Object Oriented Lotusscript for beginners – Part 2

In my previous post I wrote about whyI use object oriented Lotusscript. Let’s look at how it can be used in a real-life application.
At my work I developed a system to handle insurance claims. Each claim can have one or more claimants, people or parties that have either BI (bodily injury) or PD (property damage) claims related to an accident. Each claimant get a reserve setup, an amount of money the adjuster think it will cost to settle the claimant. There are two reserves for each claimant, one for loss payments and one for expense payments. The latter can be payments for police reports, field adjusters, lawyer fees, etc while loss payments are the actual damages (payments to body shops, medical payments, etc).
When payments are made, the reserve amounts are reduced, until reaching zero. No more payments can be done then until the reserve is increased. Each adjuster have a limit to how large reserve he or she can set, higher reserve must be approved by a manager.
Data storage
When the claim system was first put in place, all reserves and payments werestored in the Notes database. They were then (manually) transferred into a backend system built in Visual FoxPro. But after a few years, a COM object (dsClaimLink) was developed and the Notes database is now sending all financial transaction into the backend, and retrieving financial information the same way when needed. Claim information is stored in the Notes database, as is claimant information. Some claimant information. a sub-set of the data stored in Notes,is sent to the backend as well.
Original design
Initially I built a large number of functions and subroutines, organized in different script libraries based on functionality.This actually worked really good, and the code was fairly easy to maintain, modify and expand. When the financial transactions were moved to the backend, I just had to modify the function GetAvailableAmount() to call the backend instead of looking up the amount in the Notes database. But it was still not very flexible, andI had some code that was duplicated in many places (most of it related to calling the COM object). So about two years ago, I started refactoring my code, both to make it faster and easier to maintain, by using object oriented Lotuscript.
Beloware examples of the code in the script library Class.ClaimData class. This is not my exact production code, I have removed a number of lines to make the example more clear.
The ClaimData class (described in next posting)contains an array of claimants, each of those an object. Each claimant object in turn contains an object containing the different amounts (loss reserve/loss payments, expense reserve/expense payments, recovery amount, etc).
First, let’s look at the AmountData object.
Class AmountData
    Public lr As Currency        ' Loss Reserve
    Public er As Currency        ' Expense Reserve
    Public lp As Currency        ' Loss Payments
    Public ep As Currency        ' Expense Payments
    Public slp As Currency        ' Supplemental Loss Payments
    Public sep As Currency        ' Supplemental Expense Payments
    Public rec As Currency        ' Recovery amount
    Public lossavail As Currency
    Public expavail As Currency

