I have this module here that has is Workbook subroutine. I can't for the life of me understand how the GenerateLimitSummary is ever able to run? Can someone please articulate the process flow here?
Private LimitBool As Boolean
Private Sub Workbook_SheetCalculate(ByVal Sh As Object)
If LimitBool Then Exit Sub
' use conditional formatting to highlight limit breaches
ApplyConditionalFormatting
' regenerate the summary limits sheet
LimitBool = True
GenerateLimitSummary
LimitBool = False
End Sub
The author uses LimitBool to prevent a infinite loop/a stack overflow:
Initially, LimitBool is False, therefore the remainder of Workbook_SheetCalculateis executed
Now, LimitBool is set to True (after it was confirmed it's not True)
GenerateLimitSummary is executed. If this routine now for some reasons forces the workbook to recalculate, Workbook_SheetCalculate will be triggered again. However, as LimitBool is now True*, the second call to this procedure is now Exited after the first check. If it would not have this check, it would again call GenerateLimitSummary, which would then trigger the recalc, etc...
After the GenerateLimitSummaryran, LimitBool is set back to False, therefore, it can ran again
(*) - it has a Module-wide scope, i.e. it keeps it value across the different calls, while a procedure-wide scope (=Dimmed in the sub) would create a new variable for each call
Related
Anyone else finding that their Terminate() method in Access isn't being called?
Here's my code for my cBusyPointer class with the comments removed for brevity:
Option Compare Database ' Use database order for string comparisons
Option Explicit ' Declare EVERYTHING!
Option Base 1 ' Arrays start at 1
Public Sub show()
DoCmd.hourGlass True
End Sub
Private Sub Class_Terminate()
DoCmd.hourGlass False
End Sub
Typical usage is:
Sub doTehThings()
Dim hourGlass As New cBusyPointer
hourGlass.show()
' Do all teh things
End Sub
In previous versions, this class would restore the hourglass whenever the object went out of scope and was destroyed.
I even tried to manually destroy my hourglass object:
Sub doTehThings()
Dim hourGlass As cBusyPointer
Set hourGlass = New cBusyPointer
hourGlass.show()
' Do all teh things
Set hourGlass = Nothing
End Sub
The only way to fix this is to add a hide() method and call that.
Has anyone else encountered this problem?
I cannot replicate the issue. The Terminate() method is called upon reaching the Set hourGlass = Nothing.
A couple of points:
Dim hourGlass As New cBusyPointer
This will create a new instance every time you call the hourGlass variable even to set it to Nothing. See the answer in the link below for additional info:
What's the difference between Dim As New vs Dim / Set
You should always use Dim/Set when working with objects.
hourGlass.show()
This does not even compile in VBA. Subs do not accept parentheses even when arguments are being expected, unless they are preceded with the Call keyword.
Lastly, the cleanest way to reference an object is to access it using the With statement which ensures the object is terminated when the End With statement is reached.
With New cBusyPointer
.show
End With
I have a userform which contains a TextBox object named myTextBox.
The text inside the object can be changed either by the user or by the code. There's a "onChange" procedures attached to the textbox:
Private Sub myTextBox_Change()
'do some stuffs
End Sub
I would like the event to be processed only when is the user changing the text, but not the code. I had thought about adding an Optional parameter like the following:
Private Sub myTextBox_Change(Optional isCode As Boolean)
If isCode = False Then
'do some stuffs
End If
End Sub
but this is not really helpful because I cannot pass the isCode = True when changing the name programmatically, like this:
myForm.myTextBox = "new text"
Does anyone have an idea on how I can fix this?
One way (perhaps not the right way?) would be to declare a global variable to use in the same way as your IsCode Boolean. Set it to true during your code block so the textbox_change event knows code is processing in the background, and then set back to false when that code has finished.
Put this at the top of a normal module (won't work in a form module)
Option Compare Database
Option Explicit
Global IsCode As Boolean
and then in the code you're running just set IsCode=true as required.
Is there some VBA best practice to use something like 'before end' subroutines?
I am changing Excel's default configs when my macro starts, and before my macro reaches its 'end sub' line I am resetting the configs to its standards.
But what if some error occurs? Am I supposed to define 'On Error' treatment inside all subs to reset the configs to the standard properties?
Just for example, I am changing configs such as:
ScreenUpdating
DisplayStatusBar
Calculation
DisplayAlerts
I'm pretty sure there is no such mechanism that is called unconditionally before exiting a function or a subroutine. You may have though error handlers (but these are executed conditionally; see the comment of ckuhn203 for an example).
However, there is such a mechanism for instances of Class Modules (i.e. for objects). When an object is destroyed (this happens when is not referenced anymore by any variable/storage), its Class_Terminate subroutine is called no-matter-what. If you can wrap your task in such an object that you discard immediately after you create it, you could override overwrite this subroutine to do the cleanup.
