Component Example 2: Resolving an email address

This example shows how an email address string entered or changed by the user is automatically turned into an existing email address when possible.

The example uses the Travel Agency case (Expanded Version).

In the data model, to the PERSON table, add an EMAIL column based on a regular CHAR(60) domain (On Oracle7: VARCHAR2).

Add a constraint:

Set the SQL statement to:

UPDATE person
SET    email =
(
    INVOKE usmail.resolve_address WITH
    SELECT email
)
WHERE email IS NOT NULL

Code of invoked subprogram

The component establishes a connection to a Microsoft Exchange server using Microsoft's standard MAPI component. The exchange server returns the email address if it can be found. If not, the original input string is returned.

Visual Basic code of subprogram directly invoked by USoft:

Public Function resolveAddress(address As String, _
                                    Optional profile_name As String, _
                                    Optional password As String) _
                                    As String

   Dim original_address As String
   Dim objMessage As Object
   Dim objSession As Object
    On Error GoTo on_error
    original_address = address
    resolveAddress = address
    Set objSession = newSession(profile_name:=profile_name, _
                                 password:=password, _
                                 no_mail:=True)
    ' Create a new message
   Set objMessage = newMessage(objSession, address)
    ' Check how the address will be resolved
   resolveAddress = resolveMsgAddress(objMessage)
    If (resolveAddress = USOFT_UNRESOLVED_ADDRESS) Then
      resolveAddress = original_address
   End If
    cleanUp objSession, objMessage
    Exit Function
 on_error:
   If Not ignoreError() Then
      resolve_address = original_address
      showError "resolveAddress"
   End If
    cleanUp objSession, objMessage
End Function