static/js/update: Handle more drift

Make a bit smarter

1 files changed, 28 insertions, 10 deletions

diff --git a/assets/js/index.js b/assets/js/index.js
index 4268a24..3a0bdf6 100644
--- a/assets/js/index.js
+++ b/assets/js/index.js
@@ -109,21 +109,20 @@
     }
     function update() {
         const url = self.location.href.split("#")[0].split("?")[0];
+        const indicator = document.querySelector("a[data-update]");
+        if (indicator.dataset.update === "refresh" || indicator === null) return;
+        indicator.cloneNode();
         fetch(url, "HEAD", function(request) {
-            const local = document.querySelector('meta[name="last-modified"]').content;
-            const remote = request.getResponseHeader("last-modified") || '';
-            const modified = Date.parse(document.lastModified) !== Date.parse(remote);
-            const drift = Date.parse(remote || local) - Date.parse(local);
-            let indicator = document.querySelector("a[data-update]");
-            if (indicator === null) return;
-            indicator.cloneNode();
-            if (drift === 0) return;
+            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);
+            if (drift < 3000) return;
             if (remote && modified) {
                 fetch(url, "GET");
                 indicator.href = url;
                 indicator.removeAttribute("id");
                 indicator.dataset.update = "refresh";
-                self.removeEventListener("blur", update);
                 console.log("INFO: R: " + remote);
                 console.log("INFO: L: " + local);
                 console.log("INFO: D: " + drift);
@@ -131,7 +130,26 @@
             }
         });
     }
-    self.addEventListener("blur", update);
+    let scrolled;
+    let delay = 1000;
+    let delayed = 0;
+    self.addEventListener("scroll", function() {
+        if (scrolled) clearTimeout(scrolled);
+        scrolled = setTimeout(function() {
+            update();
+            delay = delay + delayed;
+            delayed = delay - delayed;
+        }, delay);
+    });
+    [
+        "focus",
+        "load",
+        "URLChangedCustomEvent"
+    ].forEach(function(event) {
+        self.addEventListener(event, function() {
+            update();
+        });
+    });
 })();
 (function() {
     const options = "targetWindow,width=700,height=500,toolbar=no,location=no,status=no,menubar=no,scrollbars=yes,resizable=yes";