static/js/update: Fix null check

Induce possible 301/307 (http -> https) on browsers that don't understand
caching

1 files changed, 13 insertions, 12 deletions

diff --git a/static/js/update.ts b/static/js/update.ts
index 1a3384f..aa4ba77 100644
--- a/static/js/update.ts
+++ b/static/js/update.ts
@@ -20,14 +20,14 @@
     const url = self.location.href.split("#")[0].split("?")[0];
 
     const indicator = document.querySelector("a[data-update]");
-    if (indicator.dataset.update === "refresh" || indicator === null) return;
+    if (indicator === null || indicator.dataset.update === "refresh") return;
     const anchor = indicator.cloneNode();
 
     fetch(url, "HEAD", function (request) {
       const local = document.querySelector('meta[name="last-modified"]').content || document.lastModified;
-      const remote = request.getResponseHeader("last-modified") || document.lastModified;
-      const modified = Date.parse(remote) > Date.parse(local);
-      const drift = Date.parse(remote) - Date.parse(local);
+      const remote = request.getResponseHeader("last-modified") || '';
+      const modified = Date.parse(remote || local) > Date.parse(local);
+      const drift = Date.parse(remote || local) - Date.parse(local);
 
       if (drift < 10000) return;
 
@@ -38,14 +38,15 @@
       }
 
       if (remote && modified) {
-        fetch(url, "GET");
-        indicator.href = url;
-        indicator.removeAttribute("id");
-        indicator.dataset.update = "refresh";
-        console.log("INFO: R: " + remote);
-        console.log("INFO: L: " + local);
-        console.log("INFO: D: " + drift);
-        console.log("INFO: M: " + modified);
+        fetch(url, "GET", function () {
+          indicator.href = url.replace(/^https:/, "http:");
+          indicator.removeAttribute("id");
+          indicator.dataset.update = "refresh";
+          console.log("INFO: R: " + remote);
+          console.log("INFO: L: " + local);
+          console.log("INFO: D: " + drift);
+          console.log("INFO: M: " + modified);
+        });
       }
     });
   }