RxValidator2

The simplest way to add reactive validation to your app

How it works

Problem

In your application, there are fields that must be validated. When the number of validation rules becomes greater than 1, to control the display of errors in the fields becomes difficult.

Solve

Separate your validation logic by S in SOLID, into own classes. After that, attach validaton rules to your fields and combine validation results for change some ui states (ex. change visibility of button)

Usage

View layer

Firstly, you need write your own rules validation for some fields.

class NotNullRule : ValidateRule {
    override fun errorMessage() = "Text must not be null"
    
    override fun validate(data: String?): Boolean {
        return data != null // your validation logic
    }
}

Attach your validation rules to field

val loginObservable: Observable<Boolean> = RxValidator(editLogin)
        .apply {
            add(NotEmptyRule())
            add(MinLengthRule(5))
        }.asObservable()
        
val emailObservable: Observable<Boolean> = RxValidator(editEmail)
        .apply {
            add(NotEmptyRule())
            add(MinLengthRule(7))
        }.asObservable()

Combine your validation results to change button state

RxCombineValidator(loginObservable, emailObservable)
        .asObservable()
        .distinctUntilChanged()
        .subscribe({ valid ->
            button.isEnabled = valid
        })

Model layer

Create text watcher for your field

RxValidator.createObservable(editEmail)
        .subscribe({
            mainPresenter.onEmailTextChanges(it)
        })

Add some validation and handle events without rx

val validator = Validator().apply {
    add(NotNullRule())
    add(NotEmptyRule())
}
    
fun onEmailTextChanges(text: String) {
    validator.validate(text,
            onSuccess = {
                view?.onEmailValid()
            },
            onError = { errorMessage ->
                view?.onEmailInvalid(errorMessage)
            })
}

Why

• You can use it in model layer, for consistent architecture rules
• You can use it in view layer, with rx wrappers
• You need test only your custom validation rules, because the main features of the library are already covered by tests
• Class Validator extends from LinkedHashSet, that you can use all benefits of this collection implementation

Install

Be sure, that you have Jitpack in your root gradle file

allprojects {
    repositories {
      jcenter()
+     maven { url "https://jitpack.io" }
    }
}

Include dependency with RxValidator in your app.gradle file with:

+ compile 'com.github.whalemare:RxValidator2:1.3'

License

Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at

   http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.