I have a class in vba called MyClass
Option Explicit
Private msg As String
Public Property Get Message()
Message = msg
End Property
Public Sub Init(ByVal str As String)
msg = str
End Sub
I want to populate collection with objects of that class so to test
Dim items As Collection
Dim Item As MyClass
Set items = New Collection
Set Item = New MyClass
Item.Init "test"
items.Add Item
Item = items.Item(1)
I not really speacilist in scripting i just need to do simple things so i dont understand why is it, but when i run the block above i get error:
Run time error 438 Object' doesn't support this property or method
I checked in the debugger and it happens when i do step over on this line:
Item = items.Item(1)
How do i properly insert class objects to collection and get them back so i can use them without this error?
To be valid, Item must be an object type consistent with the object being assigned to it.
The Dim, Private, Public, ReDim, and Static statements only declare a variable that refers to an object. No actual object is referred to until you use the Set statement to assign a specific object.
So, don't forget to use the Set statement in VBA when you assign an object reference in the code:
Dim items As Collection
Dim Item As MyClass
Set items = New Collection
Set Item = New MyClass
Item.Init "test"
items.Add Item
Set Item = items.Item(1)
Related
I am a novice user of class module.
I don't understand the concept of a class module well.
I want to configure a class module similar to the basic objects of Excel like Worksheet or Cells or ETC..
So I want to control it by creating a parent object and creating its child objects.
Child Class - Defect
Option Explicit
Private pDefectSymptom As String
Private pDefectLevel As Integer
Property Get DefectSymptom() As String
DefectSymptom = pDefectSymptom
End Property
Property Let DefectSymptom(ByVal vDefectSymptom As String)
pDefectSymptom = vDefectSymptom
End Property
Property Get DefectLevel() As Integer
DefectLevel = pDefectLevel
End Property
Property Let DefectLevel(ByVal vDefectLevel As Integer)
pDefectLevel = vDefectLevel
End Property
Function Delete()
'???
End Function
Property Get Parent() As Object
'???
End Property
Parent Class - Defects
Private Defects As New Collection
Function Add(DefectSymptom As String, Optional DefectLevel As Integer) As Defect
Dim NewDefect As Defect
Set NewDefect = New Defect
NewDefect.DefectSymptom = DefectSymptom
NewDefect.DefectLevel = DefectLevel
Defects.Add NewDefect
'Add = NewDefect 'Error! Like the open command of workbook, I want to return an object or just command
End Function
Property Get Count() As Long
Count = Defects.Count
End Property
Property Get Item(Index As Long) As Defect
Item = Defects(Index) 'Error! I don't know what raise Error.
End Property
My question are.
How to add Command like Open Command of workbook. Return or just command.
Why Raise Error Item Property? how to fix that?
Hiding Private variable. Because office office objects seem to be hidden.
enter image description here
If you have time, please help with Delete command and Parent command.
How to add Command like Open Command of workbook. Return or just
command.
You just need to return the newly created object in the function. Keep in mind since we're dealing with objects, we need to Set the object's reference.
Public Function Add(DefectSymptom As String, Optional DefectLevel As Integer) As Defect
Dim NewDefect As Defect
Set NewDefect = New Defect
NewDefect.DefectSymptom = DefectSymptom
NewDefect.DefectLevel = DefectLevel
Defects.Add NewDefect
Set Add = NewDefect '<- here
End Function
Why Raise Error Item Property? how to fix that?
Same as the above, you need to Set the object's reference.
Property Get Item(Index As Long) As Defect
Set Item = Defects(Index)
End Property
To delete, simply supply the index to the function. However, this method must reside where the collection is (parent) since a Defect object cannot delete itself.
Function Delete(ByVal Index As Long)
Defects.Remove Index
End Function
Lastly, to hold a reference to the parent, each child must hold a reference to it in a private variable. Then you need to set the parent when creating a new item using the keyword Me.
So in the Defect class, create a private field.
Private mParent As Defects
Property Set Parent(ByVal objDefects As Defects)
Set mParent = objDefects
End Property
Property Get Parent() As Defects
Set Parent = mParent
End Property
With this done, amend the Add() method to store the reference.
