1 files changed, 38 insertions, 0 deletions
diff --git a/demo/static/htmp.js b/demo/static/htmp.js
new file mode 100644
index 0000000..27d963b
--- /dev/null
+++ b/demo/static/htmp.js
@@ -0,0 +1,38 @@
+const iframe = document.createElement("iframe");
+iframe.name = "htmp";
+iframe.hidden = true;
+iframe.addEventListener("load", function () {
+  setTimeout(() => {
+    const cd = this.contentDocument;
+    const cw = this.contentWindow;
+    // If the server responds with an entire HTML document, replace the current document with it.
+    // To check whether the response is an entire page we check the presence of this very snippet.
+    if (cd.querySelector("iframe[name='htmp']")) {
+      document.documentElement.replaceWith(cd.documentElement);
+      // If the server responds with a fragment, replace the target element with it.
+    } else {
+      document
+        .querySelector(cw.location.hash || null)
+        ?.replaceWith(...cd.body.childNodes);
+      const url = new URL(cw.location.href);
+      url.searchParams.delete("htmp");
+      url.hash = "";
+      history.replaceState({}, "", url.toString());
+    }
+  });
+});
+document.body.appendChild(iframe);
+
+document.querySelectorAll("form[htmp]").forEach(function (el) {
+  const r = el.attributes.replace.value;
+  const input = document.createElement("input");
+  input.type = "hidden";
+  input.name = "htmp";
+  input.value = r;
+  el.appendChild(input);
+
+  const action = new URL(el.action);
+  action.hash = r;
+  el.action = action.toString();
+  el.target = "htmp";
+});