Problem with eval function

  • Thread starter Thread starter NH
  • Start date Start date
N

NH

x-posted to:
microsoft.public.access.formscoding, microsoft.public.access.modulesdaovba


I am trying to run some 'user definable' code on a form using the Eval
function:

This works fine:

myCode = """This "" & ""is "" & ""a "" & ""test"""
Forms!MyForm.MyField = Eval(myCode)

But what I want is:

myCode = """Forms!MyForm.MyField"" & "" = "" & ""Test"""
Eval(myCode)

Am I doing something wrong, or is there another function capable of doing
what I want?

Can anyone suggest another way of doing it?

Thanks,

Nick
 
NH said:
I am trying to run some 'user definable' code on a form using the Eval
function:

This works fine:

myCode = """This "" & ""is "" & ""a "" & ""test"""
Forms!MyForm.MyField = Eval(myCode)

But what I want is:

myCode = """Forms!MyForm.MyField"" & "" = "" & ""Test"""
Eval(myCode)

Am I doing something wrong, or is there another function capable of doing
what I want?
Click to expand...


Eval evaluates an expression and returns its value, Eval can
not execute a statement. Only procedures in a module object
can execute VBA statements.
 
NH said:
myCode = """Forms!MyForm.MyField"" & "" = "" & ""Test"""
Eval(myCode)
Click to expand...

I don't know if Eval can even see controls on forms, but it if did, I guess
this would return False most of the time. If you want to set the value of a
form control, then just do it.

strFormName = "MyForm"
strControlName = "MyField"
strValueToSet = "Test"

Forms(strFormName).Controls(strControlName).Value = strValueToSet


There probably are such things, but I have not yet come across a legitimate
reason for using Eval... <ducks>

Hope that helps


Tim F
 
Thanks Tim,

I agree. I don't think eval is going to help me here.

Your way is much closer to what I want, but I need to get the code from a
string:

What I want is to effectively 'run' a string, I.e.

myStr= "If (Forms!MyForm.Text1 <> 1) then Forms!MyForm.Text2 = 2"
<run> myStr

I could break the string down into components, e.g.

strFormName = "MyForm"
strControl1 = "Text1"
strControl2 = "Text2"
strValueToSeek = "1"
strValueToSet1 = "2"

...and then use your suggestion..

If Forms(strFormName).Controls(strControl1).Value = strValueToSeek then
Forms(strFormName).Controls(strControlName).Value = strValueToSet

But the user's rule could be <>1 , =1, <1 , >1...........

That's where I am having trouble..



You see, I need my users to be able to add very simple rules into a table,
and then their rules run when the form is closed...
 
If you break it down to its component parts and the
statement is always the same style, then you can use Eval to
deal with the user's rule:

strFormName = "MyForm"
strControl1 = "Text1"
strControl2 = "Text2"
strUserRule= "<>1"
strValueToSet = "2"

If Eval("Forms!" & strFormName & "." & strControl1 _
& strUserRule) Then
Forms(strFormName).Controls(strControlName) _
= strValueToSet
End If
 
Ahh, there IS a reason to use Eval() after all...

I think that could work.

Thank you both for your help.

Nick

Marshall Barton said:
If you break it down to its component parts and the
statement is always the same style, then you can use Eval to
deal with the user's rule:

strFormName = "MyForm"
strControl1 = "Text1"
strControl2 = "Text2"
strUserRule= "<>1"
strValueToSet = "2"

If Eval("Forms!" & strFormName & "." & strControl1 _
& strUserRule) Then
Forms(strFormName).Controls(strControlName) _
= strValueToSet
End If
--
Marsh
MVP [MS Access]


What I want is to effectively 'run' a string, I.e.

myStr= "If (Forms!MyForm.Text1 <> 1) then Forms!MyForm.Text2 = 2"
<run> myStr

I could break the string down into components, e.g.

strFormName = "MyForm"
strControl1 = "Text1"
strControl2 = "Text2"
strValueToSeek = "1"
strValueToSet1 = "2"

..and then use your suggestion..

If Forms(strFormName).Controls(strControl1).Value = strValueToSeek then
Forms(strFormName).Controls(strControlName).Value = strValueToSet

But the user's rule could be <>1 , =1, <1 , >1...........

That's where I am having trouble..

You see, I need my users to be able to add very simple rules into a table,
and then their rules run when the form is closed...


of
a
Click to expand...
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