MVVM arc skeleton

Author: sijan8s3

app/src/main/java/com/sijanneupane/mvvmnews/repository/NewsRepository.kt

@@ -0,0 +1,8 @@
+package com.sijanneupane.mvvmnews.repository
+
+import com.sijanneupane.mvvmnews.db.ArticleDatabase
+
+class NewsRepository(
+    val db: ArticleDatabase //parameter
+) {
+}

app/src/main/java/com/sijanneupane/mvvmnews/ui/MainActivity.kt

@@ -2,17 +2,26 @@ package com.sijanneupane.mvvmnews.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.sijanneupane.mvvmnews.R
+import com.sijanneupane.mvvmnews.db.ArticleDatabase
+import com.sijanneupane.mvvmnews.repository.NewsRepository
 import kotlinx.android.synthetic.main.activity_main.*
 
 class MainActivity : AppCompatActivity() {
+    lateinit var viewModel: NewsViewModel
 
     override fun onCreate(savedInstanceState: Bundle?) {
         super.onCreate(savedInstanceState)
         setContentView(R.layout.activity_main)
 
+        //initializations and assign
+        val repository= NewsRepository(ArticleDatabase(this))
+        val viewModelProviderFactory= NewsViewModelProviderFactory(repository)
+        viewModel= ViewModelProvider(this, viewModelProviderFactory).get(NewsViewModel::class.java)
+
         bottomNavigationView.setupWithNavController(newsNavHostFrag.findNavController())
 
 

app/src/main/java/com/sijanneupane/mvvmnews/ui/NewsViewModel.kt

@@ -0,0 +1,9 @@
+package com.sijanneupane.mvvmnews.ui
+
+import androidx.lifecycle.ViewModel
+import com.sijanneupane.mvvmnews.repository.NewsRepository
+
+class NewsViewModel(
+    val newsRepository: NewsRepository //parameter
+) : ViewModel(){
+}

app/src/main/java/com/sijanneupane/mvvmnews/ui/NewsViewModelProviderFactory.kt

@@ -0,0 +1,16 @@
+package com.sijanneupane.mvvmnews.ui
+
+import androidx.lifecycle.ViewModel
+import androidx.lifecycle.ViewModelProvider
+import com.sijanneupane.mvvmnews.repository.NewsRepository
+/*
+To define how our view model should be created
+ */
+class NewsViewModelProviderFactory(
+    val newsRepository: NewsRepository
+    ) : ViewModelProvider.Factory{
+
+    override fun <T : ViewModel?> create(modelClass: Class<T>): T {
+        return NewsViewModel(newsRepository) as T
+    }
+}

app/src/main/java/com/sijanneupane/mvvmnews/ui/fragments/ArticleFragment.kt

@@ -1,7 +1,18 @@
 package com.sijanneupane.mvvmnews.ui.fragments
 
+import android.os.Bundle
+import android.view.View
 import androidx.fragment.app.Fragment
 import com.sijanneupane.mvvmnews.R
+import com.sijanneupane.mvvmnews.ui.MainActivity
+import com.sijanneupane.mvvmnews.ui.NewsViewModel
 
 class ArticleFragment : Fragment(R.layout.fragment_article){
+    lateinit var viewModel: NewsViewModel
+
+    override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
+        super.onViewCreated(view, savedInstanceState)
+        viewModel= (activity as MainActivity).viewModel
+
+    }
 }

app/src/main/java/com/sijanneupane/mvvmnews/ui/fragments/BreakingNewsFragment.kt

@@ -1,7 +1,21 @@
 package com.sijanneupane.mvvmnews.ui.fragments
 
+import android.os.Bundle
+import android.view.View
 import androidx.fragment.app.Fragment
+import androidx.lifecycle.viewModelScope
 import com.sijanneupane.mvvmnews.R
+import com.sijanneupane.mvvmnews.ui.MainActivity
+import com.sijanneupane.mvvmnews.ui.NewsViewModel
 
 class BreakingNewsFragment : Fragment(R.layout.fragment_breaking_news) {
+    lateinit var viewModel: NewsViewModel
+
+    override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
+        super.onViewCreated(view, savedInstanceState)
+
+        //set viewModels to fragment activity
+        //and we cast that as MainActivity so that we can have access to the view model created at MainActivity
+        viewModel= (activity as MainActivity).viewModel
+    }
 }

app/src/main/java/com/sijanneupane/mvvmnews/ui/fragments/SavedNewsFragment.kt

@@ -1,7 +1,21 @@
 package com.sijanneupane.mvvmnews.ui.fragments
 
+import android.os.Bundle
+import android.view.View
 import androidx.fragment.app.Fragment
 import com.sijanneupane.mvvmnews.R
+import com.sijanneupane.mvvmnews.ui.MainActivity
+import com.sijanneupane.mvvmnews.ui.NewsViewModel
 
 class SavedNewsFragment : Fragment(R.layout.fragment_saved_news) {
+
+    lateinit var viewModel: NewsViewModel
+
+    override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
+        super.onViewCreated(view, savedInstanceState)
+
+        //set viewModels to fragment activity
+        //and we cast that as MainActivity so that we can have access to the view model created at MainActivity
+        viewModel= (activity as MainActivity).viewModel
+    }
 }

app/src/main/java/com/sijanneupane/mvvmnews/ui/fragments/SearchNewsFragment.kt

@@ -1,7 +1,21 @@
 package com.sijanneupane.mvvmnews.ui.fragments
 
+import android.os.Bundle
+import android.view.View
 import androidx.fragment.app.Fragment
 import com.sijanneupane.mvvmnews.R
+import com.sijanneupane.mvvmnews.ui.MainActivity
+import com.sijanneupane.mvvmnews.ui.NewsViewModel
 
 class SearchNewsFragment : Fragment (R.layout.fragment_search_news) {
+
+    lateinit var viewModel: NewsViewModel
+
+    override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
+        super.onViewCreated(view, savedInstanceState)
+
+        //set viewModels to fragment activity
+        //and we cast that as MainActivity so that we can have access to the view model created at MainActivity
+        viewModel= (activity as MainActivity).viewModel
+    }
 }

app/src/main/java/com/sijanneupane/mvvmnews/utils/Resource.kt

@@ -0,0 +1,28 @@
+package com.sijanneupane.mvvmnews.utils
+/*
+RESOURCE:
+recommended by google
+to wrap around network responses
+
+this will be an generic class
+very useful to differentiate between success and error responses
+and also helps in handling the loading state
+ */
+/*
+SEALED CLASS:
+kind of an abstract class where we can define which class are allowed to inherit the from this Resource Class
+ */
+sealed class Resource<T>(
+    //parameters
+    val data: T?=null,
+    val message: String?= null,
+
+        ){
+
+    //classes allowed to inherit
+    class Success<T>(data: T) : Resource<T>(data)
+    class Error<T>(message: String, data: T?= null): Resource<T>(data, message)
+    class Loading<T>: Resource<T>()
+
+
+}