Writing a Timer Job

Scenario:
You want to run some code on a regular interval and decided to write a timer Job.

Sample Timer Job Code:

using System;
using System.Net;
using Microsoft.SharePoint;
using Microsoft.SharePoint.Administration;

namespace SharePoint.TrainingSamples {

public class SharePointTimerJob:SPJobDefinition {

   public SharePointTimerJob():base(){ }

   public SharePointTimerJob(string jobName,SPWebApplication webApplication)
      :base(jobName, webApplication, null, SPJobLockType.ContentDatabase) {
      this.Title = "MyTimerJob";
  }

public override void Execute (Guid targetInstanceId) {
 foreach (SPSite siteCollection in this.WebApplication.Sites) {
   // Code to be executed as a part of Timer Job
foreach (SPSite siteCollection in this.WebApplication.Sites)
           {
               SPWebApplication webApplication = this.Parent as SPWebApplication;
               SPContentDatabase contentDb = webApplication.ContentDatabases[contentDbId];

               // get reference to "Tasks" list in the RootWeb of
               // the first site collection in the content database
               SPList taskList = contentDb.Sites[0].RootWeb.Lists["Tasks"];

               // create a new task, and update item
               SPListItem newTask = taskList.Items.Add();
               newTask["Title"] = DateTime.Now.ToString();
               newTask.Update();

           }
 }
}
}
}

Feature Activation Code:
Now that timer job is ready you need to add it to SharePoint Timer Jobs Store, One way is to add it as a part of Feature Activation

// get a reference to our job class in the GAC
public override void FeatureActivating (SPFeatureReceiverProperties properties) {

SPSite site = properties.Feature.Parent as SPSite;

//This is the timer class you have created above
SharePoint.TrainingSamples.SharePointTimerJob oSharePointTimerJob = new SharePoint.TrainingSamples.SharePointTimerJob("MyTimerJob", site.WebApplication);
// set the execution schedule to every 5 minute
SPMinuteSchedule schedule = new SPMinuteSchedule();
schedule.BeginSecond = 0;
schedule.EndSecond = 59;
schedule.Interval = 5;
oSharePointTimerJob.Schedule = schedule;
//update the job
oSharePointTimerJob.Update();
}

Feature De-Activation Code:
You might want to remove it from SharePoint Timer Jobs Store on de-activation

public override void FeatureDeactivating (SPFeatureReceiverProperties properties) {
 SPSite site = properties.Feature.Parent as SPSite;

 // Delete the job.
 foreach (SPJobDefinition job in site.WebApplication.JobDefinitions) {
   if (job.Name == "MyTimerJob")
     job.Delete();
 }
}

Articles:
MUST READ : Issues with Timer job , OTHER Helpful links MSDN , Must Read , Andrew Connell

Retrieving list items with CAML

Scenario:
You want to retrieve all the items of list

Code:

SPQuery qry = new SPQuery();

string camlquery =  "<OrderBy><FieldRef Name='Country' /></OrderBy><Where>"

   + "<Eq><FieldRef Name='LastName' /><Value Type='Text'>Sandeep</Value></Eq>"

   + </Where>";

qry.Query = camlquery;

Usage:
You can use the above 'qry' object in few different ways

SPListItemCollection listItemsCollection = list.GetItems(qry);

or

DataTable listItemsTable = list.GetItems(qry).GetDataTable();

Additonal Note: This query will return all the columns of the list, so if you are intrested in only a few of the columns then you can use

qry.ViewFields = "<FieldRef Name='FirstName' /><FieldRef Name='LastName' />";

Article:
http://sharepointmagazine.net/technical/development/writing-caml-queries-for-retrieving-list-items-from-a-sharepoint-list

Creating a Custom Action

feature.xml:

<?xml version="1.0" encoding="utf-8" ?>
<Feature Id="GUIDWithoutBraces"
   Title="Site Action Menu Custom Action"
   Description="This example shows how you can add new  menu to WSS Site Actions"
   Version="1.0.0.0"
   Scope="Site"
   xmlns="http://schemas.microsoft.com/sharepoint/">
 <ElementManifests>
   <ElementManifest Location="element.xml" />
 </ElementManifests>
</Feature>

element.xml:

<?xml version="1.0" encoding="utf-8" ?>
<Elements xmlns="http://schemas.microsoft.com/sharepoint/" >
<CustomAction Id="GUIDWithoutBraces"
   GroupId="SiteActions"
   Location="Microsoft.SharePoint.StandardMenu"
   Sequence="1000"
   Title="Configure Site"
   Description="Click on this link to configure extra settings."
   Rights="ViewUsageData"
   ImageUrl="_layouts/images/crtsite.gif">
    <UrlAction Url="~site/_layouts/Client/CustomPage.aspx"/>
 </CustomAction>

<CustomAction 
     Id="NEWGUID"
     Location="Microsoft.SharePoint.StandardMenu"
     GroupId="ActionsMenu"
     ControlAssembly="Training, Version=1.0.0.0, Culture=neutral, PublicKeyToken=0000000000000000"
     ControlClass="Training.NewMenuClass"> 
 </CustomAction>
</Elements>

