Web Services Uncovered: SharePoint 2007.

Today we are going to talk about the Web services in SharePoint. We all know SharePoint provide very extensive support for the web services, writing custom web services, we will try to compile some information on this. 

What is a web Service?

A Web service is a method of communication between two electronic devices over the Web (Internet).

The W3C defines a "Web service" as "a software system designed to support interoperable machine-to-machine interaction over a network". It has an interface described in a machine-processable format (specifically Web Services Description Language, known by the acronym WSDL). Other systems interact with the Web service in a manner prescribed by its description using SOAP messages, typically conveyed using HTTP with an XML serialization in conjunction with other Web-related standards.

What is SOAP? 

SOAP, originally defined as Simple Object Access Protocol, is a protocol specification for exchanging structured information in the implementation of Web Services in computer networks. It relies on Extensible Markup Language (XML) for its message format, and usually relies on other Application Layer protocols, most notably Hypertext Transfer Protocol (HTTP) and Simple Mail Transfer Protocol (SMTP), for message negotiation and transmission.

Web services protocol stack?

A web service protocol stack is a protocol stack (a stack of computer networking protocols) that is used to define, locate, implement, and make Web services interact with each other. A Web service protocol stack typically stacks four protocols:

• (Service) Transport Protocol: responsible for transporting messages between network applications and includes protocols such as HTTP, SMTP, FTP, as well as the more recent Blocks Extensible Exchange Protocol (BEEP).
• (XML) Messaging Protocol: responsible for encoding messages in a common XML format so that they can be understood at either end of a network connection. Currently, this area includes such protocols as XML-RPC, WS-Addressing, and SOAP.
• (Service) Description Protocol: used for describing the public interface to a specific Web service. The WSDL interface format is typically used for this purpose.
• (Service) Discovery Protocol: centralizes services into a common registry such that network Web services can publish their location and description, and makes it easy to discover what services are available on the network.

Web Services in SharePoint?

The web service .asmx files are located at "C:\Program Files\Common Files\Microsoft Shared\web server extensions\12\ISAPI"

Every SharePoint Site has a virtual directory known as "_vti_bin" which maps to the above directory.  Don't believe me?  Open up your IIS management console, go to one of your web apps, and look where "_vti_bin" maps to in the file system.

Here is a list of the web services:

Name	URL
Administration	http://<AdminSite>/_vti_adm/Admin.asmx
Alerts	http://<Site>/_vti_bin/Alerts.asmx
Authentication	http://<Site>/_vti_bin/Authentication.asmx
Copy	http://<Site>/_vti_bin/Copy.asmx
Document Workspace	http://<Site>/_vti_bin/Dws.asmx
Forms	http://<Site>/_vti_bin/Forms.asmx
Imaging	http://<Site>/_vti_bin/Imaging.asmx
List Data Retrieval	http://<Site>/_vti_bin/DspSts.asmx
Lists	http://<Site>/_vti_bin/Lists.asmx
Meetings	http://<Site>/_vti_bin/Meetings.asmx
People	http://<Site>/_vti_bin/People.asmx
Permissions	http://<Site>/_vti_bin/Permissions.asmx
SharePoint Directory Management	(in stssoap.dll)
Site Data	http://<Site>/_vti_bin/SiteData.asmx
Sites	http://<Site>/_vti_bin/Sites.asmx
Search	http://<Site>/_vti_bin/spsearch.asmx
Users and Groups	http://<Site>/_vti_bin/usergroup.asmx
Versions	http://<Site>/_vti_bin/Versions.asmx
Views	http://<Site>/_vti_bin/Views.asmx
Web Part Pages	http://<Site>/_vti_bin/WebPartPages.asmx
Webs	http://<Site>/_vti_bin/Webs.asmx

SharePoint has a rich list of Web Services it support so it is always good to keep handy the SharePoint Web Services Link provided by Microsoft, http://msdn.microsoft.com/en-us/library/ms445292.aspx

 

A nice reference to the well explained Architecture of Web services by Trent Swanson: http://www.infoq.com/articles/swanson-moss-web-services.

You nice video on calling web services  using silver light application: http://www.youtube.com/watch?v=_-Z30-1sdXY

If you have any queries/questions regarding the above mentioned information then please let me know. Thank you.