If your web application's success depends on how quickly and easily users can make transactions, then PayPal is a solution you can't afford to overlook. This book helps you determine which PayPal option is best for your situation, and provides step-by-step instructions for implementing the payment method you choose—whether you're accepting money via the Web or mobile devices for products and services, donations, or anything else. You'll find sample code written primarily in PHP and Objective-C, as well as use cases for executing options with PayPal's API. By the end of this book, you'll have a clear understanding of PayPal and how you can get the most out of its powerful features, no matter how much API programming experience you have. Learn how to work with the PayPal API, and choose the right integration method for your project Explore PayPal’s Express Checkout option, including its unique workflow and four methods of operation Examine the Website Payment Pro method—with a focus on direct payments Consider Adaptive Payments and learn how to set permission levels for their use Use PayPal in your iOS or Android-based mobile app with the new Mobile Express Checkout method Test your PayPal implementation with the sandbox

If your web application’s success depends on how quickly and easily users can make transactions, PayPal APIs provide effective solutions you can’t afford to overlook. This concise book takes you hands-on through several options to help you determine the best choice for your situation, whether you’re collecting money via websites or mobile apps for products and services, donations, or anything else. In each chapter, you’ll work with a different PayPal API by integrating it into the book’s sample application, using Python and the Google App Engine framework. This expanded edition introduces two new options: Express Checkout for Digital Goods and Instant Payment Notifications, complete with sample project code. By the end of this book, you’ll understand how to take full advantage of PayPal and its powerful features. Learn PayPal API basics, and get an introduction to Google App Engine Explore the Express Checkout option, and understand what distinguishes it from other generic workflows Tailor Express Checkout for electronic documents, videos, and other “in app” digital purchases Apply the Adaptive Payments option for transactions that involve multiple recipients Embed the payment process into your site with no mention of PayPal, using Website Payments Pro Use the Instant Payment Notifications you receive as triggers to take follow-up action

Shows developers how to harness the power of services such as Google, eBay, PayPal, and Amazon.com from within an application, whether it is Web-based, Windows-based, or even a Microsoft Office application After a quick review of the basics, readers will dive into more advanced techniques such as calling the APIs from mobile devices, Office VBA programs, Windows Forms and Web applications, and even how to integrate the various APIs together for a complete solution Veteran Wrox author Denise Gosnell skillfully guides readers through the ins and outs of the various services, the anatomy of an API query, which features are available via the APIs, and how to get results from their own applicationsReaders will build two fully functional applications to apply what they have learned-one a Windows program, the other a Web application

Features ready-to-use applications-all available on the CD-ROM-that eBay sellers can plug right into their pages; more advanced users can tweak the applications to suit specific needs Shows you how to streamline an eBay business by leveraging programming technologies and the eBay API (application program interface) Explains how to connect eBay pages to the APIs of related companies (PayPal, Fed Ex, UPS, and the USPS) as well as to Microsoft Office applications such as Outlook and Excel Provides expert tips and tricks for implementing eBay technologies such as image handling, shipping calculators, enhanced About Me pages, and back-office tools

