feat: completed backend code for oidc permission inject

backend/src/lib/template/dot-access.ts

@@ -0,0 +1,34 @@
+/**
+ * Safely retrieves a value from a nested object using dot notation path
+ */
+export const getStringValueByDot = (
+  obj: Record<string, unknown> | null | undefined,
+  path: string,
+  defaultValue?: string
+): string | undefined => {
+  // Handle null or undefined input
+  if (!obj) {
+    return defaultValue;
+  }
+
+  const parts = path.split(".");
+  let current: unknown = obj;
+
+  for (const part of parts) {
+    const isObject = typeof current === "object" && !Array.isArray(current) && current !== null;
+    if (!isObject) {
+      return defaultValue;
+    }
+    if (!Object.hasOwn(current as object, part)) {
+      // Check if the property exists as an own property
+      return defaultValue;
+    }
+    current = (current as Record<string, unknown>)[part];
+  }
+
+  if (typeof current !== "string") {
+    return defaultValue;
+  }
+
+  return current;
+};