How to sort a NotesDocumentCollection in Lotusscript

Max — Tue, 30 May 2006 21:28:00 +0000

This Lotusscript function sorts a document collection on one or multiple fields.

I have previously used several other algorithms that use a view to sort the collection, these however have the drawback that they become very inefficient (i.e. slow) as the number of documents in the view used for sorting grows. The solution presented below does not have this problem.

It has been developed and tested in Lotus Notes 6.5.3 but should work in all ND6 (release 6) and possibly earlier Lotus Notes releases too (if you test this successfully or unsuccessfully write a comment to this post and everyone will know).

Example of use:

Dim fieldnames(0 To 2) As String fieldnames(0) = "SKU" fieldnames(1) = "OrderDate" fieldnames(2) = "Client" Set collection = SortCollection (collection, fieldnames)

Function to sort DocumentCollection:

Function SortCollection(coll As NotesDocumentCollection, fieldnames() As String) As NotesDocumentCollection

' ------------------------------------------------ ' --- You may use and/or change this code freely ' --- provided you keep this message ' --- ' --- Description: ' --- Sorts and returns a NotesDocumentCollection ' --- Fieldnames parameter is an array of strings ' --- with the field names to be sorted on ' --- ' --- By Max Flodén 2005 - http://www.tjitjing.com/ ' ------------------------------------------------


Dim session As New NotesSession

Dim db As NotesDatabase

Dim collSorted As NotesDocumentCollection

Dim doc As NotesDocument

Dim i As Integer, n As Integer

Dim arrFieldValueLength() As Long

Dim arrSort, strSort As String

Dim viewname As String, fakesearchstring As String
viewname = "$All" 'This could be any existing view in database with first column sorted

fakesearchstring = "zzzzzzz" 'This search string must NOT match anything in view

Set db = session.CurrentDatabase
' ---

' --- 1) Build array to be sorted

' ---
'Fill array with fieldvalues and docid and get max field length

Redim arrSort(0 To coll.Count -1, 0 To Ubound(fieldnames) + 1)

Redim arrFieldValueLength(0 To Ubound(fieldnames) + 1)

For i = 0 To coll.Count - 1

Set doc = coll.GetNthDocument(i + 1)

For n = 0 To Ubound(fieldnames) + 1
If n = Ubound(fieldnames) + 1 Then

arrSort(i,n) = doc.UniversalID

arrFieldValueLength(n) = 32

Else

arrSort(i,n) = "" & doc.GetItemValue(fieldnames(n))(0)

' Check length of field value

If Len(arrSort(i,n)) > arrFieldValueLength(n) Then

arrFieldValueLength(n) = Len(arrSort(i,n))

End If

End If
Next n

Next i
'Merge fields into list that can be used for sorting using @Sort function

For i = 0 To coll.Count - 1

If Not strSort = "" Then strSort = strSort & ":"

strSort = strSort & """"

For n = Lbound(fieldnames) To Ubound(fieldnames) + 1

strSort = strSort & Left(arrSort(i,n) & Space(arrFieldValueLength(n)), arrFieldValueLength(n))

Next n

strSort = strSort & """"

Next i
' ---

' --- 2) Sort array

' ---

arrSort = Evaluate("@Sort(" & strSort & ")")
' ---

' --- 3) Use sorted array to sort collection

' ---

Set collSorted = coll.Parent.GetView(viewname).GetAllDocumentsByKey(fakesearchstring)
For i = 0 To Ubound(arrSort)

Set doc = db.GetDocumentByUNID(Right(arrSort(i), 32))

Call collSorted.AddDocument(doc)

Next i
' ---

' --- 4) Return collection

' ---

Set SortCollection = collSorted

End Function

(This article is previously published and has been moved to this blog)

[Update: Instead of using Evaluate and @Sort in section 2 in the code you can of course use any of your favourite sort routines. Or search the Net for one, there are many out there.]

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How to sort a NotesDocumentCollection in Lotusscript