From 5e1e6651bc768e387af5040361c5850c670e4f9e Mon Sep 17 00:00:00 2001
From: Devin Mullins <twifkak@google.com>
Date: Fri, 21 Oct 2022 11:44:44 -0700
Subject: [PATCH] Add options to modify URL and link element

---
 instantpage.js | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/instantpage.js b/instantpage.js
index ff14629..ec9b56d 100644
--- a/instantpage.js
+++ b/instantpage.js
@@ -232,6 +232,10 @@ function isPreloadable(linkElement) {
 }
 
 function preload(url) {
+  if (typeof instantUrlModifier === 'function') {
+    url = instantUrlModifier(url);
+  }
+
   if (prefetches.has(url)) {
     return
   }
@@ -239,6 +243,9 @@ function preload(url) {
   const prefetcher = document.createElement('link')
   prefetcher.rel = 'prefetch'
   prefetcher.href = url
+  if (typeof instantLinkModifier === 'function') {
+    instantLinkModifier(prefetcher);
+  }
   document.head.appendChild(prefetcher)
 
   prefetches.add(url)