SharePoint Client Object Model using ECMAScript - End User - NothingButSharePoint.com

SharePoint Client Object Model using ECMAScript - End User - NothingButSharePoint.com

ECMAScript Class Library

Following is the refrence to SHarePoint 2010 ECMA Script Class Library:

URL: http://msdn.microsoft.com/en-us/library/ee538253.aspx

SharePoint Client Object Model vs Server Object Model Classes

One of the new feature of SharePoint 2010 is the Client Object Model. By using Client Object Model, developers can build the applications which can talk to SharePoint without using WebServices and without deploying any server side code.

Following is the list of Client Object Model classes and their equivalent to Server Object Model classes:

Client Object Model	Server Object Model
ClientContext	SPContext
Site	SPSite
Web	SPWeb
List	SPList
ListItem	SPListItem
Field	SPField

Example:

using Microsoft.SharePoint.Client;

private void SomeMethod()
{
  ClientContext clientContext = new ClientContext(siteUrl);
  Site siteCollection = clientContext.Site;
  Web site = clientContext.Web;
}

Ref: http://msdn.microsoft.com/en-us/library/ee857094(office.14).aspx

EMail as Primary Key in List

Problem:
I have been asked a question today from one of the developers in another team that he wants to create a user registration list where emial should be unique for every user. And if user add item with existing email then he should be informed.

Solution:
We know that this functionality does not exist in the OTB SharePoint list features. After googling a bit I found following excellent solution using JQuery:

URL: http://sharepointjavascript.wordpress.com/2009/11/23/sharepoint-lists-or-document-librarys-primary-key-in-selected-field/