CodeBehind.cs:

using System; 
using System.Collections.Generic; 
using System.Text; 
using Microsoft.SharePoint; 
using Microsoft.SharePoint.WebControls; 

namespace Training
{ 
 class NewMenuClass : System.Web.UI.WebControls.WebControl 
 { 
   protected override void CreateChildControls() 
   { 
     base.CreateChildControls(); 

     ToolBarMenuButton siteActionsControl = ToolBarMenuButton.GetMenuControl(this); 

     switch (siteActionsControl.List.RootFolder.Name) 
     { 
       case "Shared Documents": 
         { 
           Controls.Add(CreateMenuItem("MenuTitle", "Description", 100, "_layouts/custompage.aspx", "_layouts/images/logo.gif")); 
           break; 
         } 
     } 
   } 

private MenuItemTemplate CreateMenuItem(string Text, string Description, int Sequence, string OnClickUrl, string ImageUrl) 
   { 
     MenuItemTemplate menuItem = null; 
     menuItem = new MenuItemTemplate(); 
     menuItem.ID = Guid.NewGuid().ToString(); 
     menuItem.Text = Text; 
     menuItem.Description = Description; 
     menuItem.Sequence = Sequence; 
     menuItem.ClientOnClickNavigateUrl = OnClickUrl; 
     menuItem.ImageUrl = ImageUrl; 

     return menuItem; 
   } 
 } 
}

Notes:
Possible values for the 'Location' attribute:

Microsoft.SharePoint.ContentTypeTemplateSettings
Microsoft.SharePoint.ContentTypeSettings
Microsoft.SharePoint.Administration.ApplicationCreated
Office.Server.ServiceProvider.Administration (Shared Services/SSP links)
Microsoft.SharePoint.ListEdit.DocumentLibrary
Microsoft.SharePoint.Workflows
NewFormToolbar
DisplayFormToolbar
EditFormToolbar
Microsoft.SharePoint.StandardMenu (SiteActions menu)
Mcrosoft.SharePoint.Create (_layouts/create.aspx )
Microsoft.SharePoint.ListEdit (To edit the properties of a list item)
EditControlBlock (image below)

Articles:
http://blogs.breezetraining.com.au/mickb/2007/03/27/MOSSHowToAddActionsToTheUserInterface.aspx

http://blog.sharepointalist.com/2009/03/moss-central-admin-application-pages-p1.html

http://www.sharepointblogs.com/tanujashares/archive/2008/01/11/customize-the-oob-list-menus-in-sharepoint-2007-lists.aspx

Which assemblies need to be in SafeControl List

Doubt:
Why some assemblies need to be in SafeControl list , and other not.

Answer:
Assemblies using 'System.Web' namespace and 'Microsoft.SharePoint.WebControls' need to be in Safe Control list.

Deserializing XML file

Scenario:
You want to serialize the data from a class

XML:

<?xml version="1.0" encoding="utf-8"?>
<Address>
  <Address1>One Microsoft Way</Address1>
  <City>Redmond</City>
  <State>WA</State>
  <Zip>98052</Zip>
</Address>

Class:

public class Address {
  public string Address1;
  public string Address2;
  public string City;
  public string State;
  public string Zip;
}

Code:

Address oAddress = new Address();
XmlSerializer serializer = new XmlSerializer(typeof(Address));
FileStream file = new FileStream(@"c:\address.xml", FileMode.Open);
oAddress = serializer.Deserialize(file) as Address;

Serializing data

Scenario:
You want to serialize the data from a class

Class:

public class Address {
  public string Address1;
  public string Address2;
  public string City;
  public string State;
  public string Zip;
}

XML Output:

<?xml version="1.0" encoding="utf-8"?>
<Address>
  <Address1>One Microsoft Way</Address1>
  <City>Redmond</City>
  <State>WA</State>
  <Zip>98052</Zip>
</Address>

Code:

Address oAddress = new Address();
XmlSerializer serializer = new XmlSerializer(typeof(Address));
TextWriter writer = new StreamWriter(@"c:\addresses.xml");
serializer.Serialize(writer, oAddress);
writer.Close();

Site Template vs Site Definition

Site Definition Advantage:

• Data is stored directly on the Web servers, so performance is typically better.
• A higher level of list customization is possible through direct editing of a various XML files.
• Certain kinds of customization to sites or lists can only be done with site definitions, such as introducing new file types, defining view styles, or modifying the drop-down Edit menu.

Site definition Disadvantages:

• Customization of site definition requires more effort than creating custom templates. ( Not a big difference in effort if planning is proper )
• Users cannot apply a SharePoint theme through a site definition.
• Users cannot create two lists of the same type with different default content.
• Customizing site definitions requires access to the file system of the front-end Web server.

Site Templates Advantages:

• Site templates are easy to create.
• Almost anything that can be done in the user interface can be preserved in the template.
• Site templates can be modified without affecting existing sites that have been created from the templates.
• Site templates are easy to deploy (Basically just a file upload).

Site Template Disadvantages:

• Site templates are not created in a development environment.
• They are less efficient in large-scale environments, not very easy to move them across various environments.
• If the site definition on which the custom template is based does not exist on the front-end server or servers, the custom template will not work. The reason is that Site Template is a delta file applied on an existing Site Definition.