Effective config: do-0x20-encode revert fix, validation UI, custom displays, option help

- Fix do-0x20-encode: clearing pending when toggling back to original (Disabled/Default) - Do0x20EncodeDisplay: uncheck uses pending.OldValue when present - EffectiveConfigFieldDisplay: use pending.OldValue as _valueAtActivation when re-entering with pending - Effective config: validation errors/warnings in toolbar and save modal, revert from modal - Custom displays: Do0x20EncodeDisplay (tri-state), KeyOnlyOrValueDisplay - ExplicitToggleState, config/apply support for do-0x20-encode, option help and tests
2026-10-21 19:32:35 +10:00 · 2026-03-08 12:52:46 +10:00
parent 6cf4c07695
commit a03e93bcd3
89 changed files with 2229 additions and 67 deletions
@@ -18,7 +18,7 @@
    }
    <EffectiveConfigToolbar ShowSearchBox="@ShowSearchBox" SearchTerm="@_searchTerm" SearchTermChanged="@OnSearchTermChanged"
        IsEditMode="@Session.IsEditMode" PendingChangesCount="@Session.PendingChanges.Count"
-        ValidationErrorCount="@_validationErrorCount" ValidationWarningCount="@_validationWarningCount"
+        ValidationSummary="@Session.GetValidationSummary()"
        AllSectionsExpanded="@_allSectionsExpanded"
        OnExpandAll="ExpandAll" OnCollapseAll="CollapseAll" OnEnterEditMode="EnterEditMode" OnExitEditModeWithConfirm="ExitEditModeWithConfirmAsync" OnOpenSaveModal="OpenSaveModal" />
    <CascadingValue Value="@Session">
@@ -28,7 +28,7 @@
    </CascadingValue>
    </CascadingValue>
    <EffectiveConfigSaveFlow ShowModal="@_showSaveModal" PendingChanges="@Session.PendingChanges" Status="@Status" Session="@Session"
-        OnClose="CloseSaveModal" OnSaveCompleted="OnSaveCompleted" OnContinueEditingAfterSavedFailure="ContinueEditingAfterSavedFailureAsync" OnCloseAndEndEdit="CloseSaveModalAndEndEdit" />
+        OnClose="CloseSaveModal" OnRevertedNotify="OnRevertedFromSaveModal" OnSaveCompleted="OnSaveCompleted" OnContinueEditingAfterSavedFailure="ContinueEditingAfterSavedFailureAsync" OnCloseAndEndEdit="CloseSaveModalAndEndEdit" />
 </div>
 }

@@ -42,9 +42,6 @@
    private HashSet<string> _openPanels = new();
    private bool _showSaveModal;

-    private int _validationErrorCount => Session.GetValidationSummary().Count(i => i.Severity == FieldIssueSeverity.Error);
-    private int _validationWarningCount => Session.GetValidationSummary().Count(i => i.Severity == FieldIssueSeverity.Warning);
-
    private string? _optionHelpKey;
    private string? _optionHelpAnchorId;
    private string _optionHelpTitle = "Option help";
@@ -199,6 +196,12 @@
        Session.SetCrossOptionIssues(issues);
    }

+    private void OnRevertedFromSaveModal()
+    {
+        RunCrossOptionEvaluator();
+        StateHasChanged();
+    }
+
    private void OpenSaveModal()
    {
        if (Session.PendingChanges.Count == 0) return;
@@ -187,11 +187,23 @@
    gap: 0.25rem;
 }

-/* Edit wrapper (checkbox/input) shrinks to content so the editable badge stays on the same line */
+/* When a field is active: value + badges in one block so any click inside (checkbox, input, ok/cancel) doesn't deactivate */
+::deep .ec-field-value-when-editing {
+    display: inline-flex;
+    flex-wrap: wrap;
+    align-items: center;
+    gap: 0.25rem;
+    min-width: 0;
+    max-width: 100%;
+}
+
+/* Edit wrapper (checkbox/input) shrinks to content */
 ::deep .ec-field-edit-wrapper {
-    flex: 0 0 auto;
+    flex: 0 1 auto;
    display: inline-flex;
    align-items: center;
+    min-width: 0;
+    max-width: 100%;
 }

 /* Input/select in value area can shrink so the editable badge stays on the same line */
@@ -253,6 +265,21 @@
    line-height: 1;
 }

