Working but incomplete

static/js/utils/massInput.js

@@ -30,6 +30,8 @@
     var massInputFormSubmitHandler;
     var massInputForm;
 
+    var massInputEnctype;
+
     function init() {
       if (!element) {
         throw new Error('Mass Input utility cannot be setup without an element!');
@@ -62,7 +64,7 @@
 
       var method = massInputForm.getAttribute('method') || 'POST';
       var url = massInputForm.getAttribute('action') || window.location.href;
-      var enctype = massInputForm.getAttribute('enctype') || 'application/json';
+      massInputEnctype = massInputForm.getAttribute('enctype') || 'application/json';
 
       var requestFn;
       if (HttpClient[method.toLowerCase()]) {
@@ -84,7 +86,7 @@
           requestFn(
             url,
             {
-              'Content-Type': enctype,
+              'Content-Type': massInputEnctype,
               'Mass-Input-Shortcircuit': massInputId,
             },
             requestBody,
@@ -109,15 +111,23 @@
 
     function serializeForm() {
       var formData = new FormData(massInputForm);
-      var formBody = [];
 
-      for(var formField of formData) {
+      Array.from(element.querySelectorAll('button:focus, button:active')).forEach(function (el) {
-        var encodedKey = encodeURIComponent(formField[0]);
+        if (!el.name || !el.value)
-        var encodedValue = encodeURIComponent(formField[1]);
+          return;
-        formBody.push(encodedKey + "=" + encodedValue);
+
+        console.log(el);
+
+        formData.append(el.name, el.value);
+      });
+
+      if (massInputEnctype === 'application/x-www-form-urlencoded') {
+        return new URLSearchParams(formData);
+      } else if (massInputEnctype === 'multipart/form-data') {
+        return formData;
+      } else {
+        throw new Error('Unsupported form enctype: ' + massInputEnctype);
       }
-
-      return formBody.join("&");
     }
 
     function reset() {