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<DIV><FONT face=Arial size=2><<<</FONT></DIV>
<DIV><FONT face=Arial color=#0000ff size=2>So in the calling db there's a
reference to the library and I can just use the property without declaring a
variable for it anywhere? Neat.</FONT></DIV>
<DIV><FONT face=Arial size=2>>>></FONT></DIV>
<DIV><FONT face=Arial size=2>Yes, Jim,</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>But there is an overhead on using Property Get with
testing for Is Nothing...</FONT></DIV>
<DIV><FONT face=Arial size=2>And such calls cannot be used in
queries...</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>But IMO all that can be neglected - do you
see any more severe side-effects of this technoque?</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>><FONT color=#0000ff>'m familiar with
PublicNotCreatable instancing in VB6</FONT></FONT></DIV>
<DIV><FONT face=Arial size=2>In VB6 it's better to use GlobalMultiUse attribute
value in ActiveX DLL lib(s) of class modules of utility/generic
code.</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>Strange they (MS) didn't do/let to the same
attributes for MS Access custom class modules...</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>Shamil</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<BLOCKQUOTE
style="PADDING-RIGHT: 0px; PADDING-LEFT: 5px; MARGIN-LEFT: 5px; BORDER-LEFT: #000000 2px solid; MARGIN-RIGHT: 0px">
<DIV style="FONT: 10pt arial">----- Original Message ----- </DIV>
<DIV
style="BACKGROUND: #e4e4e4; FONT: 10pt arial; font-color: black"><B>From:</B>
<A title=Jdemarco@hshhp.org href="mailto:Jdemarco@hshhp.org">Jim DeMarco</A>
</DIV>
<DIV style="FONT: 10pt arial"><B>To:</B> <A title=accessd@databaseadvisors.com
href="mailto:accessd@databaseadvisors.com">accessd@databaseadvisors.com</A>
</DIV>
<DIV style="FONT: 10pt arial"><B>Sent:</B> Saturday, February 08, 2003 4:59
PM</DIV>
<DIV style="FONT: 10pt arial"><B>Subject:</B> RE: [AccessD] Standard vs. Class
Module: RESEND</DIV>
<DIV><FONT face=Arial size=2></FONT><FONT face=Arial size=2></FONT><BR></DIV>
<DIV><SPAN class=951225513-08022003><FONT face=Arial color=#0000ff
size=2>Thanks Shamil. I'm familiar with PublicNotCreatable
instancing in VB6 but haven't really touched Access Libraries.
Interesting technique. So in the calling db there's a reference to the
library and I can just use the property without declaring a variable for it
anywhere? Neat.</FONT></SPAN></DIV>
<DIV><SPAN class=951225513-08022003><FONT face=Arial color=#0000ff
size=2></FONT></SPAN> </DIV>
<DIV><SPAN class=951225513-08022003><FONT face=Arial color=#0000ff size=2>BTW,
I finally see these messages I was having trouble with a day or more after I
sent them. Go figure.</FONT></SPAN></DIV>
<DIV><SPAN class=951225513-08022003><FONT face=Arial color=#0000ff
size=2></FONT></SPAN> </DIV>
<DIV><SPAN class=951225513-08022003><FONT face=Arial color=#0000ff size=2>Jim
DeMarco</FONT></SPAN></DIV>
<BLOCKQUOTE dir=ltr style="MARGIN-RIGHT: 0px">
<DIV class=OutlookMessageHeader dir=ltr align=left><FONT face=Tahoma
size=2>-----Original Message-----<BR><B>From:</B> Shamil Salakhetdinov
[mailto:shamil@smsconsulting.spb.ru]<BR><B>Sent:</B> Wednesday, February 05,
2003 6:05 PM<BR><B>To:</B> accessd@databaseadvisors.com<BR><B>Subject:</B>
Re: [AccessD] Standard vs. Class Module: RESEND<BR><BR></FONT></DIV>
<DIV><FONT face=Arial size=2><<<</FONT></DIV>
<DIV>
<DIV><SPAN class=716064013-05022003><FONT face=Arial color=#0000ff
size=2>Dim oUtil As cUtil</FONT></SPAN></DIV>
<DIV><SPAN class=716064013-05022003><FONT face=Arial color=#0000ff
size=2> Set oUtil = New cUtil</FONT></SPAN></DIV>
<DIV><SPAN class=716064013-05022003><FONT face=Arial color=#0000ff
size=2> oUtil.IsLoaded "myform"</FONT></SPAN></DIV></DIV>
<DIV><FONT face=Arial size=2>>>></FONT></DIV>
<DIV><FONT face=Arial size=2>Jim,</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>For utility classes you'd better use what is
called singleton classes/object instances:</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>- let's image your custom class is called
CMyClass and it has only one method </FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>Public Function Test()<BR> MsgBox