+/* Only when field is in edit mode: push ok/cancel/revert to end and allow them to wrap first on narrow widths */
+::deep .ec-field-value-when-editing > .status-badge-inline {
+    flex: 0 0 auto;
+    white-space: nowrap;
+    margin-left: auto;
+}
+
+@media (max-width: 991.98px) {
+    ::deep .ec-field-value-when-editing > .status-badge-inline {
+        flex-basis: 100%;
+        margin-left: 0;
+        margin-top: 0.15rem;
+    }
+}
+
@media (max-width: 767.98px) {
    ::deep .ec-section-header {
        padding-left: 0.75rem;
@@ -35,12 +35,24 @@
                <span class="small ec-toolbar-validation-count" aria-live="polite">
                    @if (ValidationErrorCount > 0)
                    {
-                        <span class="text-danger fw-medium">errors: @ValidationErrorCount</span>
+                        <span class="text-danger fw-medium ec-toolbar-changes-link" role="button" tabindex="0"
+                              title="@ValidationErrorTooltip"
+                              aria-label="Open save dialog"
+                              @onclick="OnOpenSaveModal"
+                              @onkeydown="OnValidationLinkKeyDown">
+                            @ValidationErrorCount error(s)
+                        </span>
                    }
                    @if (ValidationErrorCount > 0 && ValidationWarningCount > 0) { <span class="text-muted">·</span> }
                    @if (ValidationWarningCount > 0)
                    {
-                        <span class="text-warning">warnings: @ValidationWarningCount</span>
+                        <span class="text-warning ec-toolbar-changes-link" role="button" tabindex="0"
+                              title="@ValidationWarningTooltip"
+                              aria-label="Open save dialog"
+                              @onclick="OnOpenSaveModal"
+                              @onkeydown="OnValidationLinkKeyDown">
+                            @ValidationWarningCount warning(s)
+                        </span>
                    }
                </span>
            }
@@ -60,8 +72,11 @@
    [Parameter] public EventCallback<string> SearchTermChanged { get; set; }
    [Parameter] public bool IsEditMode { get; set; }
    [Parameter] public int PendingChangesCount { get; set; }
-    [Parameter] public int ValidationErrorCount { get; set; }
-    [Parameter] public int ValidationWarningCount { get; set; }
+    [Parameter] public IReadOnlyList<FieldIssue>? ValidationSummary { get; set; }
+    private int ValidationErrorCount => ValidationSummary?.Count(i => i.Severity == FieldIssueSeverity.Error) ?? 0;
+    private int ValidationWarningCount => ValidationSummary?.Count(i => i.Severity == FieldIssueSeverity.Warning) ?? 0;
+    private string ValidationErrorTooltip => ValidationSummary == null ? "" : string.Join("\n", ValidationSummary.Where(i => i.Severity == FieldIssueSeverity.Error).Select(i => i.Message));
+    private string ValidationWarningTooltip => ValidationSummary == null ? "" : string.Join("\n", ValidationSummary.Where(i => i.Severity == FieldIssueSeverity.Warning).Select(i => i.Message));
    [Parameter] public bool AllSectionsExpanded { get; set; }
    [Parameter] public EventCallback OnExpandAll { get; set; }
    [Parameter] public EventCallback OnCollapseAll { get; set; }
@@ -85,8 +100,12 @@
    private async Task OnChangesLinkKeyDown(KeyboardEventArgs e)
    {
        if (e.Key == "Enter" || e.Key == " ")
-        {
            await OnOpenSaveModal.InvokeAsync();
-        }
+    }
+
+    private async Task OnValidationLinkKeyDown(KeyboardEventArgs e)
+    {
+        if (e.Key == "Enter" || e.Key == " ")
+            await OnOpenSaveModal.InvokeAsync();
    }
 }
@@ -0,0 +1,59 @@
+@namespace DnsmasqWebUI.Components.EffectiveConfig.CustomDisplays
+@using DnsmasqWebUI.Models.Dnsmasq
+@using DnsmasqWebUI.Models.Dnsmasq.EffectiveConfig
+@inherits EffectiveConfigValueDisplayBase
+
+@* do-0x20-encode / no-0x20-encode: tri-state. Checkbox shows Enabled vs not-Enabled; uncheck maps back to Default when that was the value at activation, else Disabled. *@
