Function if form isloaded as form or as a subform (1 Viewer)

[MsAccessNL]

Going back to post #1, you wrote:


To check if a form is loaded, you can use:

?CurrentProject.AllForms("YourFormName").IsLoaded

True if loaded, otherwise false

Or here is alternative code for this as a function:

Function IsFormLoaded(ByVal strFormName As String) As Integer
'Returns a 0 if form is not open or a -1 if Open

On Error GoTo Err_Handler

    If SysCmd(acSysCmdGetObjectState, acForm, strFormName) <> 0 Then
        If Forms(strFormName).CurrentView <> 0 Then
            IsFormLoaded = True
        End If
    End If
  
Exit_Handler:
    Exit Function

Err_Handler:
    MsgBox "Error " & err & " in IsFormLoaded procedure : " & Err.Description
    Resume Exit_Handler
  
End Function

Typical usage: IsFormLoaded("YourFormName")

Code to test whether a form is open as a subform:

Private Function IsSubform() As Boolean
   Dim bHasParent As Boolean

   On Error GoTo Err_Handler

   ' If opened not as a subform, accessing
   ' the Parent property raises an error:
   bHasParent = Not (Me.Parent Is Nothing)

   IsSubform = True
   Exit Function

Err_Handler:
   IsSubform = False
End Function

For example, I use that code as a check in automatic form resizing to resize when opened as a form but not when opened as a subform

Private Sub Form_Load()

    If Not IsSubform Then
        ReSizeForm Me
        Me.NavigationButtons = True
    End If
End Sub

EDIT: I've just noticed the IsSubform code in post #2. Sorry I only skimmed the thread

Wow, your code is so much shorter then mine. This is Exactly what I was asking for in my post . Thnx.

 

[MsAccessNL]

Thnx everybody, this post is solved.

 

[isladogs]

Wow, your code is so much shorter then mine. This is Exactly what I was asking for in my post . Thnx.

You're welcome

 

[Pat Hartman]

 

[MajP]

a (short) function that checkes if a form isloaded as a form and also if it's loaded as a subform.

Not sure what you really mean. I interpret that to simply mean you want code to determine if a form is loaded as a subform not if it is loaded both as a main form and also as a subform.

Isladogs showed how to show if a form is loaded as a main form.

Function IsFormLoaded(ByVal strFormName As String) As Integer
'Returns a 0 if form is not open or a -1 if Open

On Error GoTo Err_Handler

    If SysCmd(acSysCmdGetObjectState, acForm, strFormName) <> 0 Then
        If Forms(strFormName).CurrentView <> 0 Then
            IsFormLoaded = True
        End If
    End If
 
Exit_Handler:
    Exit Function

Err_Handler:
    MsgBox "Error " & err & " in IsFormLoaded procedure : " & Err.Description
    Resume Exit_Handler
 
End Function

To see if a form is loaded as a subform

Public Function IsSubFormLoaded(ByVal strFormName As String) As Boolean
  Dim sFrm As Access.Form
  Dim ctrl As Access.Control
  For Each sFrm In Forms
    For Each ctrl In sFrm.Controls
      If ctrl.ControlType = acSubform Then
        If ctrl.Form.Name = strFormName Then
          IsSubFormLoaded = True
          Exit Function
        End If
      End If
    Next ctrl
  Next sFrm
End Function

If you really want to know if it is loaded as either a main form or a subform, then wrap those functions

Public Function isFormOrSubFormLoaded(ByVal strFormName As String) As Boolean
  If IsFormLoaded(strFormName) Or IsSubFormLoaded(strFormName) Then isFormOrSubFormLoaded = True
End Function

 

[arnelgp]

solved?
but the title is asking if the form is "Loaded" (meaning not a subform) or a subform.
i have a sample db, but much longer than your code.
it will test (on my case, Form1 (see test sub on module1)) the form's status.

possible results:

"Not exists" (if the specified form name does not exists in the db).
"Not loaded" (the form exists but not Open (not in design view), or not a subform).
"Loaded" (if the form is open (normal view) and not a subform)
"Subform" (when the form is a subform)
"SubSubform (prefix "Sub" is repeating, when it is x many times deep embed as subform)

i don't know if anybody can find this useful?

 

[isladogs]

Perhaps I'm missing the point but discussion in this thread seems very convoluted

A form object can be opened as a form or as a subform (or it can be a subreport)
However, for a form object to be detected as e.g. a subform, it must be loaded (open).

Is there some point of significance that I'm overlooking?

 

[Uncle Gizmo]

However, for a form object to be detected as e.g. a subform, it must be loaded (open).

