Android Studio Book search Google API

Question

OK This Android ( Java ) app searches the Google App API and displays books in a listview. It uses a custom adapter and a Async Loader. I have a skeleton of the app working, but just one search. After that everything just stays on the screen and the new search doesn't happen, or does not appear to happen.

I had it working from the MainActivity on create, but then moved it to a button and EditText.

I think the problems resides mostly here in this file.

If someone could help, it would be great! Look at last section under the goQuery button click. Thanks.

public class MainActivity extends AppCompatActivity implements LoaderCallbacks> { private static final String LOG_TAG = MainActivity.class.getName(); private String GOOGLE_REQUEST_URL = "https://www.googleapis.com/books/v1/volumes?q=android&maxResults=10"; /** * Constant value for the Book loader ID. We can choose any integer. * This really only comes into play if you're using multiple loaders. */ private static final int BOOK_LOADER_ID = 1;

/** Adapter for the list of books */
private BookWormAdapter mAdapter;

/** TextView that is displayed when the list is empty */
private TextView mEmptyStateTextView;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);


    ListView bookwormListView = (ListView) findViewById(R.id.list);

    mEmptyStateTextView = (TextView) findViewById(R.id.empty_view);
    bookwormListView.setEmptyView(mEmptyStateTextView);

    // Create a new adapter that takes an empty list of books as input
    mAdapter = new BookWormAdapter(this, new ArrayList<Book>());

    // Set the adapter on the {@link ListView}
    // so the list can be populated in the user interface
    bookwormListView.setAdapter(mAdapter);
    /// End Button search

    // Set an item click listener on the ListView, which sends an intent to a web browser
    // to open a website with more information about the selected book.
    bookwormListView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
        @Override
        public void onItemClick(AdapterView<?> adapterView, View view, int position, long l) {
            // Find the current book that was clicked on
            Book currentBook = mAdapter.getItem(position);

            // Convert the String URL into a URI object (to pass into the Intent constructor)
            Uri bookwormUri = Uri.parse(currentBook.getPreviewLink());

            // Create a new intent to view the book URI
            Intent websiteIntent = new Intent(Intent.ACTION_VIEW, bookwormUri);

            // Send the intent to launch a new activity
            startActivity(websiteIntent);
        }
    });

    View loadingIndicator = findViewById(R.id.loading_indicator);
    loadingIndicator.setVisibility(View.GONE);
}


@Override
public Loader<List<Book>> onCreateLoader(int i, Bundle bundle) {
    // Create a new loader for the given URL
    //Log.i(LOG_TAG, "onCreateLoader: TEST Created Loader!");
    return new BookWormLoader(this, GOOGLE_REQUEST_URL);
}



@Override
public void onLoadFinished(Loader<List<Book>> loader, List<Book> bookworms) {
    // Hide loading indicator because the data has been loaded
    View loadingIndicator = findViewById(R.id.loading_indicator);
    loadingIndicator.setVisibility(View.GONE);
    //  Log.i(LOG_TAG, "onLoadFinished: On Load finished!");
    // Set empty state text to display "No books found."
    mEmptyStateTextView.setText(R.string.no_books);

    // Clear the adapter of previous book data
    mAdapter.clear();

    // If there is a valid list of {@link Book}s, then add them to the adapter's
    // data set. This will trigger the ListView to update.
    if (bookworms != null && !bookworms.isEmpty()) {
        mAdapter.addAll(bookworms);
        //mAdapter.notifyDataSetChanged();
    }
}

@Override
public void onLoaderReset(Loader<List<Book>> loader) {
    // Loader reset, so we can clear out our existing data.
    mAdapter.clear();
    //  Log.i(LOG_TAG, "onLoaderReset: TEST On Loader Reset!");
}
public void goQuery(View view){
    EditText mySearchTextView = findViewById(R.id.searchEdit);

    `enter code here`if (mySearchTextView.getText().length() < 1) return;

    //mAdapter.clear();
  // mAdapter.notifyDataSetChanged();


    View loadingIndicator = findViewById(R.id.loading_indicator);
    loadingIndicator.setVisibility(View.VISIBLE);

    GOOGLE_REQUEST_URL = "https://www.googleapis.com/books/v1/volumes?q="+mySearchTextView.getText()+"&maxResults=20";

    // Get a reference to the ConnectivityManager to check state of network connectivity
    ConnectivityManager connMgr = (ConnectivityManager)
    getSystemService(Context.CONNECTIVITY_SERVICE);

    // Get details on the currently active default data network
    NetworkInfo networkInfo = connMgr.getActiveNetworkInfo();

    // If there is a network connection, fetch data
    if (networkInfo != null && networkInfo.isConnected()) {
        // Get a reference to the LoaderManager, in order to interact with loaders.
        android.app.LoaderManager loaderManager = getLoaderManager();

// Initialize the loader. Pass in the int ID constant defined above and pass in null for // the bundle. Pass in this activity for the LoaderCallbacks parameter (which is valid // because this activity implements the LoaderCallbacks interface). loaderManager.initLoader(BOOK_LOADER_ID, null, this); } else { // Otherwise, display error // First, hide loading indicator so error message will be visible loadingIndicator.setVisibility(View.GONE);

        // Update empty state with no connection error message
        mEmptyStateTextView.setText(R.string.no_internet_connection);
    }

}

}

Answer 1

I added this to the buttonClick and it is now working. Don't know if this is real Kosher?

loaderManager.destroyLoader(BOOK_LOADER_ID); mAdapter.clear(); mAdapter.notifyDataSetChanged()enter code here;