+@if (IsActiveEditor && Descriptor.GetSource()?.IsReadOnly != true)
+{
+    var isOn = GetState() == ExplicitToggleState.Enabled;
+    <input type="checkbox" class="form-check-input" checked="@isOn" @onchange="OnCheckedChange" @onfocusout="OnCommitRequested" />
+}
+else
+{
+    @(GetState() == ExplicitToggleState.Enabled ? "Enabled" : "Disabled")
+}
+
+@code {
+    private ExplicitToggleState _stateAtActivation;
+    private bool _wasActiveEditor;
+
+    private ExplicitToggleState GetState()
+    {
+        var v = GetEffectiveDisplayValue();
+        if (v is ExplicitToggleState s) return s;
+        return ExplicitToggleState.Default;
+    }
+
+    protected override void OnParametersSet()
+    {
+        if (!IsActiveEditor)
+            _stateAtActivation = GetState();
+        else if (!_wasActiveEditor)
+            _stateAtActivation = GetState();
+        _wasActiveEditor = IsActiveEditor;
+    }
+
+    private async Task OnCheckedChange(ChangeEventArgs e)
+    {
+        var isChecked = e.Value is true;
+        if (isChecked)
+        {
+            await NotifyValueChanged(ExplicitToggleState.Enabled);
+            return;
+        }
+
+        var pending = Session?.PendingChanges.FirstOrDefault(c =>
+            string.Equals(c.SectionId, Descriptor.SectionId, StringComparison.OrdinalIgnoreCase) &&
+            string.Equals(c.OptionName, Descriptor.OptionName, StringComparison.OrdinalIgnoreCase));
+        if (pending?.OldValue is ExplicitToggleState previousState)
+        {
+            await NotifyValueChanged(previousState);
+            return;
+        }
+
+        // No existing pending edit for this field: map unchecked based on the state at activation.
+        // Default and Disabled both display as "Disabled" in view mode, so we preserve true intent here.
+        await NotifyValueChanged(_stateAtActivation == ExplicitToggleState.Default ? ExplicitToggleState.Default : ExplicitToggleState.Disabled);
+    }
+}
@@ -0,0 +1,84 @@
+@namespace DnsmasqWebUI.Components.EffectiveConfig.CustomDisplays
+@using DnsmasqWebUI.Models.Dnsmasq
+@inherits EffectiveConfigValueDisplayBase
+
+@* Options that can be: not set, key-only (e.g. use-stale-cache), or key=value (e.g. use-stale-cache=60). Checkbox to enable; when enabled, optional value input. *@
+@if (IsActiveEditor && Descriptor.GetSource()?.IsReadOnly != true)
+{
+    var isEnabled = _editorValue != null;
+    var valuePart = _editorValue is { Length: > 0 } ? _editorValue : "";
+    <div class="ec-key-only-or-value-editor">
+        <div class="form-check form-switch mb-0 ec-key-only-or-value-switch">
+            <input type="checkbox"
+                   class="form-check-input"
+                   checked="@isEnabled"
+                   aria-label="Enable @Descriptor.OptionName"
+                   title="Set @Descriptor.OptionName"
+                   @onchange="OnCheckedChange" />
+        </div>
+        @if (isEnabled)
+        {
+            <input type="text"
+                   class="form-control form-control-sm ec-key-only-or-value-input"
+                   placeholder="Optional value"
+                   value="@valuePart"
+                   @oninput="OnValueInput" />
+        }
+    </div>
+}
+else
+{
+    var v = GetEffectiveDisplayValue() as string;
+    if (v is null)
+    {
+        @("(not set)")
+    }
+    else if (v.Length == 0)
+    {
+        @("Enabled")
+    }
+    else
+    {
+        @v
+    }
+}
+
+@code {
+    private string? _editorValue;
+    private bool _wasActiveEditor;
+
+    protected override void OnParametersSet()
+    {
+        var effective = GetEffectiveDisplayValue() as string;
+        if (!IsActiveEditor)
+        {
+            _editorValue = effective;
+        }
+        else if (!_wasActiveEditor)
+        {
+            _editorValue = effective;
+        }
+
+        _wasActiveEditor = IsActiveEditor;
+    }
+
+    private async Task OnCheckedChange(ChangeEventArgs e)
+    {