If I understand your question correctly, yes, the best way is to define an On Error Goto line, in each method where it's needed, like this:
Public Sub DoSomething()
On Error GoTo Finally ' Try
Application.ScreenUpdating = False
' Do your stuff here
Finally:
Application.ScreenUpdating = True
End Sub
This will ensure the things like ScreenUpdating get done even if there is an error. You can also add a catch block, like this:
Public Sub DoSomething()
On Error GoTo Catch ' Try
Application.ScreenUpdating = False
' Do normal stuff here
GoTo Finally
Catch:
' Do only error stuff here
Finally:
Application.ScreenUpdating = True
End Sub
Generally speaking, GoTo is a hated practice, but for error catching, VBA kind of forces your hand.
I am developing an Excel (2010+) Application using VBA and have run into an issue where the AfterRefresh event function is not being invoked once the query finishes executing.
I have not been able to find many decent resources or documentation for how to have this event function triggered in a Class Module. I decided to use the Class Module design route instead of putting the event handlers in the worksheet after receiving a response to an earlier question about QueryTables (found here Excel VBA AfterRefresh).
Here is the code for my Class Module called CQtEvents
Option Explicit
Private WithEvents mQryTble As Excel.QueryTable
Private msOldSql As String
' Properties
Public Property Set QryTble(ByVal QryTable As QueryTable): Set mQryTble = QryTable:
End Property
Public Property Get QryTble() As QueryTable: Set QryTble = mQryTble:
End Property
Public Property Let OldSql(ByVal sOldSql As String): msOldSql = sOldSql:
End Property
Public Property Get OldSql() As String: OldSql = msOldSql:
End Property
Private Sub Class_Initialize()
MsgBox "CQtEvents init"
End Sub
' Resets the query sql to the original unmodified sql statement
' This method is invoked when the Refresh thread finishes executing
Private Sub mQryTble_AfterRefresh(ByVal Success As Boolean)
' Problem is here
' This function is never called :( Even if the query successfully runs
Me.QryTble.CommandText = Me.OldSql
End Sub
Here is a quick snapshot of the code the creates an instance of this class, finds a relevant QueryTable, then calls Refresh
Option Explicit
Sub RefreshDataQuery()
'Dependencies: Microsoft Scripting Runtime (Tools->References) for Dictionary (HashTable) object
'From MGLOBALS
cacheSheetName = "Cache"
Set cacheSheet = Worksheets(cacheSheetName)
Dim querySheet As Worksheet
Dim interface As Worksheet
Dim classQtEvents As CQtEvents
Set querySheet = Worksheets("QTable")
Set interface = Worksheets("Interface")
Set classQtEvents = New CQtEvents
Dim qt As QueryTable
Dim qtDict As New Scripting.Dictionary
Set qtDict = UtilFunctions.CollectAllQueryTablesToDict
Set qt = qtDict.Item("Query from fred2")
''' Building SQL Query String '''
Dim sqlQueryString As String
sqlQueryString = qt.CommandText
Set classQtEvents.QryTble = qt
classQtEvents.OldSql = sqlQueryString ' Cache the original query string
QueryBuilder.BuildSQLQueryStringFromInterface interface, sqlQueryString
' Test message
MsgBox sqlQueryString
qt.CommandText = sqlQueryString
If Not qt Is Nothing Then
qt.Refresh
Else
' ... Error handling code here...
End If
''' CLEAN UP '''
' Free the dictionary
Set qtDict = Nothing
End Sub
Also here is a screenshot of the Module structure http://imgur.com/8fUcfLV
My first thought on what might be the issue was passing the QueryTable by value. I am not the most experienced VBA developer, but I reasoned this would create a copy and be calling the event on an unrelated table. However, this was not the case and passing by Reference did not fix the problem either.
Also the query is confirmed to run successfully as the data is correctly showing up and being refreshed.
EDIT
I added the BeforeRefresh event function to CQtEvents class Module and confirmed this function is called once Refresh is called
Private Sub mQryTble_BeforeRefresh(Cancel As Boolean)
MsgBox "Start of BeforeRefresh"
End Sub
How might I alter this code get my QueryTable from the QTableModule's RefreshDataQuery() Sub routine to have the AfterRefresh function invoked when the query is successfully ran?
How to catch the AfterRefresh event of QueryTable?
Explanation: in your situation, before event was fired you lost reference of your QueryTable by setting it to nothing when you made cleaning or procedure ended.
General solution: you must be sure that your code is still running and/or you need to keep any references to your QueryTable.
1st solution. When calling QT.Refresh method set the parameter to false in this way:
qt.Refresh false
which will stop further code execution until your qt is refreshed. But I don't consider this solution to be the best one.
