Flash® Builder™ 4 and Flex® 4 Bible

Chapter 25. Working with SOAP-Based Web Services

IN THIS CHAPTER

• Understanding SOAP

• Understanding WSDL

• Using the WebService component

• Handling WebService component events

• Calling Web service operations and displaying data with Flash Builder data connections

In Chapter 23, I described the use of the Flex HTTPService component to make requests and handle responses from Web resources formatted as arbitrary XML data structures. The strength of REST (Representational State Transfer) and generic XML is that you can create and use Web services that employ any arbitrary data structure. The potential weakness of this strategy is that each application must have specific knowledge of the particular XML structure being used.

SOAP-based Web services take a different approach: They employ industrystandard XML languages to format both messages and metadata. The SOAP language itself is used to format requests and responses between a client and a server, while WSDL (Web Services Description Language) is used to declare to Web service consumers the structure and capabilities of Web service operations

Note

The term SOAP started as an acronym for Simple Object Access Protocol. Starting with version 1.2, it became simply SOAP.

The strength of SOAP-based Web services lies in their industry-level standardization and their capability to accept strongly typed parameters and return values in a way that RESTful operations typically can't. Their weakness lies in the verbose nature of the messages that are exchanged ...