+        var isChecked = e.Value switch
+        {
+            bool b => b,
+            string s when bool.TryParse(s, out var parsed) => parsed,
+            _ => false
+        };
+
+        _editorValue = isChecked ? "" : null;
+        await NotifyValueChanged(_editorValue);
+    }
+
+    private async Task OnValueInput(ChangeEventArgs e)
+    {
+        var raw = e.Value?.ToString()?.Trim();
+        _editorValue = string.IsNullOrEmpty(raw) ? "" : raw;
+        await NotifyValueChanged(_editorValue);
+    }
+}
@@ -0,0 +1,31 @@
+.ec-key-only-or-value-editor {
+    display: inline-flex;
+    align-items: center;
+    gap: 0.5rem;
+    min-width: 0;
+    max-width: 100%;
+    white-space: nowrap;
+}
+
+.ec-key-only-or-value-switch {
+    display: inline-flex;
+    align-items: center;
+    flex: 0 0 auto;
+    min-height: 1.25rem;
+    padding-left: 0;
+}
+
+.ec-key-only-or-value-switch .form-check-input {
+    float: none;
+    margin: 0;
+    cursor: pointer;
+    position: relative;
+    top: 2px;
+}
+
+.ec-key-only-or-value-input {
+    flex: 1 1 7rem;
+    min-width: 0;
+    width: 7rem;
+    max-width: 9rem;
+}
@@ -22,12 +22,15 @@
        <span class="ec-field-value">
            @if (isActiveEditor)
            {
-                <div class="ec-field-edit-wrapper" @onfocusout="OnBlur" @onclick:stopPropagation="true">
-                    <CascadingValue Value="@true">
-                        <CascadingValue Value="@(EventCallback.Factory.Create<FocusEventArgs>(this, OnBlur))">
-                            @((fragmentWithCallback ?? fragment)(Descriptor))
+                <div class="ec-field-value-when-editing" @onclick:stopPropagation="true">
+                    <div class="ec-field-edit-wrapper">
+                        <CascadingValue Value="@true">
+                            <CascadingValue Value="@(EventCallback.Factory.Create<FocusEventArgs>(this, OnBlur))">
+                                @((fragmentWithCallback ?? fragment)(Descriptor))
+                            </CascadingValue>
                        </CascadingValue>
-                    </CascadingValue>
+                    </div>
+                    <OptionStateBadge AnchorId="@_readonlyBadgeAnchorId" Source="@Descriptor.GetSource()" OptionName="@Descriptor.OptionName" Value="@effectiveValue" IsInteractive="@IsEditMode" ShowEditableBadge="@showEditableBadge" HasPendingChange="@_hasPendingChange" EditableAsButton="true" FieldKey="@FieldKey" IsActiveEditor="@isActiveEditor" OnConfirmRequested="@HandleConfirmEdit" OnCancelRequested="@HandleCancelEdit" OnRevertRequested="@HandleRevertEdit" />
                </div>
            }
            else
@@ -35,8 +38,8 @@
                <CascadingValue Value="@false">
                    @fragment(Descriptor)
                </CascadingValue>
+                <OptionStateBadge AnchorId="@_readonlyBadgeAnchorId" Source="@Descriptor.GetSource()" OptionName="@Descriptor.OptionName" Value="@effectiveValue" IsInteractive="@IsEditMode" ShowEditableBadge="@showEditableBadge" HasPendingChange="@_hasPendingChange" EditableAsButton="true" FieldKey="@FieldKey" IsActiveEditor="@isActiveEditor" OnConfirmRequested="@HandleConfirmEdit" OnCancelRequested="@HandleCancelEdit" OnRevertRequested="@HandleRevertEdit" />
            }
-            <OptionStateBadge AnchorId="@_readonlyBadgeAnchorId" Source="@Descriptor.GetSource()" OptionName="@Descriptor.OptionName" Value="@effectiveValue" IsInteractive="@IsEditMode" ShowEditableBadge="@showEditableBadge" HasPendingChange="@_hasPendingChange" EditableAsButton="true" FieldKey="@FieldKey" IsActiveEditor="@isActiveEditor" OnConfirmRequested="@HandleConfirmEdit" OnCancelRequested="@HandleCancelEdit" OnRevertRequested="@HandleRevertEdit" />
        </span>
    </li>
 }
@@ -111,6 +114,7 @@ else
    private bool _hasPendingChange;
    private object? _valueAtActivation;
    private object? _draftValue;
+    private bool _hasDraftValue;
    private bool _wasActive;
    private ExitAction _exitAction = ExitAction.None;

