feat: added rule based connection validation and connection limits to the editor

src/pages/VisProgPage/visualProgrammingUI/HandleRules.ts

@@ -0,0 +1,45 @@
+import {
+  type HandleRule,
+  ruleResult
+} from "./HandleRuleLogic.ts";
+import useFlowStore from "./VisProgStores.tsx";
+
+
+/**
+ * this specifies what types of nodes can make a connection to a handle that uses this rule
+ */
+export function allowOnlyConnectionsFromType(nodeTypes: string[]) : HandleRule  {
+  return ((_, {source}) => {
+    const sourceType = useFlowStore.getState().nodes.find(node => node.id === source.id)!.type!;
+    return nodeTypes.find(type => sourceType === type)
+      ? ruleResult.satisfied
+      : ruleResult.notSatisfied(`the target doesn't allow connections from nodes with type: ${sourceType}`);
+  })
+}
+
+/**
+ * similar to allowOnlyConnectionsFromType,
+ * this is a more specific variant that allows you to restrict connections to specific handles on each nodeType
+ */
+//
+export function allowOnlyConnectionsFromHandle(handles: {nodeType: string, handleId: string}[]) : HandleRule  {
+  return ((_, {source}) => {
+    const sourceNode = useFlowStore.getState().nodes.find(node => node.id === source.id)!;
+    return handles.find(handle => sourceNode.type === handle.nodeType && source.handleId === handle.handleId)
+      ? ruleResult.satisfied
+      : ruleResult.notSatisfied(`the target doesn't allow connections from nodes with type: ${sourceNode.type}`);
+  })
+}
+
+
+/**
+ * This rule prevents a node from making a connection between its own handles
+ */
+export const noSelfConnections : HandleRule =
+  (connection, _) => {
+    return connection.source !== connection.target
+      ? ruleResult.satisfied
+      : ruleResult.notSatisfied("nodes are not allowed to connect to themselves");
+  }
+
+