init

user/plugins/admin/themes/grav/app/pages/page/multilang.js

@@ -0,0 +1,22 @@
+import $ from 'jquery';
+
+$('[name="task"][value="saveas"], [name="task"][value="switchlanguage"]').on('mousedown touchstart', (event) => {
+    let fields = ['lang', 'redirect'];
+    let element = $(event.currentTarget);
+    let form = $(`#${element.attr('form')}`);
+
+    if (!form.length) { return; }
+    fields.forEach((field) => {
+        let value = element.attr(field);
+        if (!value) { return; }
+        let input = form.find(`[name="data[${field}]"]`);
+        if (!input.length) {
+            input = $(`<input type="hidden" name="data[${field}]" value="" />`);
+            form.append(input);
+        }
+
+        input.val(value);
+    });
+
+    return true;
+});