Adding and deleting articles in our database

app/build.gradle

@@ -39,6 +39,7 @@ dependencies {
     implementation 'androidx.appcompat:appcompat:1.1.0'
     implementation 'androidx.core:core-ktx:1.2.0'
     implementation 'androidx.constraintlayout:constraintlayout:1.1.3'
+    implementation 'androidx.legacy:legacy-support-v4:1.0.0'
     testImplementation 'junit:junit:4.12'
     androidTestImplementation 'androidx.test.ext:junit:1.1.1'
     androidTestImplementation 'androidx.test.espresso:espresso-core:3.2.0'

app/src/main/AndroidManifest.xml

@@ -2,14 +2,16 @@
 <manifest xmlns:android="http://schemas.android.com/apk/res/android"
     package="com.androiddevs.mvvmnewsapp">
 
+    <uses-permission android:name="android.permission.INTERNET" />
+
     <application
         android:allowBackup="true"
         android:icon="@mipmap/ic_launcher"
         android:label="@string/app_name"
         android:roundIcon="@mipmap/ic_launcher_round"
         android:supportsRtl="true"
         android:theme="@style/AppTheme">
-        <activity android:name=".MainActivity">
+        <activity android:name=".ui.NewsActivity">
             <intent-filter>
                 <action android:name="android.intent.action.MAIN" />
 

app/src/main/java/com/androiddevs/mvvmnewsapp/adapters/NewsAdapter.kt

@@ -0,0 +1,77 @@
+package com.androiddevs.mvvmnewsapp.adapters
+
+import android.view.LayoutInflater
+import android.view.View
+import android.view.ViewGroup
+import androidx.recyclerview.widget.AsyncListDiffer
+import androidx.recyclerview.widget.DiffUtil
+import androidx.recyclerview.widget.RecyclerView
+import com.androiddevs.mvvmnewsapp.R
+import com.androiddevs.mvvmnewsapp.models.Article
+import com.bumptech.glide.Glide
+import kotlinx.android.synthetic.main.item_article_preview.view.*
+
+class NewsAdapter : RecyclerView.Adapter<NewsAdapter.ArticleViewHolder>() {
+
+    inner class ArticleViewHolder(itemView: View): RecyclerView.ViewHolder(itemView)
+
+    private val differCallback = object : DiffUtil.ItemCallback<Article>() {
+        override fun areItemsTheSame(oldItem: Article, newItem: Article): Boolean {
+            return oldItem.url == newItem.url
+        }
+
+        override fun areContentsTheSame(oldItem: Article, newItem: Article): Boolean {
+            return oldItem == newItem
+        }
+    }
+
+    val differ = AsyncListDiffer(this, differCallback)
+
+    override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): ArticleViewHolder {
+        return ArticleViewHolder(
+            LayoutInflater.from(parent.context).inflate(
+                R.layout.item_article_preview,
+                parent,
+                false
+            )
+        )
+    }
+
+    override fun getItemCount(): Int {
+        return differ.currentList.size
+    }
+
+    private var onItemClickListener: ((Article) -> Unit)? = null
+
+    override fun onBindViewHolder(holder: ArticleViewHolder, position: Int) {
+        val article = differ.currentList[position]
+        holder.itemView.apply {
+            Glide.with(this).load(article.urlToImage).into(ivArticleImage)
+            tvSource.text = article.source.name
+            tvTitle.text = article.title
+            tvDescription.text = article.description
+            tvPublishedAt.text = article.publishedAt
+
+            setOnClickListener {
+                onItemClickListener?.let { it(article) }
+            }
+        }
+    }
+
+    fun setOnItemClickListener(listener: (Article) -> Unit) {
+        onItemClickListener = listener
+    }
+}
+
+
+
+
+
+
+
+
+
+
+
+
+

