Web services explained

What is a SOAP web service?

XML Web Services are modular, self-describing applications that can be published, located and invoked from anywhere on the web.

The beauty of web services is that neither the consumer nor the provider need worry about the operating system, language environment, or component model used to access them.

In fact, all you need to use a web service is an Internet connection and a browser.

What technologies are involved in Web Services?

XML, SOAP and HTTP are the base technologies of Web services architecture.

XML (Extensible Markup Language) is a W3C initiative that allows information and services to be encoded with meaningful structure and semantics that computers and humans can understand. XML is especially useful for information exchange and it is used by Web services to pass data and/or instructions back and forth between the provider and the consumer of the Web service.

SOAP (Simple Object Access Protocol) is a messaging protocol between computers e.g. the protocol that allows your computer to talk to the ePostcode server and vice-versa. It is a simple wire protocol that is based on XML and it allows remote computers to connect regardless of their operating system, programming language, or object model utilised.

HTTP (The Hypertext Transfer Protocol) is the set of rules for exchanging files (text, graphic images, sound, video, and other multimedia files) on the World Wide Web. Relative to the TCP/IP suite of protocols (which are the basis for information exchange on the Internet), HTTP is an application protocol. Because web services and SOAP use the HTTP protocol to exchange information there are no problems passing through locked down firewalls.

How can I use the ePostcode web service?

It's actually very simple. There are currently two separate web services for epostcode.

The URL address of the current range of epostcode web services can be found at: http://ws.epostcode.com/uk/postcodeservices13.asmx?wsdl

This is the most up to date web service and contains all the functions and features required for supporting Google map functionality and the ePostcode client application.

From the link above you can get a formal definition or Web Service Description Language (WSDL) of the service by clicking on the Service Description link. This WSDL is all that developers need to enable them to integrate the service into a website, intranet or desktop application.

If you are interested in integrating ePostcode have a look at our Developer section where you will find code samples and downloads that should help you to get started.

Why not have a go, it's a lot easier than you might think.