Design pattern to create validators. By wrapping TextInputs with Validators, we bind validation checks to events required, only customizing error messages and validation required.

• Material TextInputLayout support.
• OnFocusChange and onTextChanged events.
• Error messages customizable.
• Error handling callback.
• Provided Email Validator.
• Provided Phone Number Validator.
• Provided Password Validator (confirmation, upper, lower, digit, special, minimum characters).

• Android SDK 8.0+

allprojects {
 repositories {
    jcenter()
    maven { url "https://jitpack.io" }
 }
}
dependencies {
    compile 'com.github.philip-bui:input-validator:1.0.0'
}

  EditText email = (EditText) findViewById(R.id.email);
  EmailValidator emailValidator = new EmailValidator(email);
  emailValidator.setTextInputLayoutValidate(true);
  emailValidator.setRequired(true, "Required email address"); // Error message on empty.
  emailValidator.setLoseFocusValidate(true); // onFocusChange event validation binded.
  if (emailValidator.validate()) {
    ... // Successful validation.
  } else {
    ... // Unsucessful validation. Error messages / callbacks have been displayed.
  }

Customization is easy. To create new Validation logic, just extend Validator.

public class PhoneNumberValidator extends Validator {
    public PhoneNumberValidator(EditText editText) {
        super(editText);
    }

    @Override
    public String onValidate(String string, Context context) {
        if (!Patterns.PHONE.matcher(string).matches()) {
            return context.getString(R.string.av_phone_number_is_invalid);
        }
        return null;
    }
}

Alternatively multiple Validators can be composed onto one (see ConfirmPasswordValidator), representing a checklist.

validateListener Default: null

Interface when a success or error validation happens.

stopTypingValidate Default: false

Whether to validate when the user stops typing.

loseFocusValidate Default: true

Whether to validate when the user changes focus FROM the field.

showError Default: true

Whether to show error messages. Useful to set false if you want to manually handle error messages.

textInputValidate Default: false

Whether to show the error message on the parent TextInputLayout. If the parent of the EditText is not a TextInputLayout, it throws an Exception when set to true.

required Default: false, "Required field"

Whether to return an error when empty. This is called before validate(), and also comes with a custom Error message.

Input Validator is available under the MIT license. See LICENSE for details.