From 912e519954b9c10873b944ec6d94c6cdc948853e Mon Sep 17 00:00:00 2001
From: Joseph Doherty <dohejw01@gmail.com>
Date: Tue, 8 Sep 2026 01:15:40 -0400
Subject: [PATCH] =?UTF-8?q?fix(central-ui):=20ParameterValueForm=20?=
 =?UTF-8?q?=E2=80=94=20raise=20ValidChanged=20on=20schema=20set=20so=20req?=
 =?UTF-8?q?uired-field=20validity=20is=20never=20stale?=
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Claude-Session: https://claude.ai/code/session_01NcMG6xXdsJbmD2wYAgkK29
---
 .../Shared/ParameterValueForm.razor           | 38 +++++++++++++++++++
 .../Design/ParameterValueFormTests.cs         | 28 ++++++++++++++
 2 files changed, 66 insertions(+)

diff --git a/src/ZB.MOM.WW.ScadaBridge.CentralUI/Components/Shared/ParameterValueForm.razor b/src/ZB.MOM.WW.ScadaBridge.CentralUI/Components/Shared/ParameterValueForm.razor
index 5117bc64..0d1ab5f3 100644
--- a/src/ZB.MOM.WW.ScadaBridge.CentralUI/Components/Shared/ParameterValueForm.razor
+++ b/src/ZB.MOM.WW.ScadaBridge.CentralUI/Components/Shared/ParameterValueForm.razor
@@ -77,6 +77,44 @@ else
         _shapes = ScriptParameterNames.ParseShapes(ParameterDefinitions);
         _rootSchema = await ParseRootAsync();
         _topLevelFields = _rootSchema?.Type == "object" ? _rootSchema.Fields : Array.Empty<InboundApiSchemaField>();
+
+        // Report validity for the freshly-(re)parsed schema so a caller gating a Run
+        // button on ValidChanged never starts (or carries over from a prior script)
+        // a stale "valid" reading when required fields are unset. This deliberately
+        // does NOT call Validate()/populate _parseErrors: the component has no
+        // "untouched field" concept -- RenderError paints whatever is in
+        // _parseErrors unconditionally -- so doing that here would immediately
+        // paint every required field red before the user has touched anything. The
+        // silent check below computes the same answer without that side effect;
+        // _parseErrors (and the visible red text) still only appears once editing
+        // drives it through Emit()/Validate() as before.
+        await ValidChanged.InvokeAsync(ComputeIsValid());
+    }
+
+    // Mirrors Validate()'s schema pass (plus any raw-text parse markers already
+    // parked in _parseErrors) WITHOUT writing to _parseErrors, so it can run on
+    // every schema (re)parse without painting untouched required fields red.
+    private bool ComputeIsValid()
+    {
+        if (_parseErrors.Count > 0)
+        {
+            return false;
+        }
+        if (_rootSchema is null)
+        {
+            return true;
+        }
+        try
+        {
+            var element = JsonSerializer.SerializeToElement(Values);
+            var errors = new List<string>();
+            _rootSchema.Validate(element, string.Empty, errors);
+            return errors.Count == 0;
+        }
+        catch (JsonException)
+        {
+            return false;
+        }
     }
 
     /// <summary>
diff --git a/tests/ZB.MOM.WW.ScadaBridge.CentralUI.Tests/Design/ParameterValueFormTests.cs b/tests/ZB.MOM.WW.ScadaBridge.CentralUI.Tests/Design/ParameterValueFormTests.cs
index 023e2f0e..c7b1f419 100644
--- a/tests/ZB.MOM.WW.ScadaBridge.CentralUI.Tests/Design/ParameterValueFormTests.cs
+++ b/tests/ZB.MOM.WW.ScadaBridge.CentralUI.Tests/Design/ParameterValueFormTests.cs
@@ -297,4 +297,32 @@ public class ParameterValueFormTests : BunitContext
         input.Input("5");
         Assert.True(valid.Last());
     }
+
+    [Fact]
+    public void ValidChanged_ReportsFalseOnFirstRender_WhenARequiredFieldIsEmpty()
+    {
+        var valid = new List<bool>();
+        var cut = Render<ParameterValueForm>(p => p
+            .Add(x => x.ParameterDefinitions, """{"type":"object","properties":{"n":{"type":"integer"}},"required":["n"]}""")
+            .Add(x => x.ValidChanged, v => valid.Add(v)));
+
+        // Reported without any input from the user...
+        Assert.False(valid.Last());
+
+        // ...and no red error text is painted for the untouched required field (the
+        // component has no "untouched" concept, so the validity check for
+        // ValidChanged deliberately does not populate _parseErrors on first render).
+        Assert.Empty(cut.FindAll(".text-danger"));
+    }
+
+    [Fact]
+    public void ValidChanged_ReportsTrueOnFirstRender_WhenNothingIsRequired()
+    {
+        var valid = new List<bool>();
+        var cut = Render<ParameterValueForm>(p => p
+            .Add(x => x.ParameterDefinitions, """{"type":"object","properties":{"n":{"type":"integer"}}}""")
+            .Add(x => x.ValidChanged, v => valid.Add(v)));
+
+        Assert.True(valid.Last());
+    }
 }