"TEST"<BR>End Function</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>- let's also imagine/assume that this class is
located in MS Access library database and that is has its Instancing
prioperty set to "2 - PublicNotCreatable"</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>- then you can create a standard helper module
with the following code:</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>Private mobjCMyClass As CMyClass</FONT></DIV>
<DIV> </DIV>
<DIV><FONT face=Arial size=2>Public Property Get CMyClass() As
CMyClass<BR> If mobjCMyClass Is Nothing Then<BR> Set
mobjCMyClass = New CMyClass<BR> End If<BR> Set CMyClass =
mobjCMyClass<BR>End Property</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>- having all that you can call your custom
class' CMyClass Test method by simply using the following code
line:</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>CMyClass.Test</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>- and you guaranteed to have only one instance
of your custom class during your app lifetime and you've type
ahead/intellisense while you typing your code even if your custom class is
located in library database and you don't need to type three code lines to
call one utility method of your utility/generic function custom
class...</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>Just some info on singletons and other custom
classes' usage "tricks",</FONT></DIV>
<DIV><FONT face=Arial size=2>Shamil</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<BLOCKQUOTE
style="PADDING-RIGHT: 0px; PADDING-LEFT: 5px; MARGIN-LEFT: 5px; BORDER-LEFT: #000000 2px solid; MARGIN-RIGHT: 0px">
<DIV style="FONT: 10pt arial">----- Original Message ----- </DIV>
<DIV
style="BACKGROUND: #e4e4e4; FONT: 10pt arial; font-color: black"><B>From:</B>
<A title=Jdemarco@hshhp.org href="mailto:Jdemarco@hshhp.org">Jim
DeMarco</A> </DIV>
<DIV style="FONT: 10pt arial"><B>To:</B> <A
title=accessd@databaseadvisors.com
href="mailto:accessd@databaseadvisors.com">accessd@databaseadvisors.com</A>
</DIV>
<DIV style="FONT: 10pt arial"><B>Sent:</B> Wednesday, February 05, 2003
8:50 PM</DIV>
<DIV style="FONT: 10pt arial"><B>Subject:</B> RE: [AccessD] Standard vs.
Class Module: RESEND</DIV>
<DIV><BR></DIV>
<DIV><SPAN class=716064013-05022003><FONT face=Arial color=#0000ff
size=2>Sent early AM and so sign of this one.</FONT></SPAN></DIV>
<DIV><SPAN class=716064013-05022003><FONT face=Arial color=#0000ff
size=2></FONT></SPAN> </DIV>
<DIV><SPAN class=716064013-05022003><FONT face=Arial color=#0000ff
size=2></FONT></SPAN> </DIV>
<DIV><SPAN class=716064013-05022003><FONT face=Arial color=#0000ff
size=2>No clear cut answer to this question. I normally put any code
that I feel I will reuse in a class module (by reuse I mean within the
same app only, or many apps). A couple of
examples:</FONT></SPAN></DIV>
<DIV><SPAN class=716064013-05022003><FONT face=Arial color=#0000ff
size=2></FONT></SPAN> </DIV>
<DIV><SPAN class=716064013-05022003><FONT face=Arial color=#0000ff
size=2>1. I used to have a problem remembering the provider/connect string
for Access and SQL OLEDB provides used when opening an ADO connection
and/or recordset(s). I wrapped the code I use to open connections
and create recordsets in a class, cDatabase. Now when I want to use
ADO I create an object of type cDatabase, call the OpenConnection method,
pass in the mdb or SQL DB, and pass a parameter telling the class what
type of db I'm using and I've got my connection.</FONT></SPAN></DIV>
<DIV><SPAN class=716064013-05022003><FONT face=Arial color=#0000ff
size=2>Ex.</FONT></SPAN></DIV>
<DIV><SPAN class=716064013-05022003><FONT face=Arial color=#0000ff
size=2><snip></FONT></SPAN></DIV>
<DIV><SPAN class=716064013-05022003><FONT face=Arial color=#0000ff
size=2>Dim oDB As cDatabase</FONT></SPAN></DIV>
<DIV><SPAN class=716064013-05022003><FONT face=Arial color=#0000ff
size=2>Dim rs As ADODB.Recordset</FONT></SPAN></DIV>
<DIV><SPAN class=716064013-05022003> <FONT face=Arial
color=#0000ff size=2>Set oDB = New cDatabase</FONT></SPAN></DIV>
<DIV><SPAN class=716064013-05022003><FONT face=Arial color=#0000ff
size=2> oDB.OpenConnection "mydb.mdb" 'mdb is default so
