AllTooValidator

Validator using the Chain of Responsibility pattern. This is a Kotlin validator that uses the Chain of Responsibility pattern to add validations for inputs or other values.

How to Use

• Basic Validator

  This library includes basic validators like:

  Name	Description
  MinLengthValidator	Checks the minimum length of a string
  MaxLengthValidator	Checks the maximum length of a string
  EqualsLengthValidator	Checks if the length of a string is equal to a value
  EmptyValidator	A shortcut to check if a string is empty
  MinValueValidator	Use this validation for minimum value; this type should be comparable (e.g., int, double, etc.)

  Usage:

  //***** Using Validator Only ******
  // Validate identification number (8 characters)
  val identificationNumber = binding.identificationDocumentET.text?.toString() ?: ""
  val identificationNumberValidator = EqualsLengthValidator(expectedLength = 8, errorMessageResId = R.string.error_invalid_identification_number)
  val identificationNumberResult = identificationNumberValidator.validate(identificationNumber)

• String Builder Validator

  The StringValidatorBuilder helps to add multiple validations at the same time. It stops when one validation fails, so the order is important:

  //***** Using StringValidatorBuilder ******
  // Phone (9-11 characters)
  val phone = binding.phoneET.text?.toString() ?: ""
  // Using a builder
  val phoneValidator = StringValidatorBuilder()
          .addValidator(EmptyValidator(errorMessageResId = R.string.error_empty_phone))
          .addValidator(MinLengthValidator(minLength = 9, errorMessageResId = R.string.error_invalid_phone_number))
          .addValidator(MaxLengthValidator(maxLength = 11, errorMessageResId = R.string.error_invalid_phone_number))
          .build()
  val phoneResult = phoneValidator.validate(phone)

• Custom Validator

  For this, we use AdultAgeValidator. To create a custom validator, it should extend from AllTooValidator and specify the input and output types. In this case, we use a string as input and return an integer value.

  class AdultAgeValidator: AllTooValidator<String, Int> {
      override fun validate(data: String): AllTooValidatorResult<Int> {
          val emptyValidator = EmptyValidator(R.string.error_empty_age)
          val emptyValidationResult = emptyValidator.validate(data)
  
          if (emptyValidationResult is AllTooValidatorResult.Failure) {
              return emptyValidationResult
          }
  
          data.toIntOrNull()?.let { age ->
              val minValueValidator = MinValueValidator(18, R.string.error_age_must_be_adult)
              return minValueValidator.validate(age)
          } ?: run {
              return AllTooValidatorResult.Failure(R.string.error_invalid_age)
          }
      }
  }

Check validation

To check if the validation fails, we show check using the AllTooValidatorResult, in case of success we can we the value, and for failure, we get the errorMessageResId:

sealed class AllTooValidatorResult<out T> {
    data class Success<out T>(val result: T) : AllTooValidatorResult<T>()
    //data class Failure(@StringRes val errorMessageResId: Int) : AllTooValidatorResult<Nothing>()
    data class Failure(val errorMessageResId: Int) : AllTooValidatorResult<Nothing>()
}

And for checking we could do this:

val ageResult = ageValidator.validate(age)

when (ageResult) {
    is AllTooValidatorResult.Failure -> {
        binding.yearsOldTIL.error = getString(ageResult.errorMessageResId)
    }
    is AllTooValidatorResult.Success -> {
        //getting value as Int
        //val ageValue = ageResult.result
        binding.yearsOldTIL.error = null
    }
}

Dependency

• Add the dependencies to your gradle files:

Step 1. Add it in your root build.gradle at the end of repositories

   allprojects {
       repositories {
        ...
        maven { url 'https://jitpack.io' }
        }
    }

Step 2. Add the dependency

    dependencies {
        implementation 'com.github.nowjordanhappy:AllTooValidator:0.1.1'
     }

Extras

• If you want to create your custom builder, use CompositeValidator
• Use AllTooValidator for create your own validator. You need to specify the enter and ouput type, they can be different.

License

MIT License

Copyright (c) 2023 Jordan R. A.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
SOFTWARE.