app/src/main/java/com/androiddevs/mvvmnewsapp/api/NewsAPI.kt

@@ -0,0 +1,30 @@
+package com.androiddevs.mvvmnewsapp.api
+
+import com.androiddevs.mvvmnewsapp.models.NewsResponse
+import com.androiddevs.mvvmnewsapp.util.Constants.Companion.API_KEY
+import retrofit2.Response
+import retrofit2.http.GET
+import retrofit2.http.Query
+
+interface NewsAPI {
+
+    @GET("v2/top-headlines")
+    suspend fun getBreakingNews(
+        @Query("country")
+        countryCode: String = "us",
+        @Query("page")
+        pageNumber: Int = 1,
+        @Query("apiKey")
+        apiKey: String = API_KEY
+    ): Response<NewsResponse>
+
+    @GET("v2/everything")
+    suspend fun searchForNews(
+        @Query("q")
+        searchQuery: String,
+        @Query("page")
+        pageNumber: Int = 1,
+        @Query("apiKey")
+        apiKey: String = API_KEY
+    ): Response<NewsResponse>
+}

app/src/main/java/com/androiddevs/mvvmnewsapp/api/RetrofitInstance.kt

@@ -0,0 +1,29 @@
+package com.androiddevs.mvvmnewsapp.api
+
+import com.androiddevs.mvvmnewsapp.util.Constants.Companion.BASE_URL
+import okhttp3.OkHttpClient
+import okhttp3.logging.HttpLoggingInterceptor
+import retrofit2.Retrofit
+import retrofit2.converter.gson.GsonConverterFactory
+
+class RetrofitInstance {
+    companion object {
+
+        private val retrofit by lazy {
+            val logging = HttpLoggingInterceptor()
+            logging.setLevel(HttpLoggingInterceptor.Level.BODY)
+            val client = OkHttpClient.Builder()
+                .addInterceptor(logging)
+                .build()
+            Retrofit.Builder()
+                .baseUrl(BASE_URL)
+                .addConverterFactory(GsonConverterFactory.create())
+                .client(client)
+                .build()
+        }
+
+        val api by lazy {
+            retrofit.create(NewsAPI::class.java)
+        }
+    }
+}

app/src/main/java/com/androiddevs/mvvmnewsapp/db/ArticleDao.kt

@@ -0,0 +1,18 @@
+package com.androiddevs.mvvmnewsapp.db
+
+import androidx.lifecycle.LiveData
+import androidx.room.*
+import com.androiddevs.mvvmnewsapp.models.Article
+
+@Dao
+interface ArticleDao {
+
+    @Insert(onConflict = OnConflictStrategy.REPLACE)
+    suspend fun upsert(article: Article): Long
+
+    @Query("SELECT * FROM articles")
+    fun getAllArticles(): LiveData<List<Article>>
+
+    @Delete
+    suspend fun deleteArticle(article: Article)
+}

app/src/main/java/com/androiddevs/mvvmnewsapp/db/ArticleDatabase.kt

@@ -0,0 +1,35 @@
+package com.androiddevs.mvvmnewsapp.db
+
+import android.content.Context
+import androidx.room.Database
+import androidx.room.Room
+import androidx.room.RoomDatabase
+import androidx.room.TypeConverters
+import com.androiddevs.mvvmnewsapp.models.Article
+
+@Database(
+    entities = [Article::class],
+    version = 1
+)
+@TypeConverters(Converters::class)
+abstract class ArticleDatabase : RoomDatabase() {
+
+    abstract fun getArticleDao(): ArticleDao
+
+    companion object {
+        @Volatile
+        private var instance: ArticleDatabase? = null
+        private val LOCK = Any()
+
+        operator fun invoke(context: Context) = instance ?: synchronized(LOCK) {
+            instance ?: createDatabase(context).also { instance = it }
+        }
+
+        private fun createDatabase(context: Context) =
+            Room.databaseBuilder(
+                context.applicationContext,
+                ArticleDatabase::class.java,
+                "article_db.db"
+            ).build()
+    }
+}

app/src/main/java/com/androiddevs/mvvmnewsapp/db/Converters.kt

@@ -0,0 +1,17 @@
+package com.androiddevs.mvvmnewsapp.db
+
+import androidx.room.TypeConverter
+import com.androiddevs.mvvmnewsapp.models.Source
+
+class Converters {
+
+    @TypeConverter
+    fun fromSource(source: Source): String {
+        return source.name
+    }
+
+    @TypeConverter
+    fun toSource(name: String): Source {
+        return Source(name, name)
+    }
+}