@@ -140,7 +144,12 @@ else
        if (Descriptor.IsMultiValue)
            ComputeMultiValueState(Descriptor.GetItems(), pending?.NewValue as IReadOnlyList<string>, _draftValue as IReadOnlyList<string>);
        if (!_wasActive && IsActive)
-            _valueAtActivation = descriptorValue;
+        {
+            // Use pending.OldValue when present so "revert to original" clears the pending change (e.g. do-0x20-encode: Disabled → Enable → Disable).
+            _valueAtActivation = pending != null ? pending.OldValue : descriptorValue;
+            _hasDraftValue = false;
+            _draftValue = null;
+        }
        if (_wasActive && !IsActive && _exitAction == ExitAction.None)
            _ = InvokeAsync(CommitIfChangedAsync);
        if (_wasActive && !IsActive)
@@ -190,8 +199,7 @@ else
    private void HandleValueChanged(object? value)
    {
        _draftValue = value;
-        if (_hasPendingChange && ValuesEqual(_valueAtActivation, value))
-            _ = InvokeAsync(CommitIfChangedAsync);
+        _hasDraftValue = true;
    }

    private async Task OnBlur(FocusEventArgs _)
@@ -202,10 +210,11 @@ else

    private async Task<bool> CommitIfChangedAsync()
    {
-        var newValue = _draftValue ?? _effectiveValue;
+        var newValue = _hasDraftValue ? _draftValue : _effectiveValue;
        if (ValuesEqual(_valueAtActivation, newValue))
        {
            _draftValue = null;
+            _hasDraftValue = false;
            if (_hasPendingChange && Ui?.RevertFieldAsync != null)
                await Ui.RevertFieldAsync(Descriptor.SectionId, Descriptor.OptionName);
            return true;
@@ -228,6 +237,7 @@ else
        if (Ui != null)
            await Ui.CommitFieldAsync(args);
        _draftValue = null;
+        _hasDraftValue = false;
        return true;
    }

@@ -236,12 +246,14 @@ else
    private void HandleDefaultValueChanged(string value)
    {
        _draftValue = value;
+        _hasDraftValue = true;
    }

    private async Task HandleDefaultBlur(string? value)
    {
        if (!IsActive) return;
        _draftValue = value;
+        _hasDraftValue = true;
        if (!await CommitIfChangedAsync() && Ui != null)
            await Ui.ActivateFieldAsync(FieldKey);
    }
@@ -249,6 +261,7 @@ else
    private void HandleMultiValueChanged(IReadOnlyList<string> values)
    {
        _draftValue = values.ToList();
+        _hasDraftValue = true;
        if (Descriptor.IsMultiValue)
            ComputeMultiValueState(Descriptor.GetItems(), _effectiveValue as IReadOnlyList<string>, _draftValue as IReadOnlyList<string>);
        StateHasChanged();
@@ -266,6 +279,7 @@ else
    private async Task HandleCancelEdit()
    {
        _draftValue = null;
+        _hasDraftValue = false;
        _exitAction = ExitAction.Cancel;
        if (Ui != null)
            await Ui.DeactivateFieldAsync();
@@ -274,6 +288,7 @@ else
    private async Task HandleRevertEdit()
    {
        _draftValue = null;
+        _hasDraftValue = false;
        Session?.RevertChange(Descriptor.SectionId, Descriptor.OptionName);
        _exitAction = ExitAction.Revert;
        if (Ui != null)
@@ -39,6 +39,8 @@
    [Parameter] public IReadOnlyList<PendingEffectiveConfigChange> PendingChanges { get; set; } = null!;
    [Parameter] public DnsmasqServiceStatus? Status { get; set; }
    [Parameter] public EventCallback OnClose { get; set; }
+    /// <summary>Invoked when the modal reverts a change so the parent can re-run validation (e.g. cross-option evaluator).</summary>
+    [Parameter] public EventCallback OnRevertedNotify { get; set; }
    [Parameter] public EventCallback OnSaveCompleted { get; set; }
    [Parameter] public EventCallback OnContinueEditingAfterSavedFailure { get; set; }
    [Parameter] public EventCallback OnCloseAndEndEdit { get; set; }
@@ -60,6 +62,8 @@

    private async Task HandleReverted()
    {
+        if (OnRevertedNotify.HasDelegate)
+            await OnRevertedNotify.InvokeAsync();
        await InvokeAsync(StateHasChanged);
    }

@@ -2,6 +2,7 @@
@using DnsmasqWebUI.Models.Dnsmasq
@using DnsmasqWebUI.Models.Dnsmasq.EffectiveConfig
@using DnsmasqWebUI.Infrastructure.Services.EffectiveConfig.Abstractions
+@using DnsmasqWebUI.Infrastructure.Helpers.Config

