrity of a collection of properties by setting them all at
once 
* change an object's behavior when a custom property is changed

  Note:  setProp triggers and getProp calls are not sent when a built-in
property is changed or accessed. They apply only to custom properties.
--------------------------------------------------------------------------
The triggers are what I want to take advantage of, rather than build script
lines to do the same thing.

This is probably like using 'wait with messages' and 'send in 2 seconds',
but it is not clear.

Thanks for the quick reply, but I think there is more to the story.

Jim Ault
Las Vegas