Public Function Add(DefectSymptom As String, Optional DefectLevel As Integer) As Defect
Dim NewDefect As Defect
Set NewDefect = New Defect
NewDefect.DefectSymptom = DefectSymptom
NewDefect.DefectLevel = DefectLevel
Set NewDefect.Parent = Me '<- here
Defects.Add NewDefect
Set Add = NewDefect '<- here
End Function
Not sure this is a good idea though. I tend to avoid circular references altogether, since a child can hold the parent in memory by holding a reference to it. You will need to make sure to clear the reference to the Parent when deleting the item.
Lastly, you should avoid creating the Defects collection like this. Instead, you should make use of the class constructor and destructor.
This method is called automatically when a new class is created:
Private Sub Class_Initialize()
Set Defects = New VBA.Collection
End Sub
This method is called just before the class is destroyed from memory.
Private Sub Class_Terminate()
Set Defects = Nothing
End Sub
I'm writing code to instantiate a form that shows one record in each instance. I have functions to open and close instances using a dictionary but now I need to check whether a record is already opened.
Dictionaries and collections only allow you to store pairs of data (key/item) so created a class with two properties: form object and the opened record id. I store key and this object in a dictionary.
Now I want to check if a record id is already opened so I have to loop trough the dictionary checking the record id (servicioid in code below) property of the item.
Class module:
Private propFormulario As Form
Private propServicioId As Long
Public Property Let FormObj(frmFormObj As Form)
Set propFormulario = frmFormObj
End Property
Public Property Get FormObj() As Form
Set FormObj = propFormulario
End Property
Public Property Let servicioid(lngServicioId As Long)
propServicioId = lngServicioId
End Property
Public Property Get servicioid() As Long
servicioid = propServicioId
End Property
Open and close instances:
Public dicFormServicios As New Dictionary
Public Sub AbrirServicio(lngServicioId As Long)
Dim ServicioAbierto As clsServiciosAbiertos
Set ServicioAbierto = New clsServiciosAbiertos
ServicioAbierto.FormObj = New Form_servicios2
ServicioAbierto.servicioid = lngServicioId
dicFormServicios.Add CStr(ServicioAbierto.FormObj.hwnd), ServicioAbierto
ServicioAbierto.FormObj.visible = True
End Sub
Public Sub CerrarServicio(InstanciaHwnd As Long)
If dicFormServicios.Exists(CStr(InstanciaHwnd)) Then
dicFormServicios.Remove CStr(InstanciaHwnd)
End If
End Sub
My question is how do I loop trough the dictionary and how do I check an ID is in the servicioid property of any item.
My VBA is a bit rusty, so you're going to want to do something along the lines of...
dicFormServicios.Add myForm.FormId, myForm
Then to recover a value try...
myReturnForm = dicFormServicios.Item("SomeFormName")
Details here...
Dictionary Object
Whether a value exists
Recover an item from the dictionary
(The Dictionary reference above is very useful, but really...) All of the objects that you need are already there. You can reference an object directly from the Forms collection using either an index number...
Set myForm = Forms![0]
...or by using the form's name...
Set myForm = Forms!["myFormName"]
(Such a long time since I've done any of this stuff!)
I wanted to first thank you all for the help you've given me implicitly over the last few months! I've gone from not knowing how to access the VBA IDE in Excel to writing fully integrated analysis programs for work. I couldn't have done it without the community here.
I'm currently trying to overhaul the first iteration of a data analysis program I wrote while learning how to code in VBA. While purpose driven and only really legible to myself, the code worked; but was a mess. From folks on this site I picked up Martin's Clean Code and gave it a read on how to try and be a better programmer.
From Martin's Clean Code, it was impressed on me to prioritize abstraction and decoupling of my code to allow for higher degrees of maintenance and modularization. I found this out the hard way since very minor changes requested above my pay grade would require massive and confusing rewrites! I'm trying to eliminate that problem going forward.
I am attempting to rewrite my code in terms of single responsibility classes (at least, where it is possible) and I am a bit confused. I apologize if my question isn't clear or if I'm using the wrong terminology. I want to be able to generate a collection of specific strings (the names of our detectors to be specific) with no duplicates from raw instrument data files from my lab. The purpose of this function is to assemble a bunch of metadata in a class and use it to standardize our file system and prevent clerical errors from newbies and old hands when they use the analysis program.
