List object methods and properties
Using TypeLib Information Objects from tlbinf32.dll it is possible to list all members of a class.
The following script demonstrates the included function VariableInfo which will return a string with the type of the passed variable, and in case of an Object, all members with details, including type of Property, callable type (Sub or Function), and parameter names and return type in case of Function. The type name of the object in case of a COM object would be the name of the implemented Interface. Not sure if it works for multiple implemented interfaces, but AFAIK it's not possible to implement multiple interfaces in one class via COM anyway.
It does not support recursion in any way, because this would lead to infinity loops for some types.
This will give you virtually full working reflection in VBS. Great to explore APIs for example with the Microsoft Script Debugger.
' Reflection for VBScript via tlbinfo32.dll
'
' Patrick Strasser-Mikhail 2017-2021
' Ansgar Wiechers 2019
' https://stackoverflow.com/questions/14305750/list-object-methods-and-properties/44459670#44459670
'
' v1.1 2021-02-01: Show values of arrays and objects, but only one level
' Returns a String describing the passed object/variable on the first level,
' no recursion.
Function VariableInfo(obj)
VariableInfo = VariableInfoToLevel(obj, 0, 1)
End Function
' Returns a String describing the passed object/variable on the first level,
' recurse down to level max_level(0=no recursion).
Function VariableInfoToLevel(obj, level, max_level)
Const invokeKindPropertyGet = 0 ' simple data member
Const invokeKindFunction = 1 ' method: Sub or Function
Const invokeKindPropertyPut = 2 ' Docs: has a value setter; reality: more like is settable
Const invokeKindPropertyPutRef = 4 ' Docs: has a reference setter; reality: more like is not settable
If level > max_level Then
VariableInfoToLevel = ""
Exit Function
End If
Dim indent : indent = Space(4 * level)
VariableInfoToLevel = indent
If isEmpty(obj) Or _
isNull(obj) _
Then
VariableInfoToLevel = VariableInfoToLevel & TypeNameFromVarType(VarType(obj))
ElseIf Not IsObject(obj) Then
If Not isArray(obj) Then
VariableInfoToLevel = indent & TypeNameFromVarType(VarType(obj)) & ", Value: [" & obj & "]"
Else
VariableInfoToLevel = indent & TypeNameFromVarType(VarType(obj))
Dim dimension
ReDim sizes(0)
Dim size
On Error Resume Next
Err.Clear
For dimension = 0 To 10 ' deliberate limit to prevent infinite loop
size = Ubound(obj, dimension + 1)
If Err.Number <> 0 Then
' report ther then Index out of Bounds
If Err.Number <> 9 Then
WScript.Echo "Exception " & Err.Number & ": " & Err.Description & "; in " & Err.Source
End If
Exit For
End If
ReDim Preserve sizes(dimension)
sizes(dimension) = size
Next
On Error Goto 0
VariableInfoToLevel = VariableInfoToLevel & "(" & Join(sizes, ",") & ")"
Select Case dimension
Case 1
VariableInfoToLevel = VariableInfoToLevel & " {" & vbCrlf
Dim idx
For idx = LBound(obj) To UBound(obj)
VariableInfoToLevel = VariableInfoToLevel & indent & _
" " & idx & ":" & _
Trim(VariableInfoToLevel(obj(idx), level + 1, max_level)) & vbCrlf
Next
VariableInfoToLevel = VariableInfoToLevel & indent & "}" & vbCrlf
Case 2
VariableInfoToLevel = indent & "{" & vbCrlf
Dim idx1, idx2
For idx1 = LBound(obj, 1) To UBound(obj, 1)
For idx2 = LBound(obj, 2) To UBound(obj, 2)
VariableInfoToLevel = VariableInfoToLevel & indent & _
" " & idx1 & "," & idx2 & ":" & _
Trim(VariableInfoToLevel(obj(idx1, idx2), level + 1, max_level)) & vbCrlf
Next
Next
VariableInfoToLevel = VariableInfoToLevel & indent & " }" & vbCrlf
Case Else
' 0 is empty anyway, more is too complicated to print, just leave it for now
End Select
End If
ElseIf TypeName(obj) = "Nothing" Then
VariableInfoToLevel = indent & "Nothing (The Invalid Object)"
Else
' Object
VariableInfoToLevel = indent & "Object " & TypeName(obj)
'' Need to think about that... True for Err, but not for System.Dictionary
'' Seems Err is very special, and we should compare explicitly with internal/predifined Objects (Err, WScript)
'If varType(obj) <> vbObject Then
' hm, interresting...