If you've bought or sold items through eBay, or through hundreds of other online sites, then you're familiar with PayPal, the online payment service. With PayPal, a valid email address, and a credit card or bank account, you can easily send and receive payments online. Not a bank or financial institution itself, PayPal describes its service as one that builds on the financial infrastructure of bank accounts and credit cards, and using advanced propriety fraud prevention systems, creates a safe, global, real-time payment solution. Put simply, PayPal provides the means for people to conduct financial transactions online, instantly and securely.But there's more to PayPal than meets the eye. PayPal Hacks shows you how to make the most of PayPal to get the most out of your online business or transactions. Authors Shannon Sofield of Payloadz.com and PayPal evangelist David Nielsen guide you through the rigors of using and developing with PayPal. Whether you're building an ecommerce site using PayPal as a transaction provider, or simply trying to pay for an eBay auction without getting burned, PayPal Hacks will give you the skinny on this leading global online payment service.The collection of tips and tricks in PayPal Hacks shows you how to find or even build the right tools for using PayPal to buy and sell on eBay or as a transaction provider for ecommerce on your own site. Written for all PayPal users, from those just starting out to those developing sophisticated ecommerce sites, this book begins with the basics such as setting up your account, then moves quickly into specific tips and tools for buyers, sellers, and developers.With PayPal Hacks, you can: Learn extra steps to help protect yourself while buying or selling on eBay Save time and money with advanced tips and undocumented features Learn dozens of easy-to-follow procedures to help you request and receive payments and fill orders Use PayPal to handle subscriptions, affiliate systems, and donations Create and customize your customers' checkout process Effortlessly integrate PayPal's shopping cart system into your own website Implement digital fulfillment with Instant Payment Notification (IPN) and Payment Data Transfer (PDT) Develop and distribute ecommerce applications with the PayPal API Each hack consists of a task to be accomplished or a creative solution to a problem, presented in a clear, logical, and task-oriented format. PayPal Hacks provides the tools and details necessary to make PayPal more profitable, more flexible, and more convenient.

APIs are transforming the business world at an increasing pace. Gain the essential skills needed to quickly design, build, and deploy quality web APIs that are robust, reliable, and resilient. Go from initial design through prototyping and implementation to deployment of mission-critical APIs for your organization. Test, secure, and deploy your API with confidence and avoid the "release into production" panic. Tackle just about any API challenge with more than a dozen open-source utilities and common programming patterns you can apply right away. Good API design means starting with the API-First principle - understanding who is using the API and what they want to do with it - and applying basic design skills to match customers' needs while solving business-critical problems. Use the Sketch-Design-Build method to create reliable and scalable web APIs quickly and easily without a lot of risk to the day-to-day business operations. Create clear sequence diagrams, accurate specifications, and machine-readable API descriptions all reviewed, tested, and ready to turn into fully-functional NodeJS code. Create reliable test collections with Postman and implement proper identity and access control security with AuthO-without added cost or risk to the company. Deploy all of this to Heroku using a continuous delivery approach that pushes secure, well-tested code to your public servers ready for use by both internal and external developers. From design to code to test to deployment, unlock hidden business value and release stable and scalable web APIs that meet customer needs and solve important business problems in a consistent and reliable manner.

If your web application's success depends on how quickly and easily users can make transactions, PayPal APIs provide effective solutions you can't afford to overlook. This concise book takes you hands-on through several options to help you determine the best choice for your situation, whether you're collecting money via websites or mobile apps for products and services, donations, or anything else. In each chapter, you'll work with a different PayPal API by integrating it into the book's sample application, using Python and the Google App Engine framework. This expanded edition introduces two new options: Express Checkout for Digital Goods and Instant Payment Notifications, complete with sample project code. By the end of this book, you'll understand how to take full advantage of PayPal and its powerful features. Learn PayPal API basics, and get an introduction to Google App Engine Explore the Express Checkout option, and understand what distinguishes it from other generic workflows Tailor Express Checkout for electronic documents, videos, and other "in app" digital purchases Apply the Adaptive Payments option for transactions that involve multiple recipients Embed the payment process into your site with no mention of PayPal, using Website Payments Pro Use the Instant Payment Notifications you receive as triggers to take follow-up action

