add ListNotInRemoteChatPostsViewModel #5

Author: VeeShostak

app/src/main/java/io/github/veeshostak/aichat/database/dao/ChatPostDao.java

@@ -1,5 +1,6 @@
 package io.github.veeshostak.aichat.database.dao;
 
+import android.arch.lifecycle.LiveData;
 import android.arch.persistence.room.Dao;
 import android.arch.persistence.room.Delete;
 import android.arch.persistence.room.Insert;
@@ -22,7 +23,7 @@
 public interface ChatPostDao {
 
  @Insert(onConflict = OnConflictStrategy.ABORT)
- void insertChatMessages(ChatPost... chatPosts); // array of chatPosts (0 or more)
+ void insertChatPosts(ChatPost... chatPosts); // array of chatPosts (0 or more)
 
  @Update
  void updateChatPosts(ChatPost... chatPosts);
@@ -34,15 +35,15 @@ public interface ChatPostDao {
  // Each @Query method is verified at compile time. (Room also verifies the return value of the query)
 
  @Query("SELECT * FROM chat_posts")
- List<ChatPost> getAllChatPosts();
+ LiveData<List<ChatPost>> getAllChatPosts();
 
  @Query("SELECT * FROM chat_posts WHERE pushed_to_remote_db = 0")
- List<ChatPost> getAllChatPostsNotInRemoteDb();
+ LiveData<List<ChatPost>> getAllChatPostsNotInRemoteDb();
 
  @Query("DELETE FROM chat_posts")
- int deleteAllChatPosts(); // return # of deleted rows
+ void deleteAllChatPosts();
 
- @Query("SELECT * FROM chat_posts WHERE user_query = :userQuery LIMIT 1")
- ChatPost getChatPostWithUserQuery(String userQuery);
+// @Query("SELECT * FROM chat_posts WHERE user_query = :userQuery LIMIT 1")
+// ChatPost getChatPostWithUserQuery(String userQuery);
 
 }

app/src/main/java/io/github/veeshostak/aichat/viewmodels/ListNotInRemoteChatPostsViewModel.java

@@ -0,0 +1,61 @@
+package io.github.veeshostak.aichat.viewmodels;
+
+import android.app.Application;
+import android.arch.lifecycle.AndroidViewModel;
+import android.arch.lifecycle.LiveData;
+import android.os.AsyncTask;
+
+import java.util.List;
+
+import io.github.veeshostak.aichat.database.AppDatabase;
+import io.github.veeshostak.aichat.database.entity.ChatPost;
+
+/**
+ * Created by vladshostak on 12/26/17.
+ */
+
+public class ListNotInRemoteChatPostsViewModel extends AndroidViewModel {
+
+ private AppDatabase appDatabase;
+
+ private LiveData<List<ChatPost>> notInRemoteChatPostsList;
+
+ public ListNotInRemoteChatPostsViewModel(Application application) {
+ super(application);
+ // get instance of our db
+ appDatabase = AppDatabase.getDatabase(this.getApplication());
+ // Set ChatPosts. Live Data runs the query asynchronously on a background thread
+ notInRemoteChatPostsList = appDatabase.chatPostDao().getAllChatPostsNotInRemoteDb();
+ }
+ // Live Data runs the query asynchronously on a background thread
+ public LiveData<List<ChatPost>>getAllChatPostsNotInRemoteDb() {
+ return appDatabase.chatPostDao().getAllChatPostsNotInRemoteDb();
+ }
+
+ // Get chatPosts. Live Data runs the query asynchronously on a background thread
+ public LiveData<List<ChatPost>> getData() {
+ if (notInRemoteChatPostsList == null) {
+ notInRemoteChatPostsList = appDatabase.chatPostDao().getAllChatPostsNotInRemoteDb();
+ }
+ return notInRemoteChatPostsList;
+ }
+
+
+ // delete doesnt use liveData, execute in another thread. (Live Data runs the query asynchronously on a background thread when needed)
+ public void deleteItem(ChatPost toDeleteChatPost) {
+ new ListNotInRemoteChatPostsViewModel.DeleteAsyncTask(appDatabase).execute(toDeleteChatPost);
+ }
+ private static class DeleteAsyncTask extends AsyncTask<ChatPost, Void, Void> {
+ private AppDatabase appDb;
+ DeleteAsyncTask(AppDatabase appDatabase) {
+ appDb = appDatabase;
+ }
+ @Override
+ protected Void doInBackground(final ChatPost... params) {
+ appDb.chatPostDao().deleteChatPosts(params[0]);
+ return null;
+ }
+ }
+
+
+}