app/src/main/java/com/androiddevs/mvvmnewsapp/models/Article.kt

@@ -0,0 +1,22 @@
+package com.androiddevs.mvvmnewsapp.models
+
+
+import androidx.room.Entity
+import androidx.room.PrimaryKey
+import java.io.Serializable
+
+@Entity(
+    tableName = "articles"
+)
+data class Article(
+    @PrimaryKey(autoGenerate = true)
+    var id: Int? = null,
+    val author: String,
+    val content: String,
+    val description: String,
+    val publishedAt: String,
+    val source: Source,
+    val title: String,
+    val url: String,
+    val urlToImage: String
+) : Serializable

app/src/main/java/com/androiddevs/mvvmnewsapp/models/NewsResponse.kt

@@ -0,0 +1,10 @@
+package com.androiddevs.mvvmnewsapp.models
+
+
+import com.androiddevs.mvvmnewsapp.models.Article
+
+data class NewsResponse(
+    val articles: List<Article>,
+    val status: String,
+    val totalResults: Int
+)

app/src/main/java/com/androiddevs/mvvmnewsapp/models/Source.kt

@@ -0,0 +1,9 @@
+package com.androiddevs.mvvmnewsapp.models
+
+
+import com.google.gson.annotations.SerializedName
+
+data class Source(
+    val id: Any,
+    val name: String
+)

app/src/main/java/com/androiddevs/mvvmnewsapp/repository/NewsRepository.kt

@@ -0,0 +1,21 @@
+package com.androiddevs.mvvmnewsapp.repository
+
+import com.androiddevs.mvvmnewsapp.api.RetrofitInstance
+import com.androiddevs.mvvmnewsapp.db.ArticleDatabase
+import com.androiddevs.mvvmnewsapp.models.Article
+
+class NewsRepository(
+    val db: ArticleDatabase
+) {
+    suspend fun getBreakingNews(countryCode: String, pageNumber: Int) =
+        RetrofitInstance.api.getBreakingNews(countryCode, pageNumber)
+
+    suspend fun searchNews(searchQuery: String, pageNumber: Int) =
+        RetrofitInstance.api.searchForNews(searchQuery, pageNumber)
+
+    suspend fun upsert(article: Article) = db.getArticleDao().upsert(article)
+
+    fun getSavedNews() = db.getArticleDao().getAllArticles()
+
+    suspend fun deleteArticle(article: Article) = db.getArticleDao().deleteArticle(article)
+}

app/src/main/java/com/androiddevs/mvvmnewsapp/ui/NewsActivity.kt

@@ -0,0 +1,26 @@
+package com.androiddevs.mvvmnewsapp.ui
+
+import androidx.appcompat.app.AppCompatActivity
+import android.os.Bundle
+import androidx.lifecycle.ViewModelProvider
+import androidx.navigation.fragment.findNavController
+import androidx.navigation.ui.setupWithNavController
+import com.androiddevs.mvvmnewsapp.R
+import com.androiddevs.mvvmnewsapp.db.ArticleDatabase
+import com.androiddevs.mvvmnewsapp.repository.NewsRepository
+import kotlinx.android.synthetic.main.activity_news.*
+
+class NewsActivity : AppCompatActivity() {
+
+    lateinit var viewModel: NewsViewModel
+
+    override fun onCreate(savedInstanceState: Bundle?) {
+        super.onCreate(savedInstanceState)
+        setContentView(R.layout.activity_news)
+
+        val newsRepository = NewsRepository(ArticleDatabase(this))
+        val viewModelProviderFactory = NewsViewModelProviderFactory(newsRepository)
+        viewModel = ViewModelProvider(this, viewModelProviderFactory).get(NewsViewModel::class.java)
+        bottomNavigationView.setupWithNavController(newsNavHostFragment.findNavController())
+    }
+}