[AccessD] Refreshing open forms when something changes

John,

<<2) I can if I wish create 1 to N (hundreds if I wish) different instances
of clsMsg and each 
"functional set" can grab a pointer to the clsMsg instance that it needs to
watch messages on.>>

  Then why did your intial post contain this sample code:

private sub mcMsg_Message(varFrom as variant, varTo as variant, varSubject
as variant, varMsg as 
variant)

	if VarFrom = "MyName" then
		if VarTo = "WhoThisIsGoingTo" then
			if VarSubject = "MySubject" then
				'Requery the combo
				MyCombo.requery
			endif
		endif
	endif
end sub

  It implies that it may receive events that don't pertain to it.  Other
wise, there would be no need for the first two If checks.  And if you
implemented a BO class as Drew outlined, there'd be no need for the third
either.

<<3) Most forms just "sit there" anyway.  The user is looking at the screen,
yaking on the phone, 
smoking a cigarette and oh yea, entering stuff.

Processing a message is going to take about... under a millisecond.
Probably a few hundred 
microseconds in fact.  So even if I have a dozen forms open at once, and all
of them use the message 
channel, how much machine time is actually used to process the message in
all the forms?>>

  Sorry, but to me, it's that type of thinking that has lead to bloated/slow
software.

Jim.



-----Original Message-----
From: accessd-bounces at databaseadvisors.com
[mailto:accessd-bounces at databaseadvisors.com] On Behalf Of jwcolby
Sent: Tuesday, June 21, 2011 12:55 PM
To: Access Developers discussion and problem solving
Subject: Re: [AccessD] Refreshing open forms when something changes

 > I think JC was talking about a messaging class for an example of using
events, not as his end all 
be all of using events.

Precisely.  In fact several things come into play here.

1) Only forms that grab a pointer to clsMsg and sink the events actually get
the message (have to 
process it).

2) I can if I wish create 1 to N (hundreds if I wish) different instances of
clsMsg and each 
"functional set" can grab a pointer to the clsMsg instance that it needs to
watch messages on.

3) Most forms just "sit there" anyway.  The user is looking at the screen,
yaking on the phone, 
smoking a cigarette and oh yea, entering stuff.

Processing a message is going to take about... under a millisecond.
Probably a few hundred 
microseconds in fact.  So even if I have a dozen forms open at once, and all
of them use the message 
channel, how much machine time is actually used to process the message in
all the forms?

 > I think JC was talking about a messaging class for an example of using
events, not as his end all 
be all of using events.

In my framework I have dozens of classes and they sink literally hundreds of
events.  The message 
class is nothing more than an example of using events to solve a specific
common problem.  We have 
all run into this "something happens over here and the combos over there are
not requeried".  I 
actually fixed this specific problem in this specific database using my
clsMsg.

BTW I have been using this for about 10 years now.

 From my framework, circa 12/2001:

'--------------------------------------------------------------------------
'.Written By   : John W. Colby
'.Date Created : 12/06/2001
'.Rev. History :
'.Comments     :
'.-------------------------------------------------------------------------
'.
' ADDITIONAL NOTES:
'
'The message class implements a Withevent / RaiseEvent communications method
'that can now be generically implemented using this class as the comm
object.

John W. Colby
www.ColbyConsulting.com

On 6/21/2011 12:21 PM, Drew Wutka wrote:
> Ummmmmm.... but that is only if you are creating an extremely broad and
> generic event process.
>
> In your example, of a customer being added, if I was developing a system
> I would have a 'customers' class, which had a 'New' (or changed)
> Customer event.  So only forms/windows/classes that interacted with the
> Customers class would have that event sunk, so that only those
> forms/windows/classes would do anything when that event was raised.
>
> I think JC was talking about a messaging class for an example of using
> events, not as his end all be all of using events.
>
> Drew
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