 <div class="modal fade show" style="display: block;" tabindex="-1" role="dialog" aria-labelledby="ec-save-modal-title" aria-modal="true">
    <div class="modal-dialog modal-dialog-scrollable" role="document">
@@ -85,6 +86,35 @@
                }
                else
                {
+                    @if (ValidationErrors.Count > 0 || ValidationWarnings.Count > 0)
+                    {
+                        <div class="ec-save-modal-validation mb-3">
+                            @if (ValidationErrors.Count > 0)
+                            {
+                                <div class="alert alert-danger py-2 mb-2">
+                                    <strong>Validation errors</strong>
+                                    <ul class="mb-0 mt-1 ps-3">
+                                        @foreach (var issue in ValidationErrors)
+                                        {
+                                            <li>@issue.Message</li>
+                                        }
+                                    </ul>
+                                </div>
+                            }
+                            @if (ValidationWarnings.Count > 0)
+                            {
+                                <div class="alert alert-warning py-2 mb-2">
+                                    <strong>Validation warnings</strong>
+                                    <ul class="mb-0 mt-1 ps-3">
+                                        @foreach (var issue in ValidationWarnings)
+                                        {
+                                            <li>@issue.Message</li>
+                                        }
+                                    </ul>
+                                </div>
+                            }
+                        </div>
+                    }
                    <p class="text-muted mb-3">These changes will be written to your config. Remove any you don't want to keep.</p>
                    @if (ManagedFilePath != null)
                    {
@@ -114,9 +144,9 @@
                                            @if (!isMultiValue)
                                            {
                                                <span class="ec-save-modal-diff text-body">
-                                                    <span class="text-muted text-decoration-line-through">@FormatValue(change.OldValue)</span>
+                                                    <span class="text-muted text-decoration-line-through">@FormatValue(change.OldValue, change.OptionName)</span>
                                                    <span class="text-muted mx-1" aria-hidden="true">→</span>
-                                                    <span>@FormatValue(change.NewValue)</span>
+                                                    <span>@FormatValue(change.NewValue, change.OptionName)</span>
                                                </span>
                                            }
                                        </div>
@@ -180,7 +210,7 @@
                else if (SaveState != EffectiveConfigSaveFlow.SaveUiState.Saving && SaveState != EffectiveConfigSaveFlow.SaveUiState.RestoreInProgress)
                {
                    <button type="button" class="btn btn-secondary" @onclick="Close"><i class="bi bi-x me-1" aria-hidden="true"></i>Cancel</button>
-                    <button type="button" class="btn btn-primary" @onclick="Save" disabled="@(PendingChanges.Count == 0)"><i class="bi bi-floppy-fill me-1" aria-hidden="true"></i>Save</button>
+                    <button type="button" class="btn btn-primary" @onclick="Save" disabled="@(PendingChanges.Count == 0 || HasBlockingValidationErrors)"><i class="bi bi-floppy-fill me-1" aria-hidden="true"></i>Save</button>
                }
            </div>
        </div>
@@ -206,6 +236,10 @@

    private string? ManagedFilePath => Status?.ManagedFilePath;

+    private IReadOnlyList<FieldIssue> ValidationErrors => Session.GetValidationSummary().Where(i => i.Severity == FieldIssueSeverity.Error).ToList();
+    private IReadOnlyList<FieldIssue> ValidationWarnings => Session.GetValidationSummary().Where(i => i.Severity == FieldIssueSeverity.Warning).ToList();
+    private bool HasBlockingValidationErrors => Session.HasBlockingValidationErrors();
+
    private static string GetValidationFailedOutput(EffectiveConfigSaveResult result)
    {
        var err = (result.ValidationStdErr ?? "").Trim();
@@ -248,8 +282,10 @@
        return null;
    }

-    private static string FormatValue(object? v)
+    private static string FormatValue(object? v, string? optionName = null)
    {
+        if (optionName != null && EffectiveConfigWriteBehaviorMap.GetBehavior(optionName) == EffectiveConfigWriteBehavior.KeyOnlyOrValue)
+            return FormatKeyOnlyOrValue(v);
        if (v == null) return "(not set)";
        if (v is bool b) return b ? "on" : "off";
        var list = AsStringList(v);
@@ -257,6 +293,14 @@
        return v.ToString() ?? "(not set)";
    }

+    private static string FormatKeyOnlyOrValue(object? v)
+    {
+        if (v == null) return "(not set)";
+        var s = v.ToString();
+        if (string.IsNullOrEmpty(s)) return "(set)";
+        return s;
+    }
+
    private async Task Revert(PendingEffectiveConfigChange change)
    {
        Session.RevertChange(change.SectionId, change.OptionName);