Handlers and Scope

[Adam]

Trevor DeVore wrote:
> On Dec 7, 2005, at 6:47 AM, Adam wrote:
> 
>>
>> I am then trying to call that function from the script of a button  on 
>> the card in the following way:
>>
>> on mouseUp
>>   put field "fldItemsToFind" into lItemsToFind
>>   put field "fldNumItemsAllowed" into lNumItemsAllowed
>>   fMyFunction(lItemsToFind,lNumItemsAllowed)
>> end mouseUp
>>
>> When put it into browse mode and click the button, I get Rev  telling 
>> me it can't find the handler fMyFunction.
> 
> 
> When you call a function you have to put the result of the function  
> into a variable.  There are two approaches:
> 
> get fMyFunction(lItemsToFind,lNumItemsAllowed)
> or
> put fMyFunction(lItemsToFind,lNumItemsAllowed) into tResult
> 
> The first is the Transcript short hand which puts the result returned  
> from the function into the "it" variable.  The second version stores  
> the result in tResult.  Another way to call the function is -
> 
> put fMyFunction(lItemsToFind,lNumItemsAllowed)
> 
> Which would print the result in the Revolution message box when  working 
> in the IDE.
> 
>> What is the scope of handlers in relation to the stack, cards in  the 
>> stack, and the elements of each card?
> 
> 
> Ah the message path.  In your example above the function could reside  
> in a number of places and still be called from the button script  
> without using "send" or "call" -
> 
> 1) The script of the button itself
> 2) If the button belongs to a group, the script of the group it  belongs 
> to.
> 3) The script of the card the button is on
> 4) The script of the stack the button is on
> 5) Any group scripts whose backgroundBehavior is set to true.
> 6) If the stack that the button is on is a substack of another stack  
> then the script of the main stack (see "mainstack" in the Rev  dictionary)
> 7) Any front or back scripts (see "insert script" in dictionary)
> 8) Any library stacks (see "start using" in dictionary).  This is my  
> favorite place to put scripts that I need anywhere in an application.
> 
> I think that covers all of the possibilities.  I would definitely  check 
> out an article on the message path that Richard Gaskin has  written 
> <http://www.fourthworld.com/embassy/articles/ 
> revolution_message_path.html>.  The message path is the other  
> Revolution concept that took me a while to grasp when coming from  other 
> programming languages like PHP and Flash.  Understanding the  message 
> path is key to writing libraries and frameworks for use in Rev.
> 

Hi again:

Within my application the fuctions I have written don't return values in 
that case, if I understand correctly; they should be handlers.  How do I 
define a handler?

Thanks,
Adam