authentication - 如何在Flutter中使用流转换器根据另一个输入字段的值验证输入

Question

我有一个包含电子邮件，密码和确认密码字段的注册表格。我要实现的是正确验证输入。现在，我正在使用一个简单的算法来验证电子邮件和密码，这很好。对于确认密码字段，我希望它与有效密码的条件匹配，并且的值应与密码的值匹配。我要使用流转换还是完全不同的方法？

AUTHENTICATION BLOC

  final _emailTFController = TextEditingController();
  final _passwordTFController = TextEditingController();
  final _confirmPasswordTFController = TextEditingController();

  Stream<String> get emailStream =>
      _emailController.stream.transform(Validators.validateEmail);

  Stream<String> get passwordStream =>
      _passwordController.stream.transform(Validators.validatePassword);

VALIDATORS

import 'dart:async';

class Validators {
  static final validateEmail =
      StreamTransformer<String, String>.fromHandlers(handleData: (email, sink) {
    if (email.contains('@')) {
      sink.add(email);
    } else {
      sink.addError('Enter a valid email');
    }
  });

  static final validatePassword = StreamTransformer<String, String>.fromHandlers(
      handleData: (password, sink) {
    if (password.length > 4) {
      sink.add(password);
    } else {
      sink.addError('Invalid passord, please enter more than 4 characters.');
    }
  });
}

Answer 1

使用BehaviourSubject代替Stream Controller

final passwordController=BehaviorSubject<String>();

并使用带有doOnData方法的ConfirmPassword函数，如下所示

Stream<String> get confirmpassword =>
      confirmpasswordController.stream.transform(confirmPasswordValidator)
          .doOnData((String c){
        // If the password is accepted (after validation of the rules)
        // we need to ensure both password and retyped password match
        if (0 != passwordController.value.compareTo(c)){
          // If they do not match, add an error
          confirmpasswordController.addError("Confirm Password donot match");
        }
      });