The testing initialization sub is below. It pops open a userform asking for the user to select the filepaths of the three files in the rawdatafiles class; then it kills the userform to free memory. The metadata object is currently for testing and will be rewritten properly when I get the output I want:
Sub setup()
GrabFiles.Show
Set rawdatafiles = New cRawDataFiles
rawdatafiles.labjobFile = GrabFiles.tboxLabJobFile.value
rawdatafiles.rawdatafirstcount = GrabFiles.tboxOriginal.value
rawdatafiles.rawdatasecondcount = GrabFiles.tboxRecount.value
Set GrabFiles = Nothing
Dim temp As cMetaData
Set temp = New cMetaData
temp.labjobName = rawdatafiles.labjobFile
'this works fine!
temp.detectorsOriginal = rawdatafiles.rawdatafirstcount
' This throws run time error 424: Object Required
End Sub
The cMetadata class I have currently is as follows:
Private pLabjobName As String
Private pDetectorsOriginal As Collection
Private pDetectorsRecheck As Collection
Private Sub class_initialize()
Set pDetectorsOriginal = New Collection
Set pDetectorsRecheck = New Collection
End Sub
Public Property Get labjobName() As String
labjobName = pLabjobName
End Property
Public Property Let labjobName(fileName As String)
Dim FSO As New FileSystemObject
pLabjobName = FSO.GetBaseName(fileName)
Set FSO = Nothing
End Property
Public Property Get detectorsOriginal() As Collection
detectorsOriginal = pDetectorsOriginal
End Property
Public Property Set detectorsOriginal(originalFilepath As Collection)
pDetectorsOriginal = getDetectors(rawdatafiles.rawdatafirstcount)
End Property
When I step through the code it starts reading the "public property get rawdatafirstcount() as string" and throws the error after "End Property" and points back to the "temp.detectorsOriginal = rawdatafiles.rawdatafirstcount" line in the initialization sub.
I think I'm at least close because the temp.labjobName = rawdatafiles.labjobFile code executes properly. I've tried playing around with the data types since this is a collection being assigned by a string but I unsurprisingly get data type errors and can't seem to figure out how to proceed.
If everything worked the way I want it to, the following function would take the filepath string from the rawdatafiles.rawdatafirstcount property and return for me a collection containing detector names as strings with no duplicates (I don't know if this function works exactly the way I want since I haven't been able to get the filepath I want to parse properly in the initial sub; but I can deal that later!):
Function getDetectors(filePath As String) As Collection
Dim i As Integer
Dim detectorsCollection As Collection
Dim OriginalRawData As Workbook
Set OriginalRawData = Workbooks.Open(fileName:=filePath, ReadOnly:=True)
Set detectorsCollection = New Collection
For i = 1 To OriginalRawData.Worksheets(1).Range("D" & Rows.Count).End(xlUp).Row
detectorsCollection.Add OriginalRawData.Worksheets(1).Cells(i, 4).value, CStr(OriginalRawData.Worksheets(1).Cells(i, 4).value)
On Error GoTo 0
Next i
getDetectors = detectorsCollection
Set detectorsCollection = Nothing
Set OriginalRawData = Nothing
End Function
Thanks again for reading and any help you can offer!
temp.detectorsOriginal = rawdatafiles.rawdatafirstcount
' This throws run time error 424: Object Required
It throws an error because, as others have already stated, the Set keyword is missing.
Now with that out of the way, a Set keyword is NOT what you want here. In fact, sticking a Set keyword in front of that assignment will only buy you another error.
Let's look at this property you're invoking:
Public Property Get detectorsOriginal() As Collection
detectorsOriginal = pDetectorsOriginal
End Property
Public Property Set detectorsOriginal(originalFilepath As Collection)
pDetectorsOriginal = getDetectors(rawdatafiles.rawdatafirstcount)
End Property
You're trying to assign detectorsOriginal with what appears to be some String value that lives in some TextBox control on that form you're showing - but the property's type is Collection, which is an object type - and that's not a String!
Now look at the property that does work:
Public Property Get labjobName() As String
labjobName = pLabjobName
End Property
Public Property Let labjobName(fileName As String)
Dim FSO As New FileSystemObject
pLabjobName = FSO.GetBaseName(fileName)
Set FSO = Nothing
End Property
This one is a String property, with a Property Let mutator that uses the fileName parameter it's given.
