Dim stack As New Stack()
Call stack.push("Domino")
Call stack.push("Notes")
Call stack.push("R7")

Print "First: " & stack.pop()
Print "Second: " & stack.pop()
Print "Third: " & stack.pop()
' This will produce the output:
' R7
' Notes
' Domino


Thanks to Vitezsla Vit VLCEK and Chad ”Smiley” Schelfhout for pointing out bugs in the original class.

• Stack.ls

1. Microsoft XML Parser: 0.2 seconds
2. NotesSAXParser: 2.2 seconds
3. NotesDOMParser: 2.5 seconds

When executed on a Domino server, the result was a bit different, since the server is a bit old:

1. Microsoft XML Parser: 1.0 seconds
2. NotesSAXParser: 5.0 seconds
3. NotesDOMParser: 7.7 seconds

This is a new version that handles siblings better, and not getting out of stack space


Public Sub serializeNode(node As NotesDOMNode_
, outStream As NotesStream)
On Error Goto catch

If node.NodeType = DOMNODETYPE_ELEMENT_NODE _
And Not endWritten Then
Call outStream.writeText("")
End If
Exit Sub
catch:
Error Err, Err & Lsi_Info(2) & ":" & Erl & "|" & Error
End Sub


• pass both the NotesDOMDocumentNode AND the original NotesDOMParser at all times
• write my own Serialize method
• pass the XML string only, and do the parsing at each method. I think this would be really slow…

To further illustrate what I want, here is an example:

Public Sub testDOMParser()
Dim parser As NotesDOMParser
Dim inStream As NotesStream
Dim node As NotesDOMDocumentNode
Set inStream = session.createStream()
Call inStream.open("c:temptest.xml")
Set parser = session.createDOMParser(inStream)
Call parser.process()
Set node = parser.document
Call serializeDocument(node)
End Sub
Public Sub serializeDocument(node As NotesDOMDocumentNode)
' Here, I want to do something like this:
Dim outStream As NotesStream
Dim parser As NotesDOMParser
Set outStream = session.createStream()
Set parser = session.createDOMParser(node, outStream)
parser.exitOnFirstFatalError = True
Call parser.serialize()
Print "Serialized tree: " + outStream.readText()
End Sub


Anyone who have had any experience with this and are willing to share their thoughts? We are talking R6 here…

The HTML code must refer to the images via URL:s containing cid and the ”path” to the image, like this:

<img src="cid:imagename.gif" />


Found this great tip via LDD, posted by Raymond Neeves.


Dim v As New Vector()
Call v.addElement("Domino")
Call v.addElement("Notes")
Call v.addElement("R5")
Print "Elements are: " & v.toString()


Results in the text ”Elements are: Domino, Notes, R5”

You may download and use the code at your own risk.

On request, I have changed the license from GPL to LGPL on these files.

I have updated the Vector class with a bug fix that Mikkel Heisterberg kindly supplied. The code is now also GPL:ed.

The definition of a class looks like this:

Public Class Car
End Class


The Public tells that this class will be seen outside the agent or scriptlibrary, where the class is created. You can also make a Private class, that only the agent or script library can see, where the class is defined:

Private Class Car
End Class


To create an instance of a class, you use the New keyword:


Dim myCar as New Car()


or:


Dim myCar as Car
Set myCar = New Car()


To add functionality to a class, you can create functions, subroutines, property getters and property getters. I will not explain the last ones, as they easily can be transformed into functions and subs. To add a function, that returns a value, you write like:


Public Class Car

End Class


To add a subroutine, that does not return a value, you write:


Public Class Car

End Class


There are two special subroutines, delete and new:


Public Class Car

End Class


The new subroutine, also called constructor, is called whenever you use the New keyword to create a new instance of the class. The delete subroutine is called when there are no references to the object.

To add arguments that can be passed to subroutines and functions, just add them like you do to any ordinary function or subroutine:


Public Class Car

End Class


To add instance member variables, declare them inside the class, without the usual Dim:


Public Class Car

End Class


To use instance member variables, you handle them like any other variable. A special case is show below, when a function has an argument variable, that has the same name as the instance variable. The keyword Me is used to denote the current object, and when saying Me.topSpeed, we mean the instance member variable topSpeed, and not the function argument variable :


Public Class Car

End Class


To remove an object from memory, you use the Delete keyword. This removes the actual object from memory, and all references that are using the object can not use it any more.


Dim myCar as New Car(120)
Delete myCar


If you just want to relase a reference to an object, you use the Nothing keyword. This will only remove the specified reference, but the object is still in memory, until ALL references are removed.


Dim myCar as New Car(120)
Set myCar = Nothing


You can test if an object reference is still valid, by comparing the object reference to Nothing:


Dim myCar as New Car(120)
' Do some work...
If myCar Is Nothing _
Then Error 2000, "Object reference not valid"


To check what type an object reference is, you can use the IsA keyword. This is useful, when you don´t know at compile time what type of object you handle:


Dim myVehicle as Variant

If userName = "Donald" Then
Set myVehicle = New Helicopter()
Else
Set myVehicle = New Bicycle()
End If
If myVehicle IsA "Helicopter" _
Then Print "Fly away!"


The problem with the above is, that if you want to assign non-objects to the same variable, you must test if the variable is an object, before trying to use IsA or testing if it is Nothing:


Dim myVehicle as Variant

If IsObject(myVehicle) Then
If myVehicle IsA "Helicopter" _
Then Print "Fly away!"
Else
Print "No object, probably strange user..."
End If


To get the name of the class that was used to create an object instance, use the keyword Typename:


Dim myCar As New Car(120)
' Will print "Car":
Print "The type of object is: " & Typename(myCar)...


Ok, let´s do some useful with our new knowledge, let´s create a working Car class. The start sub must be called before the accelerate() method is called.


Public Class Car

Public Function getCurrentSpeed() As Integer
getCurrentSpeed = currentSpeed
End Function
End Class


To use our class, we can write:


Dim car As New Car(120)
Call car.start()
Do While car.getCurrentSpeed() < car.getTopSpeed() Print "Current speed is: " & car.accelerate() Loop Print "Top speed " & car.getTopSpeed() & " reached!" Call car.stop() Print "Car parked!" Set car = Nothing

There is more to learn about classes in LotusScript, so stay tuned for the next article! Meanwhile, check the following links:

"Using the object-oriented features of LotusScript" on Lotus Developer Domain, great explanation of all (?) advantages!
"User-defined classes" in the Domino Designer Help 5.0.3
The Unfinished LotusScript Book by Julian Robichaux
Bill Buchan's Lotus Notes programming tips