Lotus Notes FAQ Visit Our Sponsor!

How do you sort a document collection?

Here is an example that does a bubble sort on the document collection using two fields as the sort key:
Sub Swap(doc1 As NotesDocument ,doc2 As NotesDocument)
 Dim d As NotesDocument
 Set d = doc1
 Set doc1 = doc2
 Set doc2 = d     
End Sub

Sub CollectionToSortedArray(col As NotesDocumentCollection, docs() As NotesDocument)     
 Dim i As Integer
 Dim doc As NotesDocument
 Dim n As Integer, sorted As Integer
 Dim s1, s2 As String
 n = col.count
 Redim docs(n) As NotesDocument
 ' push to array
 For i = 0 To n - 1
   Set docs(i) = col.GetNthDocument(i+1)
 'bubble sort array
 sorted = False
 Do While (sorted = False)          
   sorted = True
   For i = 0 To n - 2
     ' sort based on QuoteNo and ItemNo fields
     s1 = docs(i).QuoteNo(0) & docs(i).ItemNo(0)
     s2 = docs(i+1).QuoteNo(0) & docs(i+1).ItemNo(0)
     If(Strcomp(s1, s2, 5) = 1) Then  'No Pitch, No Case Compare
       Call Swap(docs(i),docs(i+1))
       sorted = False
     End If
End Sub

Here's another sample using a Merge Sort which is faster for large collections:

Sub qsort(element, sortkeys)
  ' To be called by REFERENCE
  Call mergesort(element, sortkeys, Lbound(sortkeys), Ubound(sortkeys), False)
End Sub

Sub mergesort(element, sortkeys, l As Integer, r As Integer, isclass As Variant)
  ' From Paul Hudson (paulh@harlequin.co.uk)
  ' Called by qsort, but can be used on its own
  Dim i As Integer, j As Integer, k As Integer, m As Integer
  Dim b1(), b2()

  If (r - l > 0) Then
    m = (r + l) \ 2
    Call mergesort(element, sortkeys, l, m, isclass)
    Call mergesort(element, sortkeys, m + 1, r, isclass)
    Redim b1(l To r)
    Redim b2(l To r)
    For i = l To m
      If isclass Then
        Set b1(i) = element(i)
        b1(i) = element(i)
      End If
      b2(i) = sortkeys(i)
    For j = m+1 To r
      If isclass Then
        Set b1(r + m + 1 - j) = element(j)
        b1(r + m + 1 - j) = element(j)
      End If
        b2(r + m + 1 - j) = sortkeys(j)
    i = l
    j = r
    For k = l To r
      If b2(i) < b2(j) Then
        If isclass Then
          Set element(k) = b1(i)
          element(k) = b1(i)
        End If
        sortkeys(k) = b2(i)
        i = i + 1
        If isclass Then
          Set element(k) = b1(j)
          element(k) = b1(j)
        End If
        sortkeys(k) = b2(j)
        j = j - 1
      End If
  End If
End Sub

Applies to Notes Versions: 4 4.5 4.6 5
Last Modified: February 28, 1999