we don't have to pass optional db type argument</FONT></SPAN></DIV>
<DIV><SPAN class=716064013-05022003><FONT face=Arial color=#0000ff
size=2> Set rs = oDB.OpenRecordset
("mytablequeryorsql")</FONT></SPAN></DIV>
<DIV><SPAN class=716064013-05022003><FONT face=Arial color=#0000ff
size=2></snip></FONT></SPAN></DIV>
<DIV><SPAN class=716064013-05022003><FONT face=Arial color=#0000ff
size=2>I don't have to remember or find the provider/connect string
anymore.</FONT></SPAN></DIV>
<DIV><SPAN class=716064013-05022003><FONT face=Arial color=#0000ff
size=2></FONT></SPAN> </DIV>
<DIV><SPAN class=716064013-05022003><FONT face=Arial color=#0000ff
size=2>2. I wrote some code that reads setup/configuration settings from
an XML file. Once it was done I realized I'd like to add this
functionality to more apps so I ported it into a class module. Now
with no knowledge of XML my team of developers can add this
functionality to their apps by importing the class
module.</FONT></SPAN></DIV>
<DIV><SPAN class=716064013-05022003><FONT face=Arial color=#0000ff
size=2></FONT></SPAN> </DIV>
<DIV><SPAN class=716064013-05022003><FONT face=Arial color=#0000ff
size=2>This is not to say a one-off class is not out of the realm of
possibility. As J. Colby mentioned in a earlier post, if you need
certain functionality in more than one place in a single app classes make
it very easy to add that functionality without copy/paste or reviewing a
code module to see "how it works" or how to use it.
</FONT></SPAN></DIV>
<DIV><SPAN class=716064013-05022003><FONT face=Arial color=#0000ff
size=2></FONT></SPAN> </DIV>
<DIV><SPAN class=716064013-05022003><FONT face=Arial color=#0000ff
size=2>We all have stand alone functions that belong in standard
modules. One common module (here at least) is basUtil containing
utility functions like IsLoaded to check whether a form or Access object
is currently open (things not related to the function of the
system). There's nothing stopping you from putting those in a
class. Why bother? Class objects implement type ahead code
functionality. Imagine then how easy it would be to access your
utility functions by calling an object of type cUtil as
follows:</FONT></SPAN></DIV>
<DIV><SPAN class=716064013-05022003><FONT face=Arial color=#0000ff
size=2><snip></FONT></SPAN></DIV>
<DIV><SPAN class=716064013-05022003><FONT face=Arial color=#0000ff
size=2>Dim oUtil As cUtil</FONT></SPAN></DIV>
<DIV><SPAN class=716064013-05022003><FONT face=Arial color=#0000ff
size=2> Set oUtil = New cUtil</FONT></SPAN></DIV>
<DIV><SPAN class=716064013-05022003><FONT face=Arial color=#0000ff
size=2> oUtil.IsLoaded "myform"</FONT></SPAN></DIV>
<DIV><SPAN class=716064013-05022003><FONT face=Arial color=#0000ff
size=2></snip></FONT></SPAN></DIV>
<DIV><SPAN class=716064013-05022003><FONT face=Arial color=#0000ff
size=2>I'd normally have to take a look at basUtil to see what
functionality was in there but the class object's type ahead would
alleviate that (actually, this was a last minute thought but I think I'll
give it a try!).</FONT></SPAN></DIV>
<P><FONT face=Arial><FONT size=2><SPAN
class=716064013-05022003>HTH</SPAN>,</FONT></FONT> </P>
<P><FONT face=Arial size=2>Jim DeMarco</FONT> <BR><FONT face=Arial
size=2>Director of Product Development</FONT> <BR><FONT face=Arial
size=2>HealthSource/Hudson Health Plan</FONT> </P>
<BLOCKQUOTE dir=ltr style="MARGIN-RIGHT: 0px">
<DIV class=OutlookMessageHeader dir=ltr align=left><FONT face=Tahoma
size=2>-----Original Message-----<BR><B>From:</B> Myke Myers
[mailto:mmmtbig@bellsouth.net]<BR><B>Sent:</B> Monday, February 03, 2003
6:44 PM<BR><B>To:</B> accessd@databaseadvisors.com<BR><B>Subject:</B>
[AccessD] Standard vs. Class Module<BR><BR></FONT></DIV>
<DIV><FONT face=Arial size=2><SPAN class=859564123-03022003>Can anyone
describe how to determine when to use a standard module and when to use
a class module in Access?</SPAN></FONT></DIV>
<DIV><FONT face=Arial size=2><SPAN
class=859564123-03022003></SPAN></FONT> </DIV>
<DIV><FONT face=Arial size=2><SPAN
class=859564123-03022003>TIA Myke</SPAN></FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV></BLOCKQUOTE><CODE><FONT
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