I suspect a subform isn't loaded in the way a normal form is, as it is an instance of the form contained in a subform/subreport control.

However if the so-called "subform" is opened independently it is no longer a subform, it's just an ordinary form and can be detected.

To reiterate the op's question in the hope of clarifying the situation, he found some code which would tell him if a form was open. He discovered that it didn't identify subforms as being open.

He suggested that finding the subforms parent would indicate if it was subform.

Another approach would be to find all of the subform/subreport controls and see what the source object name is. Check that against the collection of forms.

 

[Efer]

I suspect a subform isn't loaded in the way a normal form is, as it is an instance of the form contained in a subform/subreport control.

However if the so-called "subform" is opened independently it is no longer a subform, it's just an ordinary form and can be detected.

To reiterate the op's question in the hope of clarifying the situation, he found some code which would tell him if a form was open. He discovered that it didn't identify subforms as being open.

He suggested that finding the subforms parent would indicate if it was subform.

Another approach would be to find all of the subform/subreport controls and see what the source object name is. Check that against the collection of forms.

Public Function IsLoaded(Search As String, Optional Scan As Object) As Boolean
    Dim i As Object
    Dim First As Boolean
    If Scan Is Nothing Then First = True: Set Scan = Application.Forms
    For Each i In Scan
        If Not First Then
            If i.ControlType = 112 Then
                If Search = i(0).Parent.Name Then IsLoaded = True: Exit Function
                IsLoaded = IsLoaded(Search, i(0).Parent)
                If IsLoaded Then Exit Function
            End If
        Else
            If Search = i.Name Then IsLoaded = True: Exit Function
            IsLoaded = IsLoaded(Search, i)
            If IsLoaded Then Exit Function
        End If
    Next
End Function

 

[ebs17]

@MsAccessNL wrote

I was looking for a (short) function that checkes if a form isloaded as a form and also if it's loaded as a subform.

In the whole discussion and in the presented solutions it has not yet been considered that one can work with several instances of the same form at the same time - and that is anything but confusing if I already have a good and universally usable form.
There can be different design options for these different instances:

- Multiple instances as main form (input form versus data display form)

- Use as a main form and as a subform of another form

- Use as a multiple subform with different data displays in the same main form

If there are several instances, addressing the form by name is not an option. For targeted work, addressing by reference is necessary. It's also important to note that a form is a class and its instance must be able to determine for itself what it is, where it resides, and what it's called as a control, to perform specific actions or not to execute.

With that in mind, I've added something to the DB file of @arnelgp to allow for easy testing.
The simple function:

' sample call
Private Sub Form_Open(Cancel As Integer)
    Dim SourceObjectName As String
    Dim ParentFormName As String
    Dim UFoControlName As String

    Debug.Print
    Debug.Print "Is SubForm: " & IsSubform(Me, SourceObjectName, ParentFormName, UFoControlName)
    Debug.Print "SourceObjectName: " & SourceObjectName, _
                "ParentFormName: " & ParentFormName, _
                "UFoControlName: " & UFoControlName
End Sub

Public Function IsSubform(AnyForm As Access.Form, _
                          Optional ByRef SourceObjectName As String, _
                          Optional ByRef ParentFormName As String, _
                          Optional ByRef UFoControlName As String) As Boolean
    SourceObjectName = AnyForm.Name
    If SysCmd(acSysCmdGetObjectState, acForm, AnyForm.Name) = 0 Then
        IsSubform = True
        ParentFormName = AnyForm.Parent.Name
        UFoControlName = SubformControlName(AnyForm)
    Else
        IsSubform = False
    End If
End Function

Public Function SubformControlName(SubformOBJ As Access.Form) As String
    Dim ctl As Access.Control
   
    For Each ctl In SubformOBJ.Parent
        If ctl.ControlType = acSubform Then
            If ctl.SourceObject = SubformOBJ.Name Then
                If ctl.Form.Hwnd = SubformOBJ.Hwnd Then
                    SubformControlName = ctl.Name
                    Exit For
                End If
            End If
        End If
    Next
End Function

 

[Efer]

@MsAccessNL wrote

In the whole discussion and in the presented solutions it has not yet been considered that one can work with several instances of the same form at the same time - and that is anything but confusing if I already have a good and universally usable form.
There can be different design options for these different instances:

- Multiple instances as main form (input form versus data display form)

- Use as a main form and as a subform of another form

- Use as a multiple subform with different data displays in the same main form

If there are several instances, addressing the form by name is not an option. For targeted work, addressing by reference is necessary. It's also important to note that a form is a class and its instance must be able to determine for itself what it is, where it resides, and what it's called as a control, to perform specific actions or not to execute.

