Essential SharePoint 2007, 2nd Edition

Using RPC

The SharePoint Remote Procedure Call (RPC) methods provide yet another way to change SharePoint sites and get content remotely. The RPC methods are similar to the URL commands discussed earlier, except RPC uses HTTP POST rather than GET to send requests.

Use RPC methods when you want to compose your changes or queries in Collaborative Application Markup Language (CAML) rather than through web service methods. CAML is a declarative approach to programming SharePoint using XML rather than a procedural programming language such as Visual Basic .NET. There are several advantages to this approach:

• RPC methods can be included on a web page as content rather than as server-side code.

• Users can compose and run their own queries in CAML without installing web parts or other code on the server.

• SharePoint templates and descriptions are in CAML, so understanding it helps you create custom site definitions.

• RPC incurs less overhead than web services.

That said, CAML is another skill to learn—and a fairly advanced one at that. RPC is the logical choice for customizing a SharePoint site without using web parts.

Table 12-8 lists the methods available through RPC. The URL commands are also available through RPC but aren't included in the table since they are already listed in Table 12-6.

Table 12-8. SharePoint RPC methods

Method	Parameters	Use to
Cltreq	UL, STRMVER, ACT, URL	Perform web discussion operations such as adding, editing, or deleting a discussion associated with a web page or with a document ...