Languages may come and go, but the relational database endures. Learn how to use Ecto, the premier database library for Elixir, to connect your Elixir and Phoenix apps to databases. Get a firm handle on Ecto fundamentals with a module-by-module tour of the critical parts of Ecto. Then move on to more advanced topics and advice on best practices with a series of recipes that provide clear, step-by-step instructions on scenarios commonly encountered by app developers. Co-authored by the creator of Ecto, this title provides all the essentials you need to use Ecto effectively. Elixir and Phoenix are taking the application development world by storm, and Ecto, the database library that ships with Phoenix, is going right along with them. There are plenty of examples that show you the basics, but to use Ecto to its full potential, you need to learn the library from the ground up. This definitive guide starts with a tour of the core features of Ecto - repos, queries, schemas, changesets, transactions - gradually building your knowledge with tasks of ever-increasing complexity. Along the way, you'll be learning by doing - a sample application handles all the boilerplate so you can focus on getting Ecto into your fingers. Build on that core knowledge with a series of recipes featuring more advanced topics. Change your pooling strategy to maximize your database's efficiency. Use nested associations to handle complex table relationships. Add streams to handle large result sets with ease. Based on questions from Ecto users, these recipes cover the most common situations developers run into. Whether you're new to Ecto, or already have an app in production, this title will give you a deeper understanding of how Ecto works, and help make your database code cleaner and more efficient. What You Need: To follow along with the book, you should have Erlang/OTP 19+ and Elixir 1.4+ installed. The book will guide you through setting up a sample application that integrates Ecto.

You want increased customer satisfaction, faster development cycles, and less wasted work. Domain-driven design (DDD) combined with functional programming is the innovative combo that will get you there. In this pragmatic, down-to-earth guide, you'll see how applying the core principles of functional programming can result in software designs that model real-world requirements both elegantly and concisely - often more so than an object-oriented approach. Practical examples in the open-source F# functional language, and examples from familiar business domains, show you how to apply these techniques to build software that is business-focused, flexible, and high quality. Domain-driven design is a well-established approach to designing software that ensures that domain experts and developers work together effectively to create high-quality software. This book is the first to combine DDD with techniques from statically typed functional programming. This book is perfect for newcomers to DDD or functional programming - all the techniques you need will be introduced and explained. Model a complex domain accurately using the F# type system, creating compilable code that is also readable documentation---ensuring that the code and design never get out of sync. Encode business rules in the design so that you have "compile-time unit tests," and eliminate many potential bugs by making illegal states unrepresentable. Assemble a series of small, testable functions into a complete use case, and compose these individual scenarios into a large-scale design. Discover why the combination of functional programming and DDD leads naturally to service-oriented and hexagonal architectures. Finally, create a functional domain model that works with traditional databases, NoSQL, and event stores, and safely expose your domain via a website or API. Solve real problems by focusing on real-world requirements for your software. What You Need: The code in this book is designed to be run interactively on Windows, Mac and Linux.You will need a recent version of F# (4.0 or greater), and the appropriate .NET runtime for your platform.Full installation instructions for all platforms at fsharp.org.

Property-based testing helps you create better, more solid tests with little code. By using the PropEr framework in both Erlang and Elixir, this book teaches you how to automatically generate test cases, test stateful programs, and change how you design your software for more principled and reliable approaches. You will be able to better explore the problem space, validate the assumptions you make when coming up with program behavior, and expose unexpected weaknesses in your design. PropEr will even show you how to reproduce the bugs it found. With this book, you will be writing efficient property-based tests in no time. Most tests only demonstrate that the code behaves how the developer expected it to behave, and therefore carry the same blind spots as their authors when special conditions or edge cases show up. Learn how to see things differently with property tests written in PropEr. Start with the basics of property tests, such as writing stateless properties, and using the default generators to generate test cases automatically. More importantly, learn how to think in properties. Improve your properties, write custom data generators, and discover what your code can or cannot do. Learn when to use property tests and when to stick with example tests with real-world sample projects. Explore various testing approaches to find the one that's best for your code. Shrink failing test cases to their simpler expression to highlight exactly what breaks in your code, and generate highly relevant data through targeted properties. Uncover the trickiest bugs you can think of with nearly no code at all with two special types of properties based on state transitions and finite state machines. Write Erlang and Elixir properties that generate the most effective tests you'll see, whether they are unit tests or complex integration and system tests. What You Need Basic knowledge of Erlang, optionally ElixirFor Erlang tests: Erlang/OTP >= 20.0, with Rebar >= 3.4.0For Elixir tests: Erlang/OTP >= 20.0, Elixir >= 1.5.0