UNIT 5: APP INVENTOR 2 (LEARN TO MAKE YOUR OWN APP'S)

Amazon Book Store - App Inventor 2 - Advanced Tutorial

 

Suppose that you’re browsing books at your favorite bookstore and want to know how much a book costs on

Amazon.com. With the Amazon at the Bookstore app, you can scan a book or enter an ISBN, and the app will

tell you the current lowest price of the book at Amazon.com. You can also search for books on a particular

topic.

 

Amazon at the Bookstore demonstrates how you can use App Inventor to create apps that talk to web services (aka, application programming interfaces, or APIs). This app will get data from a web service created by one of the authors of this book. By the end of this Tutorial, you’ll be able to create your own custom app for talking to Amazon.

 

The application has a simple user interface with which the user can enter keywords or a book’s ISBN (international standard book number—a 10- or 13-digit code that uniquely identifies a book) and then lists the title, ISBN, and lowest price for a new copy at Amazon. It also uses the BarcodeScanner component so that the user can scan a book to trigger a search instead of entering text (technically, the scanner just inputs the book’s ISBN for you).

 

What You’ll Learn

 

In this app, you’ll learn:

 

• How to use a barcode scanner within an app.

 

• How to access a web information source (Amazon’s API) through the TinyWebDB component.

 

• How to process complex data returned fromthat web information source. In particular, you’ll learn

how to process a list of books in which each book is itself a list of three items (title, price, and ISBN).