From 8ab520ef570741e5fc269036e35aa139e63a99c3 Mon Sep 17 00:00:00 2001
From: Joseph Doherty <dohejw01@gmail.com>
Date: Tue, 11 Aug 2026 06:06:49 -0400
Subject: [PATCH] fix(scripts): gate the source dialog's existence on the held
 id, not the resolve
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

The modal's existence was a function of _rows (FindSourceScript() as the
visibility gate), so any render where the row is momentarily unresolvable —
a future reload nulling or replacing the list — unmounts the subtree and
disposes the Close handler's binding id mid-click (GetRequiredEventBindingEntry).
Latent here (_rows is written once, in OnInitializedAsync) but the identical
shape bit ScadaBridge live the moment a page refresh landed, and it presents
as an unattributable intermittent once one does.

ScadaBridge's shape, ported by the family sweep: intent (_sourceScriptId)
gates existence, the resolve drives only content; an unresolvable script
renders a notice with the frame and Close still mounted, and closing remains
the operator's action rather than a side effect of list state.
---
 .../Components/Pages/Scripts.razor            | 34 +++++++++++++++----
 1 file changed, 28 insertions(+), 6 deletions(-)

diff --git a/src/Server/ZB.MOM.WW.OtOpcUa.AdminUI/Components/Pages/Scripts.razor b/src/Server/ZB.MOM.WW.OtOpcUa.AdminUI/Components/Pages/Scripts.razor
index 54130124..8f3612ac 100644
--- a/src/Server/ZB.MOM.WW.OtOpcUa.AdminUI/Components/Pages/Scripts.razor
+++ b/src/Server/ZB.MOM.WW.OtOpcUa.AdminUI/Components/Pages/Scripts.razor
@@ -60,21 +60,42 @@ else
     </section>
 }
 
-@if (FindSourceScript() is { } src)
+@* The dialog's EXISTENCE is gated on the held id (operator intent); the resolve drives only its
+   CONTENT. Gating existence on FindSourceScript() would make the modal a function of _rows, and any
+   render where the row is momentarily unresolvable (a future reload/poll setting _rows null or
+   replacing the list) would unmount the subtree and dispose the Close handler's binding id — a
+   click already in flight then throws GetRequiredEventBindingEntry. Latent today (_rows is written
+   once, in OnInitializedAsync) but the shape bit ScadaBridge live the moment a refresh landed. *@
+@if (_sourceScriptId is not null)
 {
+    var src = FindSourceScript();
     <div class="modal-backdrop fade show" style="display:block"></div>
     <div class="modal fade show" tabindex="-1" role="dialog" style="display:block">
         <div class="modal-dialog modal-lg modal-dialog-scrollable" role="document">
             <div class="modal-content">
                 <div class="modal-header">
                     <h5 class="modal-title">
-                        @(string.IsNullOrWhiteSpace(src.Name) ? src.ScriptId : src.Name)
-                        <span class="mono small text-muted ms-2">@src.ScriptId</span>
+                        @if (src is not null)
+                        {
+                            @(string.IsNullOrWhiteSpace(src.Name) ? src.ScriptId : src.Name)
+                            <span class="mono small text-muted ms-2">@src.ScriptId</span>
+                        }
+                        else
+                        {
+                            <span class="mono">@_sourceScriptId</span>
+                        }
                     </h5>
                     <button type="button" class="btn-close" aria-label="Close" @onclick="CloseSource"></button>
                 </div>
                 <div class="modal-body">
-                    <pre class="mono small mb-0" style="background:var(--zebra-bg);padding:1rem;border-radius:4px;overflow:auto">@src.SourceCode</pre>
+                    @if (src is not null)
+                    {
+                        <pre class="mono small mb-0" style="background:var(--zebra-bg);padding:1rem;border-radius:4px;overflow:auto">@src.SourceCode</pre>
+                    }
+                    else
+                    {
+                        <p class="text-muted mb-0">This script is no longer loaded.</p>
+                    }
                 </div>
                 <div class="modal-footer">
                     <button type="button" class="btn btn-outline-secondary" @onclick="CloseSource">Close</button>
@@ -99,8 +120,9 @@ else
             .ToListAsync();
     }
 
-    /// <summary>Re-resolves the open dialog's script from the current list on every render; a script
-    /// that is no longer loaded renders nothing, so the dialog self-closes.</summary>
+    /// <summary>Re-resolves the open dialog's script from the current list on every render. Drives
+    /// the dialog's CONTENT only — never its existence (see the comment at the markup): a script
+    /// that is no longer loaded renders a notice with the frame and Close still mounted.</summary>
     private Script? FindSourceScript()
         => _sourceScriptId is null
             ? null