My Portal Project

As you can see in the errorCatch line, I named this agent “doSendMessage” so you will need to customize this for your purposes. For the purposes of brevity I will not go into detail for each line, but rely on my REM comments to explain what each section is.

Sub Initialize
    On Error Goto errorCatch
    Dim s As New NotesSession
    Dim domParser As NotesDOMParser
    Dim nodeDoc As NotesDOMDocumentNode,nodeNode As NotesDOMElementNode
    Dim nodeResults As NotesDomElementNode
    Dim dbThis As NotesDatabase
    Dim docCtx As NotesDocument
    Dim streamOut As NotesStream
    Dim strInput As String, strIpAddress As String
    ' set defaults
    Set dbThis = s.CurrentDatabase
    Set docCtx = s.DocumentContext
    Set domParser = s.CreateDOMParser
    Set nodeDoc = domParser.Document
    Set streamOut = s.CreateStream
    bSuccess = False
    strIpAddress = docCtx.Remote_Addr(0)
    If Not setArrayDefaults Then          ' initialize arrays default values
        Goto createDomResults          ' strOut is set within setArrayDefaults
    End If
    strInput = docCtx.Request_Content(0)     ' grab POST data
    If Not isAuthenticated(s, strInput) Then  ' does the request have a valid user/pass?
        Goto createDomResults          ' strOut is set within isAuthenticated
    End If
    If Not getParams(s, strInput) Then      ' grab parameters from POST data
        Goto createDomResults          ' strOut is set within getParams and/or sub-function
    End If
    If Not doMail(s, dbThis, strIpAddress) Then ' send the mail
        Goto createDomResults        ' strOut is set within doMail function
    End If
    bSuccess = True    
createDomResults:
    Set nodeNode = setDefaultDom(nodeDoc)      ' create a response wrapper
    Call domParser.setOutput(streamOut)     ' to get xml doc we need to output to a notesStream
    Call domParser.Serialize         ' xml doc contents into stream
    Print {content-type:text/xml; charset=utf-8} 'REQUIRED
    Print {< ?xml version="1.0" encoding="UTF-8"?>} + streamOut.ReadText
    Exit Sub
errorCatch:
    strOut = “Error in doSendMessage:init in line: ” & Erl() & ” error$: ” & Error$
    bSuccess = False
    Exit Sub
End Sub

So we setup some of our arrays, grab the request_content text (the xml), check for authentication, grab the parameters from the xml and send the message. If everything is successful, we can then send a response back to the requesting client and everyone is happy! So let’s look into some of these functions. First is the setArrayDefaults function which does what it is named for.

Function setArrayDefaults() As Boolean
    ' function to initialize arrays with default values
    setArrayDefaults = False
    On Error Goto errorCatch
    arrParams(0) = "sendto"
    arrParams(1) = "copyto"
    arrParams(2) = "blindcopyto"
    arrParams(3) = "subject"
    arrParams(4) = "message_body"
    arrparams(5) = "from"
    arrParams(6) = "attachments"
    setArrayDefaults = True
    Exit Function
errorCatch:
    strOut = "Error in doSendMessage:setArrayDefaults in line: " & Erl() & " error$: " & Error$
    bSuccess = False
    Exit Function
End Function

The arrParams array is the node names of the parameters we want from the XML stream. So if this goes off without a hitch, we move onto the isAuthenticated function which checks the username and password combination that comes in with the request. For the sake of our example, our authentication method is to take a username and pass it through the LotusScript “HashPassword” method of the NotesSession class. So the password is the username hashed. Our function will extract the proper nodes from thhe XML stream and compare the hashed username to the password included.

Function isAuthenticated(s As NotesSession, strInput As String) As Boolean
    ' function to determine validity of user/pass combo
    On Error Goto errorCatch
    Dim domParser As NotesDOMParser
    Dim nodeDoc As NotesDOMDocumentNode
    Dim nodeList As NotesDOMNodeList
    Dim nodeNode As NotesDOMElementNode
    Dim authName As String, authPass As String
    Set domParser = s.CreateDOMParser
    Call domParser.parse(strInput)
    Set nodeDoc = domParser.Document
    isAuthenticated = False
    strOut = "not a valid username / password pair"
    Set nodeList = nodeDoc.GetElementsByTagName("auth_name") ' grab list of user name nodes
    If nodeList.NumberOfEntries > 0 Then              ' if we have one
        Set nodeNode = nodeList.GetItem(1)          ' grab the actual node
        If nodeNode.HasChildNodes Then              ' check to see if it has values
            authName = nodeNode.FirstChild.NodeValue ' grab value
        Else
            Exit Function                   ' we have a node with no values
        End If
    Else
        Exit Function ' we do not have a username node
    End If
    ' rinse and repeat with auth_pass
    Set nodeList = nodeDoc.GetElementsByTagName("auth_pass")
    If nodeList.NumberOfEntries > 0 Then
        Set nodeNode = nodeList.GetItem(1)
        If nodeNode.HasChildNodes Then
            authPass = nodeNode.FirstChild.NodeValue
        Else
            Exit Function
        End If
    Else
        Messagebox "no auth pass"
        Exit Function
    End If
    ' to get a username and password combo, session.hashpassword method
    If s.VerifyPassword(authName, authPass) Then          ' verify username and password
        isAuthenticated = True
        strOut = ""
    End If
    Exit Function
errorCatch:
    strOut = "Error in doMessageSend:isAuthenticated in line: " & Erl() & " error$: " & Error$
    isAuthenticated = False
    Exit Function
End Function

So there you have it, our first extraction of a value(s) from our XML stream. I do to want to go into too much detail on using an XML parser, hopefully my REM comments will help fill in any of the gaps. In my example, I am using the DOM parser which puts the entire XML tree into memory before extracting values, but you could also use the SAX parser.

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This entry was posted on Saturday, November 5th, 2005 at 9:41 am and is filed under Notes/Domino, Code Bin, Web Development. You can follow any responses to this entry through the RSS 2.0 feed. Both comments and pings are currently closed.