2nd solution. Make your classQtEvents variable public and after RefreshDataQuery sub is finished check the status with some other code.
in you CQtEvents class module add the following public variable:
Public Refreshed As Boolean
in your BeforeRefresh event add this:
Refreshed = False
in your AfterRefresh event add this line of code:
Refreshed = True
Make your classQtEvents variable declaration public. Put this before Sub RefreshDataQuery()
Public classQtEvents as CQtEvents
but remove appropriate declaration from within your sub.
Now, even your sub is finished you will be able to check status of refreshment by checking .Refreshed property. You could do it in Immediate or within other Sub. This should work for Immediate:
Debug.Print classQtEvents.Refreshed
3rd solution. (a bit similar to 1st one) Follow steps 1 to 3 from 2nd solution. After you call qt.Refresh method you could add this loop which will stop further code execution until qt is refreshed:
'your code
If Not qt Is Nothing Then
qt.Refresh
Else
' ... Error handling code here...
End If
'checking
Do Until classQtEvents.Refreshed
DoEvents
Loop
Final remark. I hope I didn't mixed up qt variable with classQtEvents variable. I didn't tried and tested any solution using your variables but wrote all above with referenced to code I use.
A github repo that demonstrates the minimum code needed to get this working can be found here.
As mentioned, if your event handler isn't in scope, or your QueryTable reference is lost, you won't catch the event. The key factors to ensuring you catch the event are:
Declare a global variable of your event-handling class module's type outside of any subroutines/methods, at the top of a file (I chose the ThisWorkbook file).
Add a Workbook_Open event handler and instantiate that variable there, so that it is available immediately and will remain in scope (since it's global).
At that point, or at any downstream point when you have a QueryTable you're interested in, pass that QueryTable to the global instance to wire up its events.
(It took me a couple tries to figure this out myself, when someone pointed me in this direction as an answer to this question.)
Objective: Redirect focus from one command button to another using the first's GotFocus procedure.
Context: I have a form-independent procedure in a generic module that, on most forms, sets focus to the NewRecord button after saving the previous record. But on one form, I would like to redirect (based on certain conditions) focus back to the SignRecord button so the user can "sign" a second part of the same record (I may need this for other uses in the future). The target control is enabled and visible and can otherwise be focused and the original control can be focused when the redirect doesn't occur. Reference [2] below implies that this should be possible, though I'm not changing visibility of my controls.
Issue: When the conditions are met to redirect focus in the GotFocus procedure, it redirects as desired but the original (test) SetFocus call throws a "Run-time error '2110', Can't move focus to the control CommandNew".
What I've tried:
Exit Sub after my downstream SetFocus calls.
Call CommandSign.SetFocus in the hopes that it would make it happen outside the previous SetFocus process.
In a module,
Public Sub test()
Forms("TargetForm").CommandNew.SetFocus 'This gets the error '2110'
End Sub
In the 'TargetForm',
Private Sub CommandNew_GotFocus()
If IsNull(textDateTime) Then Exit Sub 'Works as expected
'I can see these two parts work. The framSign value changes
'and CommandSign gets focus
If checPPC And IsNull(textSigID_PPC) And framSign = 2 Then
framSign = 1
CommandSign.SetFocus
ElseIf checDAS And IsNull(textSigID_DAS) And framSign = 1 Then
framSign = 2
CommandSign.SetFocus
End If
End Sub
References:
[1]: SelectNextControl() a bad idea in a GotFocus event?
[2]: http://www.access-programmers.co.uk/forums/showthread.php?t=100071
I think your problem is that the call to Forms("TargetForm").CommandNew.SetFocus doesn't quite seem to, in fact, finish setting the focus to CommandNew until after Private Sub CommandNew_GotFocus() has finished executing. Because you've called another SetFocus before the first SetFocus could finish, there is a conflict that Access seems to be unable to cope with.
Whether or not that is the case, one thing is clear: the way you have your execution plan set up right now is unfortunately not going to work. You might try adding either a global variable or a public variable to each form that determines whether or not you should set your focus to CommandSign after you set the focus to CommandNew.
Ex. TargetForm:
Public boolSetCommandSignFocusInstead As Boolean
Private Sub CommandNew_GotFocus()
If IsNull(textDateTime) Then Exit Sub 'Works as expected
'I can see these two parts work. The framSign value changes
'and CommandSign gets focus
If checPPC And IsNull(textSigID_PPC) And framSign = 2 Then
framSign = 1
boolSetCommandSignFocusInstead = True
ElseIf checDAS And IsNull(textSigID_DAS) And framSign = 1 Then
framSign = 2
boolSetCommandSignFocusInstead = True
Else
boolSetCommandSignFocusInstead = False
End If
End Sub
Module:
Public Sub test()
Forms("TargetForm").CommandNew.SetFocus
If Forms("TargetForm").boolSetCommandSignFocusInstead Then
Forms("TargetForm").CommandSign.SetFocus
End If
End Sub