Frontend first draft

frontend/pweb/lib/pages/signup/form/email.dart

@@ -0,0 +1,32 @@
+
+import 'package:flutter/material.dart';
+
+import 'package:pweb/generated/i18n/app_localizations.dart';
+
+//TODO check with /widgets/username.dart
+
+class EmailField extends StatelessWidget {
+  final TextEditingController controller;
+
+  const EmailField({super.key, required this.controller});
+
+  static final _emailRegex = RegExp(r'^[\w-\.]+@([\w-]+\.)+[\w-]{2,4}$');
+
+  @override
+  Widget build(BuildContext context) {
+    return TextFormField(
+      controller: controller,
+      keyboardType: TextInputType.emailAddress,
+      decoration: InputDecoration(
+        labelText: AppLocalizations.of(context)!.username,
+        hintText: AppLocalizations.of(context)!.usernameHint,
+      ),
+      validator: (value) {
+        if (value == null || !_emailRegex.hasMatch(value)) {
+          return AppLocalizations.of(context)!.usernameErrorInvalid;
+        }
+        return null;
+      },
+    );
+  }
+}