src/pages/VisProgPage/visualProgrammingUI/nodes/InferredBeliefNode.tsx

@@ -1,6 +1,7 @@
-import {getConnectedEdges, type Node, type NodeProps, Position} from '@xyflow/react';
+import {getConnectedEdges, type Node, type NodeProps, Position, useNodeConnections} from '@xyflow/react';
-import {useState} from "react";
+import {useEffect, useState} from "react";
 import styles from '../../VisProg.module.css';
+import type {EditorWarning} from "../components/EditorWarnings.tsx";
 import {Toolbar} from '../components/NodeComponents.tsx';
 import {MultiConnectionHandle, SingleConnectionHandle} from "../components/RuleBasedHandle.tsx";
 import {allowOnlyConnectionsFromType} from "../HandleRules.ts";
@@ -91,7 +92,7 @@ export const InferredBeliefTooltip = `
  */
 export default function InferredBeliefNode(props: NodeProps<InferredBeliefNode>) {
   const data = props.data;
-  const { updateNodeData } = useFlowStore();
+  const { updateNodeData, registerWarning, unregisterWarning } = useFlowStore();
   // start of as an AND operator, true: "AND", false: "OR"
   const [enforceAllBeliefs, setEnforceAllBeliefs] = useState(true);
 
@@ -109,6 +110,29 @@ export default function InferredBeliefNode(props: NodeProps<InferredBeliefNode>)
     });
   }
 
+  const beliefConnections = useNodeConnections({
+    id: props.id,
+    handleType: "target",
+  })
+
+  useEffect(() => {
+    const noBeliefsWarning : EditorWarning = {
+      scope: {
+        id: props.id,
+        handleId: undefined
+      },
+      type: 'MISSING_INPUT',
+      severity: 'ERROR',
+      description: `This AND/OR node is missing one or more beliefs, 
+      please make sure to use both inputs of an AND/OR node`
+    };
+
+    if (beliefConnections.length < 2){
+      registerWarning(noBeliefsWarning);
+      return;
+    }
+    unregisterWarning(props.id, noBeliefsWarning.type);
+  },[beliefConnections.length, props.id, registerWarning, unregisterWarning])
   return (
     <>
       <Toolbar nodeId={props.id} allowDelete={true}/>