' VariableInfoToLevel = VariableInfoToLevel & " with default property (no analysis possible)"
' Exit Function
'End If
Dim TLI
Dim MemberInfo
Dim TypeInfo
Set TLI = CreateObject("TLI.TLIApplication")
VariableInfoToLevel = indent & "Object " & TypeName(obj)
On Error Resume Next
Err.Clear
Set TypeInfo = TLI.InterfaceInfoFromObject(obj)
If Err.Number <> 0 Then
VariableInfoToLevel = VariableInfoToLevel & "; Error " & Err.Number
VariableInfoToLevel = VariableInfoToLevel & ": " & Err.Description
Err.Clear
On Error Goto 0
Exit Function
End If
On Error Goto 0
For Each MemberInfo In TypeInfo.Members
Dim Desc
Dim printNextLevel : printNextLevel = vbFalse
Desc = ""
' based on .Net System.Runtime.IteropService.ComTypes
'' FIXME: Call by Value/Reference and settable seems to be switched some
'' InvokeKind seems to not encode value passing, rather settable/not settable
'' Needs more work to decode byValue/byReference
Select Case MemberInfo.InvokeKind
Case InvokeKindFunction
If MemberInfo.ReturnType.VarType <> 24 Then
Desc = " Function " & TypeNameFromVarType(MemberInfo.ReturnType.VarType)
Else
Desc = " Sub"
End If
Desc = Desc & " " & MemberInfo.Name
Dim ParameterList
ParameterList = Array()
Dim Parameter
For Each Parameter In MemberInfo.Parameters
ReDim Preserve parameterList(UBound(ParameterList) + 1)
ParameterList(Ubound(parameterList)) = Parameter.Name
Next
Desc = Desc & "(" & Join(ParameterList, ", ") & ")"
'Set parameters = Nothing
Case InvokeKindPropertyGet
Desc = " Data Member " & MemberInfo.Name
printNextLevel = vbTrue
Case InvokeKindPropertyPut
' Seems to be
Desc = " Property " & MemberInfo.Name & " [set by val"
If IsGettable(obj, MemberInfo.Name) Then
Desc = Desc & "/get"
printNextLevel = vbTrue
End If
Desc = Desc & "]"
'Stop
Case InvokeKindPropertyPutRef
'Stop
Desc = " Property " & MemberInfo.Name & " [set by ref"
If IsGettable(obj, MemberInfo.Name) Then
Desc = Desc & "/get"
printNextLevel = vbTrue
End If
Desc = Desc & "]"
'Stop
Case Else
Desc = " Unknown member, InvokeKind " & MemberInfo.InvokeKind
End Select
VariableInfoToLevel = VariableInfoToLevel & vbNewLine & _
indent & Desc
If printNextLevel And level < max_level Then
VariableInfoToLevel = VariableInfoToLevel & vbNewLine & _
VariableInfoToLevel(eval("obj." & MemberInfo.Name), level + 1, max_level)
End If
Next
Set TypeInfo = Nothing
Set TLI = Nothing
End If
End Function
Function IsGettable(obj, memberName)
Dim value
On Error Resume Next
Err.Clear
value = eval("obj." & memberName)
Stop
If Err.Number <> 0 And _
Err.Number <> 438 And _
Err.Number <> 450 Then
WScript.Echo Err.Number & ": " & Err.Description
End If
'438: Object doesn't support this property or method
'450: Wrong number of arguments or invalid property assignment
If Err.Number = 438 Or _
Err.Number = 450 Then
IsGettable = vbFalse
Else
IsGettable = vbTrue
End If
End Function
Function IsSimpleType(obj)
If (isEmpty(obj) Or isNull(obj)) And (Not IsObject(obj)) And (Not isArray(obj)) Then
IsSimpleType = vbTrue
Else
IsSimpleType = vbFalse
End If
End Function
' Decode Type Number to something readable
Function TypeNameFromVarType(typeNr)
Dim typeDetails
set typeDetails = CreateObject("Scripting.Dictionary")
typeDetails.add 0, "vbEmpty (uninitialized variable)"
typeDetails.add 1, "vbNull (value unknown)"
typeDetails.add 2, "vbInteger" ' Short?
typeDetails.add 3, "vbLong" ' Integer?
typeDetails.add 4, "vbSingle"
typeDetails.add 5, "vbDouble"
typeDetails.add 6, "vbCurrency"
typeDetails.add 7, "vbDate"
typeDetails.add 8, "vbString"
typeDetails.add 9, "vbObject"
typeDetails.add 10, "Exception"
typeDetails.add 11, "vbBoolean"
typeDetails.add 12, "vbVariant"
typeDetails.add 13, "DataObject"
typeDetails.add 14, "vbDecimal"
typeDetails.add 17, "vbByte"
typeDetails.add 18, "vbChar"
typeDetails.add 19, "ULong"
typeDetails.add 20, "Long" ' realy Long?
typeDetails.add 24, "(void)"
typeDetails.add 36, "UserDefinedType"
If typeDetails.Exists(typeNr) Then
TypeNameFromVarType = typeDetails(typeNr)
ElseIf typeNr > 8192 Then
TypeNameFromVarType = "vbArray{" & TypeNameFromVarType(typeNr - 8192) & "}"
Else
typeNameFromVarType = "Unknown Type " & typeNr
End If
End Function
' Some nice example class to demonstrate all possible interfaces.