    Public Sub New()
        rec = 0
        slp = 0
        sep = 0
        lr = 0
        er = 0
        lp = 0
        ep = 0
        lossavail = -1
        expavail = -1
    End Sub
    Public Sub Load(claimnumber As String, claimant As Integer)
        Dim success As Integer
        Dim servaddress As String
        Dim xmldata As String
        Dim claimlink As ClaimLink    ' Object to connect to backend
        Set ClaimLink =  New ClaimLink()   ' Create object/class
        If claimant = 0 Then          ' Get total amounts for all claimants    
            success = claimlink.GetClaimStatus(claimnumber, Today())
        Else                          ' Get amounts for selected claimant
            success = claimlink.GetAmountsByClaimant(claimnumber, claimant, Today())
        End If
        If success = True Then        ' Data returned successfully
            xmldata = claimlink.GetDataXML()
            rec = Cstr(Ccur(XMLGetValue(xmldata,"recovery")))    
            slp = Cstr(0-Ccur(XMLGetValue(xmldata,"losssup")))
            sep = Cstr(0-Ccur(XMLGetValue(xmldata,"expsup")))        
            If claimant = 0 Then     ' All claimants
                lr = Cstr(Ccur(XMLGetValue(xmldata,"lossorig")) + Ccur(XMLGetValue(xmldata,"losschg")))
                er = Cstr(Ccur(XMLGetValue(xmldata,"exporig")) + Ccur(XMLGetValue(xmldata,"expchg")))
            Else                     ' Specified claimant
                lr = Cstr(Ccur(XMLGetValue(xmldata,"lossres")) - Ccur(slp) + Ccur(rec))
                er = Cstr(Ccur(XMLGetValue(xmldata,"expres")) - Ccur(sep))
            End If
            lp = Cstr(0-Ccur(XMLGetValue(xmldata,"losspaid")) - Ccur(slp))
            ep = Cstr(0-Ccur(XMLGetValue(xmldata,"exppaid")) - Ccur(sep))
            lossavail = Ccur(lr) - Ccur(lp)
            expavail = Ccur(er) - Ccur(ep)
        End If    
    End Sub
End Class
As you perhaps noticed, I encapsulated the dsClaimLink functionality in an obect as well. I am also using my own XML parsing functions, as the system was built in Notes R5.
When the object is created, I do not lead the amounts directly. I just set all amounts to 0, with two exceptions. The available amounts are set to -1 (a value they will normally never have). This indicate that data have not been loaded, or that the attempt to load data failed.
The Load() method of the class call the COM object (dsClaimLink) withone of two functions depending on how the method is called. This let meuse the AmountData object notjust for amounts for a specified claimant, but also for claim level amounts,totals for all claimants.
Next we have a small object used to decide if a claimant is open or closed.The expense and loss parts of a claimant can be closed and (re-)openedindividually. If either is open, the claimant is open, if both are closed, the claimant is considered closed. That is why I built this object, to get an easy status indication in the claimant object.
Class ClaimantStatusData
    Public loss As String
    Public expense As String
    Public claimant As String
    Public Sub new(doc As NotesDocument)
        If Lcase(doc.LossClosed(0)) = "yes" Then
            Me.loss = "closed"
            Me.loss = "open"
        End If
        If Lcase(doc.ExpensesClosed(0)) = "yes" Then
            Me.expense = "closed"
            Me.expense = "open"
        End If
        If Me.expense = "closed" Then
            If Me.loss = "closed" Then
                Me.claimant = "closed"
                Me.claimant = "open"
            End If
            Me.claimant = "open"
        End If
    End Sub
End Class
Nothing very complicated, but a big help later on.
The final class I will show today is the actual ClaimantData class. As you can see,I am using the classed I described earlier here. I have removed some code in order to make it easier to follow. Just one more note, I use a field/value called ParentUNID to keep track of all documents that belong to a claim. The claim number is not associated with the claim at first, so I needed some other unique identifier. I choose to use the UniversalID of the main document (“Loss Notice”) at the time it is received into the database. Even if the actual UniversalID would change, e.g. through a replication conflict, that field will never change again.
The class is farly simple. The ClaimantData object will load amount and claimant status wheninitialized. They are then available, together with the methods of the class, to the calling code.
Class ClaimantData
    Public claimantdoc As NotesDocument
    Public unid As String    ' Store UniversalID of claimant document
    Public parentunid As String        
    Public amounts As AmountData
    Public claimcare As ClaimCareData
    Public status As ClaimantStatusData
    Public Parallel As Integer
    Public Sub New(doc As NotesDocument)
        Dim claimnumber As String
        Dim claimant As Integer
        Set claimantdoc = doc
        unid = doc.UniversalID
        parentunid = doc.GetItemValue("ParentUNID")(0)
        claimnumber = doc.GetItemValue("ClaimNumber")(0)
        claimant = Cint(doc.GetItemValue("Claimant_Number")(0))
        If Lcase(doc.GetItemValue("TransferredToParallel")(0)) = "yes" Then
            Parallel = True
            Parallel = False
        End If
        Set amounts = New Amounts(claimnumber, claimant)
        Set status = New ClaimantStatusData(doc)
    End Sub
    Public Function GetValue(fieldname) As Variant
        GetValue = claimantdoc.GetItemValue(fieldname)(0)
    End Function
    Public Function SetValue(fieldname, Byval value As Variant) As Variant
        Call claimantdoc.ReplaceItemValue(fieldname, value)
    End Function
    Public Function GetVariant(fieldname) As Variant
        GetVariant = claimantdoc.GetItemValue(fieldname)
    End Function
    Public Sub Save()
        Call claimantdoc.Save(True,True)
    End Sub
    Public Function DisplayName() As String
        If Fulltrim(GetValue("Claimant_Name")) = "" Then
            DisplayName = GetValue("Claimant_Company")
            DisplayName = GetValue("Claimant_Name")
        End If
    End Function
    Public Function GetXML()        
        Dim tempxml As String
        If claimantdoc Is Nothing Then
            Msgbox "Claimant document is not loaded, no data returned.",,"ClaimantData.GetXML()"
            GetXML = ""
            Exit Function
        End If    
        tempxml = "<claimntno>" & claimantdoc.GetValue("Claimant_Number") & "</claimntno>" & CRLF    
        tempxml = tempxml + "<extclmntno>" & claimantdoc.getValue("ClaimantNumberExternal") & "</extclmntno>" & CRLF    
        tempxml = tempxml + "<classcode>" & claimantdoc.pClassCode(0) & "</classcode>" & CRLF    
        tempxml = tempxml + "<cvgcode>" & claimantdoc.Claimant_LossType(0) & "</cvgcode>" & CRLF    
        tempxml = tempxml + "<table>" & claimantdoc.pTable(0) & "</table>" & CRLF    
        If claimantdoc.Unknown(0)="Yes" Then
            tempxml = tempxml + "<claimntnam>* unknown *</claimntnam>" & CRLF
        Elseif claimantdoc.Claimant_Name(0)="" Then
            tempxml = tempxml + "<claimntnam>" & dsClaimLink.EncodeXML(claimantdoc.Claimant_Company(0)) & "</claimntnam>" & CRLF
            tempxml = tempxml + "<claimntnam>" & dsClaimLink.EncodeXML(claimantdoc.Claimant_Name(0)) & "</claimntnam>" & CRLF
        End If    
        ' Check if we have amounts loaded
        If Not amounts Is Nothing Then
            tempxml = tempxml + "<lossamt>" & Format$(amounts.lp,"###0.00") & "</lossamt>" & CRLF    
            tempxml = tempxml + "<expamt>" &  Format$(amounts.ep,"###0.00") & "</expamt>" & CRLF    
        End If
        GetXML = tempxml
    End Function
End Class
There is a function to get an XML representation of the claimant. This one is used when data is sent to the dsClaimLink COM object. I also have a function to return the name to display, either the person name or the company name of the former is blank. I could have implemented this using the Get/Set statements, but they have to be defined as a pair and this is a read-only property of the object.

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