Stream Fluent Validation

Stream Fluent Validation is a validation library for Flutter developer . It supports text validation for String, EditText, TextView, AutoCompleteTextView, TextInputLayout, and Spinner. It comes with lots of built-in rules for validation such as email, special character validations and so on.

Quick Stream Fluent Validation

For example, you can validate any Form like this:

  final LoginValidation loginValidation = LoginValidation();

class LoginValidation extends AbstractValidator<LoginValidation> {
  StreamValidator<String> email = StreamValidator<String>();
  StreamValidator<String> password = StreamValidator<String>();

  LoginValidation() {
    ruleFor((e) => (e as LoginValidation).email)
        .isNotEmpty()
        .withMessage("email should not be empty")
        .emailAddress()
        .withMessage("email should be valid !!.");

    ruleFor((e) => (e as LoginValidation).password).between(3, 4)  .withMessage("password  should contain from 3 to 4 digit  !!.");
  }
}

// Later on
StreamBuilder(
        stream:loginValidation.email.stream,
        builder: (context, snap) {
          return TextField(
            keyboardType: TextInputType.emailAddress,
            onChanged: loginValidation.email.valueChange,
            decoration: InputDecoration(
                labelText: "Email address",
                hintText: "you@example.com",
                errorText: snap.hasError ? "${snap.error}" : null),
          );
        },
      )
      
      StreamBuilder(
        stream: loginValidation.password.stream,
        builder: (context, snap) {
          return TextField(
            keyboardType: TextInputType.number,
            onChanged:loginValidation.password.valueChange,
            obscureText: true,
            decoration: InputDecoration(
                labelText: "Password",
                hintText: "******",
                errorText: snap.hasError ? "${snap.error}" : null),
          );
        },
      );

Multiple Validation Checks wiht message

Stream Fluent Validation also supports multiple validation checks like this:

class LoginValidation extends AbstractValidator<LoginValidation> {
  StreamValidator<String> email = StreamValidator<String>();

  LoginValidation() {
    ruleFor((e) => (e as LoginValidation).email)
        .isNotEmpty()
        .withMessage("email should not be empty")
        .emailAddress()
        .withMessage("email should be valid !!.");

  }
}

Create Your Own Custom Validation Checks

You can also add your own custom by extending use must validator rule.

   ruleFor((e) => (e as LoginValidation).userName).must((Object value) {
      return value.toString().isNotEmpty &&
          value.toString().contains(".") &&
          value.toString().length >= 3;
    }).withMessage("user name is not correct");

Built in Validators

• notEmpty - (checks the object is a String and not empty)
• empty - (checks the object is a String and is empty)
• notEqual - (checks if an current stream is not equal to another)
• equal - (checks if an current stream is equal to another)
• notEqualToConstValue - (checks if an value is not equal to another)
• equalToConstValue - (checks if an value is equal to another)
• length - (checks the object is a String and is between two other numbers)

Extra Built In Validators

These are not included in the default C# version.

• isValidEmailAddress - (checks the object is a String and is a valid email address)

Contributing

Feel free to do a pull request with any ideas and I will check each one. ¬ Rad