Issue: #1670 Status: IMPLEMENTED & VERIFIED (2026-09-27) — branch task/issue-1670, commit 230b9e6fe Screen: Assign Test Plan Roles — gui/templates/usermanagement/usersAssignPlan.html BFF: unchanged (the sort is 100 % client-side; GET /roles/meta/tplan-roles already ships every role name) i18n: unchanged (no new label — the sort key reads the already-localized <option> text)

Legacy gui/templates/dashio/usermanagement/usersAssign.tpl:111-120 pushes exactly one column setting into the legacy DataTable:

addToDataTablesConfig = {
  "columnDefs": [ { "searchable": false, "targets": 1 }],
  "language": { "search": "{$labels.User}" }
};

There is no orderable key anywhere in usersAssign.tpl, and DataTables.inc.tpl:100-104 only adds {lengthMenu, stateSave:true}. The legacy 2-column grid (usersAssign.tpl:216-219 — th = User + Test Plan Role, the cell being a <select> at :239-271) therefore had both columns orderable: clicking Test Plan Role grouped the user list by the assigned role.

The modern plan screen had disabled ordering on that column:

{ searchable: false, orderable: false, targets: 4 }   // gui/templates/usermanagement/usersAssignPlan.html:503 (pre-fix)

so Plan Role Override was neither sortable nor searchable — while its twin usersAssignProject.html:505-508 (same legacy template, same config) deliberately keeps the role column sortable. The two modernized twins diverged from each other and from 1.9.20.

gui/templates/usermanagement/usersAssignPlan.html only, +43/-3:

1. Orderability restored — columnDefs targets:4 is now { searchable: false, orderDataType: 'tlu-role-select', targets: 4 }. The column stays non-searchable exactly as legacy had it; the # ordinal (0) stays non-orderable.

2. A real sort key — re-enabling orderable alone is not enough, and this is the non-obvious part of the gap. The cell contains a <select>, so DataTables' default string key is every option label concatenated:

   srt1670guest     -> "<inherited> guest<reserved system role 1>…<no rights>test designerguest…leader"
   srt1670designer  -> "revert to inherited test designer<reserved system role 1>…leader"
   

   All rows share one long suffix and differ only in the first label, so a naive sort is effectively a coin toss between <inherited> … and revert to inherited … — not the "group the list by assigned role" behaviour legacy intent describes. The fix registers a sort key provider that returns the selected option's label:

   $.fn.dataTable.ext.order['tlu-role-select'] = function (settings, col, visCol) {
     var nodes = this.api().column(visCol, { order: 'index' }).nodes();
     var out = [];
     for (var i = 0; i < nodes.length; i++) {
       var sel = nodes[i] ? nodes[i].querySelector('select') : null;
       if (!sel || sel.selectedIndex < 0) { out.push(''); continue; }
       out.push($(sel.options[sel.selectedIndex]).text());
     }
     return out;
   };

   ext.order is the documented DataTables extension point for "user editable elements such as form inputs" (dt.js:14487), and the key is re-evaluated on every sort/draw, so it follows a live edit (onRoleChange re-syncs the cell data), the rows rebuilt by applyBulkRole() and any locale change — with no extra bookkeeping and no stale cached state.

Plan Role Override sorted ascending — the grid is grouped by the assigned role (<inherited> <no rights> → <inherited> admin → <inherited> guest → <inherited> leader → leader → senior tester → test designer), header showing sorting_asc:

Fixture tmp/fixtures_1670.php (re-run on every fresh DB): tproject SRT1670 (id 1), tplan SRT1670 Plan (id 2, + SRT1670 Plan B id 3), six users with distinct global roles and distinct plan-role assignments so the sort is observable — srt1670norights (inherited <no rights>), srt1670designer (test designer), srt1670guest (inherited guest), srt1670senior (senior tester), srt1670tester (leader), srt1670leader (inherited leader).

Full manual pass: tmp/TLU_Test_Cases.md — Suite 1670 — 14/14 PASS.

• #939 — DataTables pagination + "User" search for this screen (its columnDefs note is the one this issue corrects; its case "Sorting" only exercised the Login column).
• #930 — the identical grid features closed for the Assign Test Project Roles screen, which already kept the role column sortable.
• #1641 / #1642 — config-driven pagination and stateSave, separate legacy grid features.

Refs #1670.