Book Exchange

Table of Contents

1. Overview
2. Product Spec
3. Wireframes
4. Schema

Overview

Description

Allows users to post and search for books they'd like to sell, trade, or buy.

App Evaluation

• Category: Shopping
• Mobile: Currently, this application is limited to mobile functionality, but future versions could include a web application.
• Story: Users can post books for sale/trade as well as search and shop for desired books.
• Market: Any user interested in buying, trading, or selling books.
• Habit: Users would use this as often as they needed to buy, sell, or trade books.
• Scope: Allowing users to connect and exchange books.

Product Spec

1. User Stories (Required and Optional)

Required Must-have Stories

Milestone 1

• User should be able to register an account
• User should be able to login
• Login should be persistent
• User should be able to log out

Milestone 2

• User should see top sellers on search screen (by default) before a query is sent
• User should be able to click on Best Seller images to search for those books
• Allow user to search by isbn

Milestone 3

• User should be able to post book for sale/trade/buy
• User should be able to autofill details for their book based on ISBN (with help of isbnDB API) to mitigate user input error

Milestone 4

• User should be able to click on any book listing for more detail

Optional Nice-to-have Stories

• Filter results by buy/sell/trade
• Compare against store listing price
• Users should be able to message seller/buyer to initiate sale
• Users should be able to see their current posts
• User should be able to delete their own posts
• User should be able to see previous sales/buys they've COMPLETED
• User should be able to rate transactions with others users
• User should be able to post book review
• User should be able to search by author/title

2. Screen Archetypes

• Login/Register
  • User should be able to register an account
  • User should be able to login
• Search Screen
  • User should see top sellers on search screen (by default) before a query is sent
  • Allow user to search by isbn
• Detailed Screen
  • User should be able to click on any book listing for more detail
• Post Book Screen
  • User should be able to post book for sale/trade/buy

3. Navigation

Tab Navigation (Tab to Screen)

• Logout
• Post

Flow Navigation (Screen to Screen)

• Login
  • Login (submit)
  • Register
• Search Screen
  • Search
  • Clicking on an individual listing will lead to Detailed Screen
• Detailed Screen
  • Back button (goes back to Search Screen)
• Post Book Screen
  • Post (submits new listing to our backend and returns)
• Confirmation screen
  • Back (Goes back to search screen-> stetch: display listing history)

Wireframes

Schema

Models

Property	Type	Description
objectId	String	Unique identifier
poster	pointer to User	Book listing author
image	String	URL of book cover
title	String	Title of book
author	String	Author of book
isbn	String	ISBN of book
details	String	Synopsis of book
cutom_details	String	User's description of the condition of the book they want to buy/sell/trade
type	String	Type of post (buy/sell/trade)
createdAt	Date	Date/time book listing was posted
updatedAt	Date	Date/time book listing was updated

Networking

List of network requests by screen

• Login

  • (Create/POST) Create a User object
  • (Read/GET) Authenticate User to login

• Search Screen

  • (Read/GET) Query posts to find book posts

      int LIMIT = 20;
      //specify which class to query
      ParseQuery<Post> query = ParseQuery.getQuery(Post.class);
      query.whereEqualTo("isbn", isbn);
      query.setLimit(LIMIT);
      // order by most recent
      query.addDescendingOrder(Post.KEY_CREATED_AT);
      // Retrieve all posts
      query.findInBackground(new FindCallback<Post>() {
          public void done(List<Post> resultPosts, ParseException e) {
              if (e == null) {
                  for(Post post : resultPosts) {
                      Log.i(TAG, "Post: " + post.getDescription());
                  }
              } else {
                  // something went wrong
                  Log.e(TAG, "Issue with getting posts", e);
              }
  
              posts.addAll(resultPosts);
              adapter.notifyDataSetChanged();
  
          }
      });

  • NYT Book API: Current Best Sellers: https://api.nytimes.com/svc/books/v3/lists/current/combined-print-and-e-book-fiction.json (For suggested books to search on Search screen)

      // Create our Async client so we can request from our API endpoint
      final AsyncHttpClient client = new AsyncHttpClient();
      // Get Books
      client.get(BEST_SELLER_URL, new JsonHttpResponseHandler() {
          @Override
          public void onSuccess(int statusCode, Headers headers, JSON json) {
              Log.d(TAG, "onSuccess");
              JSONObject jsonObject = json.jsonObject;
              try {
                  JSONObject results = jsonObject.getJSONObject("results");
                  JSONArray bookResults = results.getJSONArray("books");
                  Log.i(TAG, "Results: " + bookResults.toString());
                  books.addAll(Book.fromJsonArray(bookResults));
                  // Let adapter know when books updates to re-render
                  bookAdapter.notifyDataSetChanged();
  
              } catch (JSONException e) {
                  e.printStackTrace();
              }
              Log.i(TAG, "Books: " + books);
          }

• Detailed Screen

  • (Read/GET) Query Posts for selected book (by isbn)

• Post Book Screen

  • (Create/POST) Create a new Post object

      Post post = new Post();
      post.setCustomDescription(custom);
      post.setTitle(title);
      post.setISBN(isbn);
      post.setAuthor(author);
      post.setImgUrl(imgUrl);
      post.setPoster(user);
      post.setType(type);
  
      post.saveInBackground(new SaveCallback() {
          @Override
          public void done(ParseException e) {
              if(e != null){
                  // there's a problem
                  Log.e(TAG, "Problem saving post", e);
                  Toast.makeText(getContext(), "Problem saving post", Toast.LENGTH_SHORT).show();
  
              }
              else {
  
                  Log.i(TAG, "Post saved");
                  etCustom.setText("");
                  etTitle.setText("");
                  etAuthor.setText("");
                  etImgURL.setText("");
                  etISBN.setText("");
  
  
              }
          }

  • isbnDB API: Search by ISBN: https://api2.isbndb.com/book/{isbn} (to autofill book details based on ISBN for user posts)

       private void autoFillFromISBNDB(String isbn) throws MalformedURLException, ProtocolException, IOException {
          String url = "https://api2.isbndb.com/book/";
    
          try {
    
              URL myurl = new URL(url + isbn);
              con = (HttpURLConnection) myurl.openConnection();
              con.setRequestProperty("Content-Type", "application/json");
              con.setRequestProperty("Authorization", BuildConfig.ISBN_API_KEY);
              con.setRequestMethod("GET");
    
              StringBuilder content;
    
              try (BufferedReader in = new BufferedReader(
                      new InputStreamReader(con.getInputStream()))) {
    
                  String line;
                  content = new StringBuilder();
    
                  while ((line = in.readLine()) != null) {
                      content.append(line);
                      content.append(System.lineSeparator());
                  }
              }
    
              String c = content.toString();
              System.out.println(c);
    
              JSONObject reader = new JSONObject(c);
              JSONObject book = reader.getJSONObject("book");
              etTitle.setText(book.getString("title"));
              etImgURL.setText(book.getString("image"));
              JSONArray author = book.getJSONArray("authors");
              etAuthor.setText(author.get(0).toString());
    
    
              } catch (JSONException e) {
                  Toast.makeText(getContext(), "Sorry, we couldn't find that book to autoload info", Toast.LENGTH_SHORT).show();
                  e.printStackTrace();
              } finally {
    
                   con.disconnect();
          }
      }