Form submission caching & url pre-fill confusion (#37)

* Form submission caching & url pre-fill confusion

* formPendingSubmissionKey as common mixins

* Rename mixin formPendingSubmissionKey

Co-authored-by: Julien Nahum <jhumanj@MacBook-Pro-de-Julien.local>

resources/js/mixins/forms/form-pending-submission-key.js

@@ -0,0 +1,22 @@
+const cyrb53 = (str, seed = 0) => {
+  let h1 = 0xdeadbeef ^ seed,
+    h2 = 0x41c6ce57 ^ seed;
+  for (let i = 0, ch; i < str.length; i++) {
+    ch = str.charCodeAt(i);
+    h1 = Math.imul(h1 ^ ch, 2654435761);
+    h2 = Math.imul(h2 ^ ch, 1597334677);
+  }
+
+  h1 = Math.imul(h1 ^ (h1 >>> 16), 2246822507) ^ Math.imul(h2 ^ (h2 >>> 13), 3266489909);
+  h2 = Math.imul(h2 ^ (h2 >>> 16), 2246822507) ^ Math.imul(h1 ^ (h1 >>> 13), 3266489909);
+
+  return 4294967296 * (2097151 & h2) + (h1 >>> 0);
+};
+
+export default {
+  computed: {
+    formPendingSubmissionKey() {
+      return (this.form) ? this.form.form_pending_submission_key + '-' + cyrb53(window.location.href) : ''
+    }
+  }
+}