psteiger

// Location-related Kotlin extension properties for Android.
// They must be implemented in an Activity because Geocoder needs a context.
// Or else, they must be turned from extension properties to extension functions that receive a context as parameter.


// Example of use
// Use case: show the user his locality name on a TextView
val userLocation = Location(someLatitude, someLongitude)
launch(UI) {
    aTextView.text = userLocation.localityName.await()

psteiger

// Usage:                    logTime { anyFunction() }
// Output in Android logcat: LogTime: 2ms

// logTime returns the value and type returned by the function, so you can:
//
// val distance: Int = logTime { distanceTo.localized }
//
// It will print to console log the time `distanceTo.localized` took to process,
// and will return its value to be captured by `distance` var.

psteiger

// how to check if a string contains a number of chars?  

// the java-esque way:

imageNameWithoutExtension.contains('.') || 
    imageNameWithoutExtension.contains('#') || 
    imageNameWithoutExtension.contains('$') ||
    imageNameWithoutExtension.contains('[') || 
    imageNameWithoutExtension.contains(']')

psteiger

usersLiveData.observe(viewLifecycleOwner, Observer { resource ->
    resource.onSuccess { userList: HashMap<String, User> ->
        usersLoaded(user) 
    }.onLoading { partialUserList: HashMap<String, User>? ->
        usersAreLoading(partialUserList)
    }.onFailure { cause: Throwable? ->
        userLoadFailed(cause)
    }
})

psteiger

data class User(
    var name: String? = null,
    var email: String? = null,    
    var team: String? = null
)

psteiger

sealed class Resource<out T> {
    data class Success<out T>(val data: T) : Resource<T>()
    data class Loading<out T>(val partialData: T? = null) : Resource<T>()
    data class Failure<out T>(val throwable: Throwable? = null) : Resource<T>()
}

psteiger

sealed class Resource<out T> {
    
    data class Success<out T>(val data: T) : Resource<T>()
    data class Loading<out T>(val partialData: T? = null) : Resource<T>()
    data class Failure<out T>(val throwable: Throwable? = null) : Resource<T>()

    val extractData: T? get() = when (this) {
        is Success -> data
        is Loading -> partialData
        is Failure -> null

psteiger

open class FirebaseResourceLiveData : LiveData<Resource<DataSnapshot>> {
    
    init {
        value = Resource.Loading()
    }
    
    constructor(path: String) {
        query = FirebaseDatabase.getInstance().getReference(path)
    }

psteiger

class UsersSnapLiveData : FirebaseResourceLiveData("users")

psteiger

inline fun <X, Y> LiveData<Resource<X>>.mapLiveDataResource(
    crossinline transform: (X) -> Y
): LiveData<Resource<Y>> = 
    map { it.mapResource(transform) } 
    
// map from androidx.lifecycle:lifecycle-livedata-ktx
// Equivalent to Transformations.map(source, func)