From 240320696a928558ff3937515aa7e9a686bc6e0e Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Merlin=20Z=C3=B6bl?=
 <41567572+K0369@users.noreply.github.com>
Date: Mon, 16 Oct 2023 12:01:37 +0200
Subject: [PATCH 1/5] Adding check for target being a portModel

---
 site/Site/Components/Landing/LandingShowcaseDiagram.razor.cs | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/site/Site/Components/Landing/LandingShowcaseDiagram.razor.cs b/site/Site/Components/Landing/LandingShowcaseDiagram.razor.cs
index 835c8fdcd..2de170860 100644
--- a/site/Site/Components/Landing/LandingShowcaseDiagram.razor.cs
+++ b/site/Site/Components/Landing/LandingShowcaseDiagram.razor.cs
@@ -76,7 +76,7 @@ private void OnLinKTargetChanged(BaseLinkModel link, Anchor? oldTarget, Anchor?
     private void OnLinkRemoved(BaseLinkModel link)
     {
         (link.Source.Model as PortModel)!.Parent.Refresh();
-        if (link.Target != null) (link.Target.Model as PortModel)!.Parent.Refresh();
+        if (link.Target != null && link.Target.Model is PortModel portModel) portModel.Parent.Refresh();
         link.TargetChanged -= OnLinKTargetChanged;
     }
 }
\ No newline at end of file

From 93b154baa10ecc4e12c1ec1a60ac30475d393b74 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Merlin=20Z=C3=B6bl?=
 <41567572+K0369@users.noreply.github.com>
Date: Mon, 16 Oct 2023 12:02:50 +0200
Subject: [PATCH 2/5] Fixing nodes not updating on change of the link target

---
 site/Site/Components/Landing/LandingShowcaseDiagram.razor.cs | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/site/Site/Components/Landing/LandingShowcaseDiagram.razor.cs b/site/Site/Components/Landing/LandingShowcaseDiagram.razor.cs
index 2de170860..4e5717172 100644
--- a/site/Site/Components/Landing/LandingShowcaseDiagram.razor.cs
+++ b/site/Site/Components/Landing/LandingShowcaseDiagram.razor.cs
@@ -67,7 +67,7 @@ private void OnLinkAdded(BaseLinkModel link)
 
     private void OnLinKTargetChanged(BaseLinkModel link, Anchor? oldTarget, Anchor? newTarget)
     {
-        if (oldTarget == null && newTarget != null) // First attach
+        if (link.IsAttached && newTarget is not null)
         {
             (newTarget.Model as PortModel)!.Parent.Refresh();
         }

From ff0fd5a0d07021e5cf224a57659ebdf14a37cc72 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Merlin=20Z=C3=B6bl?=
 <41567572+K0369@users.noreply.github.com>
Date: Sun, 22 Oct 2023 13:53:58 +0200
Subject: [PATCH 3/5] fixing NRE of onLinkRemoved in landing showcase diagram

---
 site/Site/Components/Landing/LandingShowcaseDiagram.razor.cs | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/site/Site/Components/Landing/LandingShowcaseDiagram.razor.cs b/site/Site/Components/Landing/LandingShowcaseDiagram.razor.cs
index 4e5717172..c78b72851 100644
--- a/site/Site/Components/Landing/LandingShowcaseDiagram.razor.cs
+++ b/site/Site/Components/Landing/LandingShowcaseDiagram.razor.cs
@@ -76,7 +76,10 @@ private void OnLinKTargetChanged(BaseLinkModel link, Anchor? oldTarget, Anchor?
     private void OnLinkRemoved(BaseLinkModel link)
     {
         (link.Source.Model as PortModel)!.Parent.Refresh();
-        if (link.Target != null && link.Target.Model is PortModel portModel) portModel.Parent.Refresh();
+        if (link.Target is SinglePortAnchor anchor && anchor.Model is PortModel portModel)
+        {
+            portModel.Parent.Refresh();
+        }
         link.TargetChanged -= OnLinKTargetChanged;
     }
 }
\ No newline at end of file

From 95a9734b6a518c740114774041780da529a687fa Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Merlin=20Z=C3=B6bl?=
 <41567572+K0369@users.noreply.github.com>
Date: Sun, 22 Oct 2023 14:24:55 +0200
Subject: [PATCH 4/5] refactoring link target refreshing in landing showcase
 diagram

---
 .../Components/Landing/LandingShowcaseDiagram.razor.cs     | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/site/Site/Components/Landing/LandingShowcaseDiagram.razor.cs b/site/Site/Components/Landing/LandingShowcaseDiagram.razor.cs
index c78b72851..17ffd29ba 100644
--- a/site/Site/Components/Landing/LandingShowcaseDiagram.razor.cs
+++ b/site/Site/Components/Landing/LandingShowcaseDiagram.razor.cs
@@ -67,9 +67,12 @@ private void OnLinkAdded(BaseLinkModel link)
 
     private void OnLinKTargetChanged(BaseLinkModel link, Anchor? oldTarget, Anchor? newTarget)
     {
-        if (link.IsAttached && newTarget is not null)
+        // only refresh on the first time the link is attached
+        if (oldTarget is PositionAnchor 
+            && newTarget.Model is PortModel targetModel
+            && link.IsAttached)        
         {
-            (newTarget.Model as PortModel)!.Parent.Refresh();
+            targetModel.Parent.Refresh();
         }
     }
 

From f1032af5db2120ec9ffeee7845559f075f3d655b Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Merlin=20Z=C3=B6bl?=
 <41567572+K0369@users.noreply.github.com>
Date: Sun, 22 Oct 2023 14:27:04 +0200
Subject: [PATCH 5/5] Demo-site: changing signature of onChange to reflect
 actual values

---
 site/Site/Components/Landing/LandingShowcaseDiagram.razor.cs | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/site/Site/Components/Landing/LandingShowcaseDiagram.razor.cs b/site/Site/Components/Landing/LandingShowcaseDiagram.razor.cs
index 17ffd29ba..d2933a427 100644
--- a/site/Site/Components/Landing/LandingShowcaseDiagram.razor.cs
+++ b/site/Site/Components/Landing/LandingShowcaseDiagram.razor.cs
@@ -65,7 +65,7 @@ private void OnLinkAdded(BaseLinkModel link)
         link.TargetChanged += OnLinKTargetChanged;
     }
 
-    private void OnLinKTargetChanged(BaseLinkModel link, Anchor? oldTarget, Anchor? newTarget)
+    private void OnLinKTargetChanged(BaseLinkModel link, Anchor oldTarget, Anchor newTarget)
     {
         // only refresh on the first time the link is attached
         if (oldTarget is PositionAnchor