first commit

media/plg_installer_folderinstaller/js/folderinstaller.js

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+/**
+ * @copyright   (C) 2020 Open Source Matters, Inc. <https://www.joomla.org>
+ * @license     GNU General Public License version 2 or later; see LICENSE.txt
+ */
+
+Joomla = window.Joomla || {};
+(Joomla => {
+
+  document.addEventListener('DOMContentLoaded', () => {
+    Joomla.submitbuttonfolder = () => {
+      const form = document.getElementById('adminForm');
+
+      // do field validation
+      if (form.install_directory.value === '') {
+        Joomla.renderMessages({
+          warning: [Joomla.Text._('PLG_INSTALLER_FOLDERINSTALLER_NO_INSTALL_PATH')]
+        });
+      } else {
+        const loading = document.getElementById('loading');
+        if (loading) {
+          loading.classList.remove('hidden');
+        }
+        form.installtype.value = 'folder';
+        form.submit();
+      }
+    };
+  });
+})(Joomla);

media/plg_installer_folderinstaller/js/folderinstaller.min.js

@@ -0,0 +1 @@
+Joomla=window.Joomla||{},(e=>{document.addEventListener("DOMContentLoaded",(()=>{e.submitbuttonfolder=()=>{const t=document.getElementById("adminForm");if(""===t.install_directory.value)e.renderMessages({warning:[e.Text._("PLG_INSTALLER_FOLDERINSTALLER_NO_INSTALL_PATH")]});else{const e=document.getElementById("loading");e&&e.classList.remove("hidden"),t.installtype.value="folder",t.submit()}}}))})(Joomla);