In LotusScript, when using NotesItem AppendToTextList method to build a UNID list, the maximum number of UNIDs a NotesItem can hold is 964, which is about 30848 bits (32-bit UNID * 964). The 965th UNID that is appended will give an error of cannot append text to a null item. An actual field on a NotesDocument probably can only contain 16K, so the number of UNIDs can be put in a field is much smaller.
If you have to put more UNIDs in a field on a document, multiple fields would have to be used. A sample code of dynamically writing into multiple fields and dynamically reading from possible multiple fields shown below.
'Dynamically write to multiple fields Dim numUnids As Integer Dim unidArray As Variant Dim arrayItem As NotesItem Dim fieldNum As Integer Dim fieldName As String Dim i As Integer Dim doc As NotesDocument 'set the limit of the number of UNIDs a field can contain to 400 fieldUnidsLimit = 400 fieldNum = 1 numUnids = 0 'references is a list of UNIDs we got in memory by early processing Forall x In references 'count the total number of UNIDs numUnids = numUnids + 1 End Forall If numUnids <= fieldUnidsLimit Then 'the number of UNIDs need to store on the document is less than the limit 'use a single field-DocRefs field to hold the UNIDs doc.DocRefs = references Else 'the number of UNIDs need to store on the document is greater than
the limit, need to dynamically create more fields to hold the UNIDs, the field name would be used are DocRefs1, DocRefs2 ... 'Redim sets first element as index 0, so need to redim to the limit minus 1 Redim unidArray(fieldUnidsLimit-1) As String For i = 1 To numUnids 'fieldUnidsLimit*(fieldNum-1) calculates the number of Unids that have been put on the doc unidArray(i-1-fieldUnidsLimit *(fieldNum-1)) = references(i-1) If i = fieldUnidsLimit * fieldNum Or i = numUnids Then 'a field is full or we reach the end, put the array on the doc,
erase the array, and prepare for the next field fieldName = "DocRefs" & Cstr(fieldNum) Set arrayItem = doc.ReplaceItemValue(fieldName, unidArray) Call doc.Save(True, True) If i < numUnids Then 'more fields needed, increment fieldNum for next field fieldNum = fieldNum + 1 'empty the array and reDim for the next field Erase unidArray If (numUnids - i) <= fieldUnidsLimit Then Redim unidArray(numUnids - i - 1) Else Redim unidArray(fieldUnidsLimit - 1) End If End If End If Next End If '*************************** 'Dynamically read from possible multiple fields Dim fieldName As String Dim fieldNum As Integer Dim arrayItem As NotesItem If doc.DocRefs(0) <> "" Then 'this is the case there is only one field 'do operations here...... Else 'If the DocRefs is not on the doc, we know there are mutiple fields of that fieldNum = 1 fieldName = "DocRefs" & Cstr(fieldNum) While doc.HasItem(fieldName) Set arrayItem = doc.GetFirstItem(fieldName) 'do operations here...... fieldNum = fieldNum + 1 fieldName = "DocRefs" & Cstr(fieldNum) Wend End If