AssignSupportToNode only assigns the first node when a list of node IDs is passed

[whocareyw]

Description

The Support.AssignSupportToNode method accepts a list of node IDs (NodeIDs), but only the first node in the list actually receives the support assignment. All subsequent nodes are silently ignored.

Root Cause

The current implementation passes the node list as a raw SAFEARRAY via self._b.in_int_array(NodeIDs):

def AssignSupportToNode(self, NodeIDs, SupportID: int):
    if isinstance(NodeIDs, int):
        NodeIDs = [NodeIDs]
    self._support.AssignSupportToNode(self._b.in_int_array(NodeIDs), SupportID)

While the underlying COM method OSSupportUI::AssignSupportToNode(const VARIANT FAR& varnNodeNo, const VARIANT FAR& varnSupportNo) accepts a VARIANT (which can hold an array), the STAAD.Pro COM server only processes the first element of the array. This is a server-side limitation, not a marshalling issue — confirmed by testing all possible VARIANT wrapping strategies (raw SAFEARRAY, VT_BYREF | VT_ARRAY | VT_I4, VT_ARRAY | VT_I4), all of which produce the same result: only array[0] is assigned.

All official VBA examples in the STAAD.Pro documentation loop over nodes one at a time, and the direct array-passing form is commented out:

'assignSupport = objOpenSTAAD.Support.AssignSupportToNode(SelNodes, pinnedSupport)

Steps to Reproduce

from openstaad import ops

s = ops.connect()
pinned = s.CreateSupportPinned()

# Pass a list of 4 nodes
s.AssignSupportToNode([5, 6, 7, 8], pinned)

print(s.GetSupportNodes())
# Expected: [..., 5, 6, 7, 8]
# Actual:   [..., 5]  ← only the first node

Environment

• STAAD.Pro 2024
• Python 3.12 / comtypes
• Windows 11

Suggested Fix

Loop over the node list and call the COM method once per node, matching the pattern used in all official VBA examples:

def AssignSupportToNode(self, NodeIDs, SupportID: int):
    if isinstance(NodeIDs, int):
        NodeIDs = [NodeIDs]
    for node_id in NodeIDs:
        self._support.AssignSupportToNode(node_id, SupportID)

This has been tested and confirmed working — all nodes in the list receive the support assignment correctly.