alwarren

/**
 * An MVP integration test
 *
 * This test verifies integration of all three MVP components without actually implementing
 * any of those components in the application.
 *
 * Passing on 9/24/2018
 */
class MainPresenterTest {
    private val repository: Repository = mock(Repository::class.java)

alwarren

interface Greeting {
    fun getData(): String
}

class GreetingRepository
    @Inject
    constructor(
            @Named(HELLO) private val hello: Greeting,
            @Named(GOODBYE) private val goodbye: Greeting
    ) {

alwarren

A Step-by-step Process for Adding Dagger2 to Android

Dagger2 is a powerful dependency injection library. However, it can be confusing for the first-time user. And unless things are created in the correct order, builds fail with cryptic error messages.

These step-by-step instructions were created while setting up a new project to document the process.

Project Setup

1. Setup Gradle version variables (optional)
2. Setup Gradle dependencies

3. Create an App class that extends Application

alwarren

sealed class ApiResponse {
    class Loading(val loading: Boolean = true) : ApiResponse()
    class Success<T>(val data: T) : ApiResponse()
    class Error(val message: String) : ApiResponse()

    // For demonstration purposes only
    companion object {
        fun evaluate(response: ApiResponse) {
            when(response) {
                is ApiResponse.Loading -> {

alwarren

import android.os.Bundle
import android.support.v7.app.AppCompatActivity
import android.view.Menu
import android.view.MenuItem
import kotlinx.android.synthetic.main.activity_main.*
import android.app.AlarmManager
import android.app.Notification
import android.os.SystemClock
import android.app.PendingIntent
import android.content.Context

alwarren

class RecyclerAdapter(private val users: ArrayList<User>) : RecyclerView.Adapter<RecyclerAdapter.UserHolder>() {
    override fun getItemCount(): Int {
        return users.size
    }

    override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): RecyclerAdapter.UserHolder {
        // see Extensions.kt
        val inflatedView = parent.inflate(R.layout.list_row, false)
        return UserHolder(inflatedView)
    }

alwarren

package com.example.domain.api

import retrofit2.Call
import retrofit2.Callback
import retrofit2.Response
import retrofit2.Retrofit
import retrofit2.converter.gson.GsonConverterFactory

open class RetrofitRepo<out S>(clazz: Class<S>) {
    val service: S = Api.service(clazz)

alwarren

class SwitchMapViewModel @Inject constructor(private val dataSource: Data) : ViewModel() {

    // observed by ViewModel as a trigger to retrieve data from the source
    private var liveTrigger: MutableLiveData<String> = MutableLiveData()

    // observed by Activity/Fragment or some other class as a trigger to do something with the data
    private var liveData: LiveData<String>

    init {
        // default observable trigger

alwarren

/**
 * A generic wrapper class for determining the success or failure of some method
 *
 * In the business logic, examine the instance class to determine success or failure
 *
 * Example -
 * <pre>
 *     <code>
 *         val result: ResponseObject = SomeRepository().getData(true)
 *         if (result is ResponseObject.Success) {

alwarren

public class SingletonClass {
    // dummy object for synchronization
    private static final Object sLock = new Object();

    // single instance of the class
    private static SingletonClass INSTANCE;

    public static SingletonClass getInstance() {
        // force threads to wait until synchronized block completes
        synchronized (sLock) {