No submit if no photo is selected

app/assets/javascripts/archive-uploader.js

@@ -1,15 +1,30 @@
-const profileFileBtn = document.getElementById("profile-file-btn");
+const profileFileButton = document.getElementById("profile-file-btn");
 
 const profileFileChosen = document.getElementById("profile-file-chosen");
 
-profileFileBtn.addEventListener("change", function() {
+profileFileButton.addEventListener("change", function() {
   profileFileChosen.textContent = this.files[0].name;
+  checkProfileUploadButton();
 });
 
-const photosFileBtn = document.getElementById("photos-file-btn");
+const photosFileButton = document.getElementById("photos-file-btn");
 
 const photosFileChosen = document.getElementById("photos-file-chosen");
 
-photosFileBtn.addEventListener("change", function() {
+photosFileButton.addEventListener("change", function() {
   photosFileChosen.textContent = this.files[0].name;
+  checkProfileUploadButton();
 });
+
+const checkProfileUploadButton = function() {
+  let photo_files = $("#profile-file-btn")[0].files;
+  let profile_files = $("#photos-file-btn")[0].files;
+
+  if ((photo_files.size + profile_files.size) === 0)
+  {
+    $("#upload_profile_files").attr('disabled', 'disabled');
+  } else {
+    $("#upload_profile_files").removeAttr('disabled');
+  }
+
+}

app/views/users/_import_account_modal.haml

@@ -57,6 +57,9 @@
               .clearfix
                 .btn.btn-default{data: {dismiss: "modal"}}
                   = t("users.import_modal.cancel")
-                = f.submit t("users.import_modal.start_import"), class: "btn btn-primary.pull-right", id: "change_email_preferences"
+                = f.submit t("users.import_modal.start_import"),
+                class: "btn btn-primary.pull-right",
+                id: "upload_profile_files",
+                disabled: true
 
 = javascript_include_tag "archive-uploader"