From d74ac5f2bc32e691eda322264bab455a36a08dd9 Mon Sep 17 00:00:00 2001
From: josihoppe <116898820+josihoppe@users.noreply.github.com>
Date: Mon, 24 Nov 2025 16:51:51 +0100
Subject: [PATCH 1/2] added js check to see if the nodes are connected before
 saving

---
 app/static/js/grid_model_topology.js       | 41 ++++++++++++++++++++++
 app/templates/scenario/scenario_step2.html |  6 ++++
 2 files changed, 47 insertions(+)

diff --git a/app/static/js/grid_model_topology.js b/app/static/js/grid_model_topology.js
index 1571e8ef..27a75a0a 100644
--- a/app/static/js/grid_model_topology.js
+++ b/app/static/js/grid_model_topology.js
@@ -747,3 +747,44 @@ function computeCOP(event){
         alert(error.message);
     });
 }
+
+
+function validateNodeConnections(editor) {
+    const nodes = editor.export().drawflow.Home.data;
+
+    for (const nodeId in nodes) {
+        const node = nodes[nodeId];
+        const name = node.name; // "...-demand", "bus--...", sources are the rest
+        let inputCount = 0;
+        let outputCount = 0;
+
+        for (const inputName in node.inputs) {
+            inputCount += node.inputs[inputName].connections.length;
+        }
+        for (const outputName in node.outputs) {
+            outputCount += node.outputs[outputName].connections.length;
+        }
+        // Sink
+        if (name.endsWith("demand")) {
+            if (inputCount < 1) {
+                alert(`Sink "${node.data.name}" must have at least 1 input.`);
+                return false;
+            }
+            continue;
+        }
+        // Bus
+        if (name.startsWith("bus--")) {
+            if (inputCount < 1 || outputCount < 1) {
+                alert(`Bus "${node.data.name}" must have at least 1 input AND 1 output.`);
+                return false;
+            }
+            continue;
+        }
+        // Source
+        if (outputCount < 1) {
+            alert(`Source "${node.data.name}" must have at least 1 output.`);
+            return false;
+        }
+    }
+    return true;
+}
diff --git a/app/templates/scenario/scenario_step2.html b/app/templates/scenario/scenario_step2.html
index 2e13f706..6309246b 100644
--- a/app/templates/scenario/scenario_step2.html
+++ b/app/templates/scenario/scenario_step2.html
@@ -217,6 +217,12 @@ <h3>{{ group_names|get_item:group_name|title }}</h3>
         // warn in case of empty model
         if (node_list.length == 0 && !confirm('No components in model. Continue?'))
             return;
+        // Check that all nodes are connected to at least one bus
+        if (!validateNodeConnections(editor)) {
+            console.log("connections are false")
+            return;
+        }
+
         // Check if there are duplicate node names in the model
         // and prevent user from saving the model if there are.
         // Might also be handled in backend when saving names.

From cdc4440fd17243b8c5844a4f961fdc8511a44bf5 Mon Sep 17 00:00:00 2001
From: josihoppe <116898820+josihoppe@users.noreply.github.com>
Date: Tue, 9 Dec 2025 18:08:31 +0100
Subject: [PATCH 2/2] fixed check for busses, wrong naming convention used

---
 app/static/js/grid_model_topology.js | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/app/static/js/grid_model_topology.js b/app/static/js/grid_model_topology.js
index 27a75a0a..731f4663 100644
--- a/app/static/js/grid_model_topology.js
+++ b/app/static/js/grid_model_topology.js
@@ -773,7 +773,7 @@ function validateNodeConnections(editor) {
             continue;
         }
         // Bus
-        if (name.startsWith("bus--")) {
+        if (name.startsWith("bus")) {
             if (inputCount < 1 || outputCount < 1) {
                 alert(`Bus "${node.data.name}" must have at least 1 input AND 1 output.`);
                 return false;