Class MyClass
Dim Name_
Dim Name2_
Dim Name3_
Dim Name4_
Dim dict
Private Sub Class_Initialize()
Name_ = "foo"
Name2_ = "bar"
Name3_ = "baz"
Name4_ = "spam"
Set dict = CreateObject("Scripting.Dictionary")
End Sub
Private Sub Class_Terminate()
Set dict = Nothing
End Sub
Public Property Get Name
Name = Name_
End Property
Public Property Let Name(ByVal Value)
Name_ = Value
End Property
Public Property Let Name2(ByRef Value)
Set Name2_ = Value
End Property
Public Property Get Name3
Name3 = Name3_
End Property
Public Property Set Name3(ByVal Value)
Set Name3_ = Value
End Property
Public Property Get Name4
Name4 = Name4_
End Property
Public Property Set Name4(ByRef Value)
Set Name4_ = Value
End Property
Sub TestSub()
WScript.Echo "Test"
End Sub
Sub TestFunc(message)
WScript.Echo "Test: " & message
End Sub
Sub TestFunc2(ByRef message)
WScript.Echo "Test: " & message
End Sub
Function Add(first, second)
Add = first + second
End Function
Function Substract(ByVal first, ByRef second)
Add = first - second
End Function
End Class
Sub testVariableInfo()
Dim variable
' vbEmpty
Wscript.Echo VariableInfo(variable)
variable = Null
Wscript.Echo VariableInfo(variable)
Set variable = Nothing
Wscript.Echo VariableInfo(variable)
Wscript.Echo VariableInfo(Int(23))
Wscript.Echo VariableInfo(cLng(23))
Wscript.Echo VariableInfo(2147483647)
Wscript.Echo VariableInfo(5/4)
Wscript.Echo VariableInfo(4 * Atn(1)) ' Simplest way to pi, not all inverse functions like arcsin are defined.
Wscript.Echo VariableInfo(3.4E38)
Wscript.Echo VariableInfo(CDbl(3.4E38))
Wscript.Echo VariableInfo(cCur(20.123456))
Wscript.Echo VariableInfo(now)
Wscript.Echo VariableInfo("Some Text")
Wscript.Echo VariableInfo(Err)
Dim MyObject
Set MyObject = new MyClass
Wscript.Echo VariableInfo(MyObject)
Set MyObject = Nothing
Dim TestAEmpty()
Wscript.Echo VariableInfo(TestAEmpty)
ReDim TestA1(17)
Wscript.Echo VariableInfo(TestA1)
Dim TestA2(3, 7)
Wscript.Echo VariableInfo(TestA2)
Dim TestA3
TestA3 = Array(4, 5, 6)
Wscript.Echo VariableInfo(TestA3)
Dim dict
Set dict = CreateObject("Scripting.Dictionary")
WScript.Echo VariableInfo(dict)
Set dict = Nothing
End Sub
testVariableInfo
For for more information about the Typelib Interface, get the documentation help file from Microsoft KB artivle 224331
Matthew Curland offers for download at the website to his book Advanced Visual Basic 6 the nice program Type Library Editor (EditTLBEval.exe) as evaluation version, and the according Documentation
Especially in this context I really like the line If you're a Visual Basic developer who refuses to recognize the commonly accepted limitations of VB, this book is definitely for you. by Ted Pattison. Just replace VB by VBScript here.
VBWebProfi gave the hint for TLI, thanks for that. Working out the details and writing the code was several hours of work, though ;-)
VBScript itself does not support type introspection outside the TypeName and VarType functions, which will give you the type of an object, but won't give you access to its internal structure.
As other answers explained there is a DLL that would provide this feature, but it doesn't ship with Windows, and since it was part of an old version of Visual Studio there might not be a legal way to obtain it nowadays.
If you happen to be using HP UFT or QTP then follow these steps:
1) Install any version of MS Visual Studio onto your laptop. (Don't worry about licensing, you won't be running VS)
2) Reboot your computer.
3) Launch UFT or QTP, load a script and hit F11, (or pause at any piece of code that is near the object you want to inspect).
4) Add the object to the Watch window. It can be an Object Repository object or a programmatic description.
If the object exists, the object will now display two Plus (+) signs in the Watch window that can be expanded to show all available Methods and Properties, as well as child objects that can be expanded.
While that is partially true, its incomplete.... Google, GetObjectText_, Methods_, & Propeties_
The referenced methods will only work on objects collected while connected to the cimv2 namespace of a remote host via the WbemScripting.SWbemLocator object. If this object has the ability to work on localhost, it's unapparent to me.
Once you do this you can query any of the classes held therein [Win32_Services,Win32_Drives, etc] and interrogate the objects in the resultset using a For-Next loop on the object like below...
For Each oProp in oObject.Properties_
'be careful here because some propeties may be an object or an array.
'so test for that here using "typename" or "vartype"
wScript.Echo oProp.Name & vbTab & oProp
Next
Or...
For Each oMethod in oObject.Methods_
wScript.Echo oProp.Name
Next
Finally, ...
For Each oProp in oObject.Properties_
'This will display all of an objects properties
oProp.GetObjectText_
Next