The broken one:
Public Property Set detectorsOriginal(originalFilepath As Collection)
pDetectorsOriginal = getDetectors(rawdatafiles.rawdatafirstcount)
End Property
Is a Set mutator, takes a Collection parameter, and doesn't use the originalFilepath parameter it's given at all!
And this is where I'm confused about your intention: you're passing what has all the looks of a String except for its type (Collection) - the calling code wants to give it a String.
In other words the calling code is expecting this:
Public Property Let detectorsOriginal(ByVal originalFilepath As String)
See, I don't know what you meant to be doing here; it appears you're missing some pOriginalFilepath As String private field, and then detectorsOriginal would be some get-only property that returns some collection:
Private pOriginalFilePath As String
Public Property Get OriginalFilePath() As String
OriginalFilePath = pOriginalFilePath
End Property
Public Property Let OriginalFilePath(ByVal value As String)
pOriginalFilePath = value
End Property
I don't know what you're trying to achieve, but I can tell you this:
Don't make a Property Set member that ignores its parameter, it's terribly confusing code.
Don't make a Property (Get/Let/Set) member that does anything non-trivial. If it's not trivially simple and has a greater-than-zero chance of throwing an error, it probably shouldn't be a property. Make it a method (Sub, or Function if it needs to return a value) instead.
A word about this:
Dim FSO As New FileSystemObject
pLabjobName = FSO.GetBaseName(fileName)
Set FSO = Nothing
Whenever you Dim something As New, VBA will automatically instantiate the object whenever it's referred to. In other words, this wouldn't throw any errors:
Dim FSO As New FileSystemObject
Set FSO = Nothing
pLabjobName = FSO.GetBaseName(fileName)
Avoid As New if you can. In this case you don't even need a local variable - use a With block instead:
With New FileSystemObject
pLabjobName = .GetBaseName(fileName)
End With
May not be your issue but you're missing Set in your detectorsOriginal Set/Get methods:
Public Property Get detectorsOriginal() As Collection
Set detectorsOriginal = pDetectorsOriginal
End Property
Public Property Set detectorsOriginal(originalFilepath As Collection)
Set pDetectorsOriginal = getDetectors(rawdatafiles.rawdatafirstcount)
End Property
So the error is one I've made a time or two (or more). Whenever you assign an object to another object, you have to use the Set reserved word to assign the reference to the Object.
In your code do the following:
In Sub setup()
Set temp.detectorsOriginal = rawdatafiles.rawdatafirstcount
And in the cMetadata class change the Public Property Set detectorsOriginal(originalFilepath As Collection) property to the following:
Public Property Get detectorsOriginal() As Collection
Set detectorsOriginal = pDetectorsOriginal
End Property
Public Property Set detectorsOriginal(originalFilepath As Collection)
Set pDetectorsOriginal = getDetectors(rawdatafiles.rawdatafirstcount)
End Property
Also in your function Function getDetectors(filePath as String) as Collection change the statement afterNext i` to
Set getDetectors = detectorsCollection
Also, I'm very glad to hear that you've learned how to use VBA.
When you're ready to create your own Custom Collections, check out this post. Your own custom Collections.
I also book marked Paul Kelly's Excel Macro Mastery VBA Class Modules – The Ultimate Guide as well as his Excel VBA Dictionary – A Complete Guide.
If you haven't been to Chip Pearson's site you should do so. He has a ton of useful code that will help your delivery your projects more quickly.
Happy Coding.
I'm currently trying to build a collection of items wherein a collection might contain an another collection as an Item within.
