Using external Web services in Domino 6

What is a Web service?

Web services allow organizations to extend existing business processes to services that are published. Developers use these services to build loosely coupled software components, while facilitating information exchange and integration between applications. Unlike web-based traditional Domino applications, Web services do not have a user interface for end-user operations, but provide a unified approach to executing processes and exchanging data.

Web services are based on the following three technical standards:

Extensible Markup Language (extensible Markup Language, XML), which is the driving force behind Web services. XML language is not a programming language or API, but a platform-independent way of organizing data. The syntax of XML facilitates the processing of text data by programming and is easily understood by people. Web services use XML as the standard for communicating between network devices.

The Simple Object Access Protocol (easy access Protocol, SOAP) enables developers to remotely invoke methods of distributed objects using this platform-independent mechanism. The communication of SOAP messages uses XML to describe objects, methods, and parameters for execution. Both the client and the server can implement and use SOAP. In this way, the Soapconnect for LotusScript package makes it easy to use its implementation, and developers can do without processing the underlying XML.

The Web Services Description Language (Web Service Description language,wsdl) defines the ports and operations available in the Web service. You can think of a port as an interface, and an action as a method called on a particular object.

Book Catalog Cases

Before you look at the code and implementation details that use Soapconnect for LotusScript, let's introduce the purpose and structure of the sample database that is included. The sample database is a short book catalogue, including a variety of gardening books. The goal of the database is to allow users to get the latest prices for books in the category. The database contains a Form, called book, that includes each of the books in the category. The book form includes 5 fields to describe each: book title, book cover, book author, ISBN, publishing house. Users can view a list of available books through a Web browser, using the all book view, as shown in Figure 1 below.

As you might expect, after selecting a book in a view, users can see the details of the book.

For most online retailers, the price of books fluctuates with supply and demand. The user selects the Get Price button to obtain the latest prices. Here we use the Web services and Soapconnect for LotusScript packages provided by Barnes & Noble.