A SOAP web service is an XML based protocol used for communication between applications. It is platform and language independent and works over the HTTP protocol. It also defines its own security known as WS Security. The web services can be built on any programming language and execute on any platform.
The XML is a data interchange language that was developed to provide structured information and documents that are easy to use for both humans and software programs. The XML is a light weight format which is recommended by the W3C consortium that governs all the web standards.
There are two main components in the XML document which are – Envelope element and Body element. The first element – Envelope identifies the XML document as a SOAP message and contains all the details which is needed in order to send the SOAP message to the calling application. The Body element contains the actual data which needs to be sent between the web service and the calling application.
Another component of the XML document is – Header element which contains the details which are required to be defined by the web service as well as the client application. It also encapsulates the authentication information which is required by both the endpoints in the XML document. It can also be used to define complex data types which are not in the XML document itself.
A proxy is a layer of code that stands in place of the client application before making calls to the web service. The proxy takes the codes, wraps them and then sends them in proper format to the server. Once the server returns the SOAP package to the proxy, it decodes all the elements and then presents it to the client application which makes a call to the web service.
Using a proxy is an excellent way to build SOAP based web services as it is a simple and efficient process. Moreover, this is a great option for people who have limited knowledge about the technicalities involved in creating a SOAP based web service in asp.net.
This method is supported by all versions of ASP.NET and is a good option for beginners as it is fast, reliable and simple. Besides, it is free to use and is not limited by the license of the ASP.NET Framework or other third-party software which may be required by the developer.
You can create a SOAP webservice in any programming language such as C# or Java or any other.NET language and it will work on any platforms as long as they are running on an operating system such as Windows or Linux. Besides, it is very easy to develop such a service as there are a lot of examples and resources online that will help you develop the web service.
SOAP based web services are very useful as they offer clients the opportunity to remotely execute methods without downloading a separate API. This is an advantage over traditional web services which are based on RPC (Remote Procedure Call) style of communication.