I've set two collections and created a class module for each:
col1 - (linked to Class1); and col2 - (linked to Class2)
Below are my Class Modules:
Class1:
Option Explicit
Private pTestC1A As String
Private pTestC1B As Collection
Public Property Let TestC1A(Value As String)
pTestC1A = Value
End Property
Public Property Get TestC1A() As String
TestC1A = pTestC1A
End Property
Property Set TestC1B(col2 As Collection)
Set pTestC1B = col2
End Property
Property Get TestC1BElements(v As Integer) As String
TestC1B = pTestC1B(v)
End Property
Class2:
Option Explicit
Private pTestC2A As String
Public Property Let TestC2A(Value As String)
pTestC2A = Value
End Property
Public Property Get TestC2A() As String
TestC2A = pTestC2A
End Property
Below is my Module code
Sub Test()
Set col1 = New Collection
Set col2 = New Collection
Set cV = New Class1
cV.TestC1A = "First Collection"
Set aV = New Class2
aV.TestC2A = "Second Collection"
sKey1 = CStr(aV.TestC2A)
col2.Add aV, sKey1
Set cV.TestC1B = col2
sKey2 = CStr(cV.TestC1A)
col1.Add cV, sKey2
If Err.Number = 457 Then
MsgBox "Error Occured"
ElseIf Err.Number <> 0 Then Stop
End If
Err.Clear
Msgbox col1(1).TestC1A ' works fine
Msgbox col2(1).TestC2A ' works file
MsgBox col1(1).TestC1B(1).TestC2A ' does not work - 450 run-time error
End Sub
As per the above code, I'm successfully able to get the values of the items if I reference each collection respectively, however I'm getting a "Wrong number of arguments or invalid property assignment" run-time error if I try to get the item value in a nested fashion.
It would be appreciated if someone can help point out where I'm going wrong, and perhaps shed some light on the way the class module handles the Property Set & Get parameters for a collection.
You are missing a Get TestC1B property in your Class1 class module:
Property Get TestC1B() As Collection
Set TestC1B = pTestC1B
End Property
Once that is present you will be able to make calls to col1(1).TestC1B(1) and access it's .TestC2A property
Background
You did the right thing by using private variables in your classes and using properties to give read/write access to your private variables. You'll get a lot more control this way.
Property Get gives read access to that property (and broadly speaking, the underlying private variable). For example you can use Range.Address to return (read) the address of a range object.
Property Let and Set give write access to the property. Use Set for objects. For example Range.Value = 1 will write the new value to the range.
Consider, Range.Address = $A$1. Since there is no Property Set for the address of a range, this will not change the address of the range. It will consider the Range.Address part a Get call and evaluate something like $A$1 = $A$1 returning TRUE in this example
I have an array of objects in an excel vba project. I have created another instance of the same class and set 1 of its properties. I am then trying to search through the array of objects to find the object in the array that matches the current one on the same property. I would like to set the current object to the one in the array inside one of the current object's methods using the self reference Me.
I tried:
Set Me = objectArray(index)
This does not work. It says that this is an improper use of the Me keyword. Is there a way to set the current object to another object of the same type? Thanks!
Edit:
I have an object that has child objects:
Me.friShift.shiftType.loadFromArray
Here, shiftType is the object of type CVocabulary, which is my self defined class. It has a sub called loadFromArray that looks like this:
Public Sub loadFromArray()
Dim index As Integer
index = searchVocabArray(Me.typed)
If (index = -1) Then
Exit Sub
End If
Set Me = vocabArray(index)
End Sub
vocabArray() is a global array containing CVocabulary objects.
If it is not possible to Set an object from within itself, I can try something else. This is just the easiest and most direct way of doing this. I'm sure I can just set each parameter from the current object to the value of the parameter from the object in the array, but if it was possible to do something like the above, that would have been my preferred method.
You can do it by giving itself to the function as a parameter. I'll show it in VBScript because the classes are more clear, but the concept is the same as in VBA:
public myObject
set myObject = new x
myObject.ChangeMe MyObject
msgbox typename(myObject) ' <- outputs 'y'
class x
public sub changeMe(byref object)
set object = new y
end sub
end class
class y
' just an empty class
end class
But this is not a good programming pattern and could cause messy code (maintenance and debugging would be an issue) and even memory leaks. You should create an (Abstract) Factory, Builder or Provider that returns an object as you ask for it.
Factory: creates a new predefined object
Builder: creates a new object that is configured in the builder
Provider: returns an existing object that is predefined earlier
I don't beleive you can use Me in this context - you are trying to use Me as it was used in VB6 (which was equivalent to 'this' in C#). This is not appropriate in VBA.
Without some code snippets its hard to see what you are doing. Can you perform the search in a module and create instances of this class there? You can then do:
Set class2 = objectArrayofClass1(index)
As you've already seen that Me cannot be changed. You can handle memorized objects through
a function in a public Module like basExternal:
Public Function loadFromArrayByIndex(ByVal lIndex)
dim xobj as Object
Set xobj = vocabArray(lIndex)
'
' do modifications and handling on this object:
' ...
'
End Function
.