With that in mind, I've added something to the DB file of @arnelgp to allow for easy testing.
The simple function:

' sample call
Private Sub Form_Open(Cancel As Integer)
    Dim SourceObjectName As String
    Dim ParentFormName As String
    Dim UFoControlName As String

    Debug.Print
    Debug.Print "Is SubForm: " & IsSubform(Me, SourceObjectName, ParentFormName, UFoControlName)
    Debug.Print "SourceObjectName: " & SourceObjectName, _
                "ParentFormName: " & ParentFormName, _
                "UFoControlName: " & UFoControlName
End Sub

Public Function IsSubform(AnyForm As Access.Form, _
                          Optional ByRef SourceObjectName As String, _
                          Optional ByRef ParentFormName As String, _
                          Optional ByRef UFoControlName As String) As Boolean
    SourceObjectName = AnyForm.Name
    If SysCmd(acSysCmdGetObjectState, acForm, AnyForm.Name) = 0 Then
        IsSubform = True
        ParentFormName = AnyForm.Parent.Name
        UFoControlName = SubformControlName(AnyForm)
    Else
        IsSubform = False
    End If
End Function

Public Function SubformControlName(SubformOBJ As Access.Form) As String
    Dim ctl As Access.Control
  
    For Each ctl In SubformOBJ.Parent
        If ctl.ControlType = acSubform Then
            If ctl.SourceObject = SubformOBJ.Name Then
                If ctl.Form.Hwnd = SubformOBJ.Hwnd Then
                    SubformControlName = ctl.Name
                    Exit For
                End If
            End If
        End If
    Next
End Function

Public Function IsLoaded(Search As String, Optional Scan As Object) As Boolean
    Dim i As Object
    Dim First As Boolean
    If Scan Is Nothing Then First = True: Set Scan = Application.Forms
    For Each i In Scan
        If Not First Then
            If i.ControlType = 112 Then
                If Search = i(0).Parent.Name Then IsLoaded = True: Exit Function
                IsLoaded = IsLoaded(Search, i(0).Parent)
                If IsLoaded Then Exit Function
            End If
        Else
            If Search = i.Name Then IsLoaded = True: Exit Function
            IsLoaded = IsLoaded(Search, i)
            If IsLoaded Then Exit Function
        End If
    Next
End Function

 

[isladogs]

How many versions of code to detect a subform do we really need in this thread?
I gave code to detect if a form is open as a subform in post #20, then realised @cheekybuddha had given similar code in post #2

It seems to me that we are going around in circles...or am I still missing something?

 

[ebs17]

@Efer and @isladogs, I have introduced and formulated an extension of requirements, which is also relevant to practice, at least in a better practice.

If a form instance is to check and recognize itself, questions as to whether the instance is loaded or whether the form even exists have long been answered and therefore do not need to be asked again.
So my answer is quite different from yours or any previous one. Let's see if anyone recognizes this on their own.

 

[KitaYama]

Let's see if anyone recognizes this on their own.

Now we are offering puzzles instead of solving problems.
It's at least your second try to offer a code and say go figure yourself what it does.
It was your answer to @Pat Hartman here

If you don't understand the hint, then ignore it.

 

[ebs17]

Now we are offering puzzles instead of solving problems.

Do I have to be surprised if a description as text plus a complete open code plus a demo DB appears as a puzzle to a viewer who perceives this as a whole?

Access User Group – Europe

The video of Alan Cossey's excellent presentation to last week's Access Europe meeting is now available on YouTube: The Standard Module Object Generation (SMOG) add-in and supporting files are also now available free to all Access Europe subscribers from...

www.access-programmers.co.uk

The simultaneous use of multiple instances of the same form is familiar to some.

 

[KitaYama]

Do I have to be surprised if a description as text plus a complete open code plus a demo DB appears as a puzzle to a viewer who perceives this as a whole?

Access User Group – Europe

The video of Alan Cossey's excellent presentation to last week's Access Europe meeting is now available on YouTube: The Standard Module Object Generation (SMOG) add-in and supporting files are also now available free to all Access Europe subscribers from...

www.access-programmers.co.uk

The simultaneous use of multiple instances of the same form is familiar to some.

@ebs17 My English is not that good, so I really can't understand what you mean by that. Maybe if I watch the video and read the linked you sent I can find a relation between my comment, your reply and the contents, but for now, I'm terribly busy with my job.

My apologies.