mahdit83

class ConsumableLiveData<T>(var consume: Boolean = false) : MutableLiveData<T>() {

    private val pending = AtomicBoolean(false)

    override fun observe(owner: LifecycleOwner, observer: Observer<in T>) {
        super.observe(owner, Observer<T> {
            if(consume){
                if(pending.compareAndSet(true,false)) observer.onChanged(it)
            }else{
                observer.onChanged(it)

mahdit83

fun <A, B> DoubleTriggerLiveData(a: LiveData<A>, b: LiveData<B>): LiveData<Pair<A, B>> {
    return MediatorLiveData<Pair<A, B>>().apply {
        var lastA: A? = null
        var lastB: B? = null

        fun update() {
            val localLastA = lastA
            val localLastB = lastB
            if (localLastA != null && localLastB != null)
                this.value = Pair(localLastA, localLastB)

mahdit83

class FieldValidator<T>(private var fieldObject: T) {

    // Store the validation rules at a ValidationRule List, by fieldId
    private val rules = ArrayList<Rule<T>>()

    // Store the field error string, or null if validation pass
    private val validations = MutableLiveData<String>()

    // Get the LiveData<String> for the property
    fun getValidation(): LiveData<String>? {