diff --git a/src/components/util/format.js b/src/components/util/format.js
new file mode 100644
index 0000000..44e494d
--- /dev/null
+++ b/src/components/util/format.js
@@ -0,0 +1,3 @@
+export function formatLayerId (id) {
+  return id === "" ? "[empty_string]" : `'${id}'`;
+}