feat(runtime): add URL-state GET navigation

hemx-js/runtime/hemx.js

@@ -190,6 +190,36 @@
     return url.href;
   }
 
+  function pageRequestUrl(form, source) {
+    const url = new URL((form && form.action) || location.href, location.href);
+    url.search = urlEncoded(successfulFormData(form, source)).toString();
+    return url.href;
+  }
+
+  function successfulFormData(form, source) {
+    try {
+      return source && source !== form ? new FormData(form, source) : new FormData(form);
+    } catch (_) {
+      return new FormData(form);
+    }
+  }
+
+  function pageFormHistoryMode(source, form) {
+    return historyMode(source, null) || historyMode(form, null) || historyMode(boostRoot(form), null);
+  }
+
+  function boostRoot(el) {
+    return el && closestInRoot(el.parentElement, rootOf(el), (node) => node.hasAttribute("data-hemx-boost"));
+  }
+
+  function historyMode(el, fallback) {
+    if (!el) return fallback;
+    const value = el.getAttribute("data-hemx-history") || el.getAttribute("data-hemx-nav") || "";
+    if (value === "push" || value === "replace" || value === "none") return value;
+    if (el.hasAttribute("data-hemx-history") || el.hasAttribute("data-hemx-nav")) return fallback || "push";
+    return fallback;
+  }
+
   function httpError(response) {
     const error = new Error(`HTTP ${response.status}`);
     error.status = response.status;
@@ -233,6 +263,7 @@
     let finish;
     const done = new Promise((resolve) => { finish = resolve; });
     const method = String((form && form.getAttribute("method")) || "POST").toUpperCase();
+    const mode = method === "GET" && form && pageFormHistoryMode(source, form);
     const body = method === "GET" || method === "HEAD" ? undefined : requestBody(data, multipart);
     const headers = { "X-HEMX-Partial": "1", "Accept": "application/hemx, text/html" };
     if (body instanceof URLSearchParams) headers["Content-Type"] = "application/x-www-form-urlencoded;charset=UTF-8";
@@ -240,6 +271,10 @@
     showError(target, null);
     showPending(target, true);
     try {
+      if (mode) {
+        await navigateUrl(pageRequestUrl(form, source), rootOf(form) || rootOf(el), mode);
+        return;
+      }
       const response = await fetch(requestUrl(form, data, method), {
         method,
         body,
@@ -629,7 +664,7 @@
         );
         if (name === "click" && nav && sameOriginNav(event, nav)) {
           event.preventDefault();
-          navigate(nav);
+          navigate(nav, historyMode(nav, "push"));
           return;
         }
         if (name === "click") {
@@ -646,7 +681,7 @@
             (el.tagName === "INPUT" && el.getAttribute("type") === "submit")
           );
           const form = formOwner(submitter);
-          if (form && root.contains(form) && formHandleId(form)) {
+          if (form && root.contains(form) && (formHandleId(form) || pageFormHistoryMode(submitter, form))) {
             if (form.reportValidity && !form.reportValidity()) return;
             event.preventDefault();
             schedule(form, "submit", submitter);
@@ -655,9 +690,9 @@
         }
         let el = closestInRoot(event.target, root, (node) =>
           node.hasAttribute(HID) ||
-          (node.tagName === "FORM" && closestInRoot(node.parentElement, root, (parent) => parent.hasAttribute("data-hemx-boost")))
+          (node.tagName === "FORM" && (pageFormHistoryMode(event.submitter || node, node) || boostRoot(node)))
         );
-        if (name === "submit" && !el && event.target && event.target.tagName === "FORM" && formHandleId(event.target)) el = event.target;
+        if (name === "submit" && !el && event.target && event.target.tagName === "FORM" && (formHandleId(event.target) || pageFormHistoryMode(event.submitter || event.target, event.target))) el = event.target;
         if (!el || defaultEvent(el) !== name) return;
         event.preventDefault();
         schedule(el, name, event.submitter || el);