Saturday, September 25, 2010

Creating a List Item programmatically using the object model

The below code shows how to create a List Item programmatically using the object model in SharePoint 2007.

Adding a List Item to a Custom List

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using (SPWeb web = siteCollection.AllWebs["webname"])
  SPList list = web.Lists["Custom List"];
  SPListItem item = list.Items.Add();
  item["Title"] = "New List Item";

Optimised Adding a List Item to a Custom List

Use the following to add an item to a list:
Unable to find source-code formatter for language: csharp. Available languages are: actionscript, html, java, javascript, none, sql, xhtml, xml
01: public static SPListItem OptimizedAddItem(SPList list)
02: {
03: const string EmptyQuery = "0";
04: SPQuery q = new SPQuery {Query = EmptyQuery};
05: return list.GetItems(q).Add();
06: }
Do not use SPList.Items.Add as this will get all items in the list before adding a new SPListItem.
Source: Aidan Garnish

Adding a List Item to a Custom List with an Attachment

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using (SPWeb web = siteCollection.AllWebs["webname"])
  SPList list = web.Lists["Custom List"];
  SPListItem item = list.Items.Add();
  item["Title"] = "New List Item";

  SPAttachmentCollection attachments = item.Attachments;
  attachments.Add(fileName, byteArrayContents);


Adding a List Item to a Publishing Page Library

using (SPSite site = new SPSite("http://moss"))
    using (SPWeb web = site.OpenWeb())
        PublishingSite pSite = new PublishingSite(site);
        SPContentType ctype = pSite.ContentTypes["Welcome Page"];
        PageLayoutCollection pageLayouts = pSite.GetPageLayouts(ctype, true);
        PageLayout pageLayout = pageLayouts.FirstOrDefault<PageLayout>(p => p.Name == "WelcomeSplash.aspx");
        PublishingWeb pWeb = PublishingWeb.GetPublishingWeb(web);
        PublishingPageCollection pPages = pWeb.GetPublishingPages();
        PublishingPage pPage = pPages.Add("Programmatic_Test.aspx", pageLayout);
        SPListItem newpage = pPage.ListItem;
        newpage["Title"] = "Page added programmatically";

        newpage.File.CheckIn("all looks good");
        newpage.File.Publish("all looks good");
NOTE: requires .NET 3.5 for System.Linq FirstOrDefault method, can be switched for a loop.
Source: sridhara

Adding a List Item to a Document Library with an attachment

Unable to find source-code formatter for language: csharp. Available languages are: actionscript, html, java, javascript, none, sql, xhtml, xml
  // Creates document in given list (root folder).
// Returns true if the file was created, false if it already
// exists or throws exception for other failure
protected bool CreateDocument( string sFilename, string sContentType, string sList)
        SPSite site = SPContext.Current.Site;

        using (SPWeb web = site.OpenWeb())
            SPList list = web.Lists[sList];
            // this always uses root folder
            SPFolder folder = web.Folders[sList];
            SPFileCollection fcol = folder.Files;

            // find the template url and open
            string sTemplate = list.ContentTypes[sContentType].DocumentTemplateUrl;
            SPFile spf = web.GetFile(sTemplate);
            byte[] binFile = spf.OpenBinary();
            // Url for file to be created
            string destFile = fcol.Folder.Url + "/" + sFilename;

            // create the document and get SPFile/SPItem for
            // new document
            SPFile addedFile = fcol.Add(destFile, binFile, false);

            SPItem newItem = addedFile.Item;
            newItem["ContentType"] = sContentType;
            return true;
    catch (SPException spEx)
        // file already exists?
        if (spEx.ErrorCode == -2130575257)
            return false;
            throw spEx;
This code:
1. Gets a SPSite for the current site collection, and opens an SPWeb for the site.
2. Gets a SPList for the given list, and then an SPFolder for the root folder in this list. This code always creates the document in the root folder, but the code can easily be changed to place the document in any folder in the document library.
3. Gets a SPFileCollection for the documents in the folder.
4. "DocumentTemplateUrl" is used to return the Url of document template associated with the given content type.
5. Get an SPFile for the document template in spf and open it for binary access using OpenBinary
6. Add a new document to the folder through the SPFileCollection referenced by fcol.
7. Get an SPItem for the new document and set the "ContentType" column to ensure it uses the correct content type (it will default to the first content type in the document library).
8. Update the item and the added file.
9. The catch section checks for an -2130575257 error, which indicates the file already exists.

Adding a List Item to a Calendar List

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SPList cal = site.Lists["Calendar"];
SPListItem calEvent = cal.Items.Add();
calEvent["Title"] = "Frequent Event";
string recurrence = "<recurrence><rule>" +
"<firstDayOfWeek>su</firstDayOfWeek>" +
"<repeat><daily dayFrequency='2?/></repeat>" +
"<windowEnd>2010-09-20T09:00:00Z</windowEnd>" +
calEvent["RecurrenceData"] = recurrence;
calEvent["EventType"] = 1;
calEvent["EventDate"] = new DateTime(2009, 1, 26, 8, 0, 0);
calEvent["EndDate"] = new DateTime(2009, 1, 26, 9, 0, 0);
calEvent["UID"] = System.Guid.NewGuid();
calEvent["TimeZone"] = 13;
calEvent["Recurrence"] = -1;
Note that the CAML to create the recurrence can be complicated so please take a look at the MSDN article.

Adding a List Item to a List in SharePoint 2010

In SharePoint 2010 you can use the following code to add an item to a SPList in an optimized way:
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using (SPWeb web = SPContext.Current.Web)
  SPList list = web.GetList(string.concat(web.Url, "/Lists/Custom List"));
  SPListItem item = list.AddItem();
  item["Title"] = "New List Item";

Use PowerShell to Manage Lists, Views, and Items in SharePoint 2010

Creating Lists in SharePoint 2010
One of the most powerful features of SharePoint from an end user’s perspective is the ease of creating and customizing lists, views, and items. Lists store data. SharePoint 2010 includes a large number of list templates that can be used as they are or as a starting point to tailor them to fulfill your specific business requirements. Lists have a set of configurable settings that apply to all lists, as well as custom settings that apply only to the specific type of list used.
Let’s take a look at the templates available. We can do this using the ListTemplates property on an object of the type SPWeb. First, we store an object of the type SPWeb in a variable:
PS > $spWeb = Get-SPWeb -Identity http://SPServer
Next, we use the ListTemplates property and select the name and description, as shown in the following image.
Image of selecting name and description with ListTemplates property
We can use a template when creating a new list (of course we’ll do this by using Windows PowerShell). When creating a list in SharePoint 2010, you use the Add method of the SPListCollection class. This method has seven overloads (method signatures, or ways in which the method can be called). The one we will be using for our example accepts three parameters: the list title, description, and template type to be used. The title and description parameters are both of the type System.String, and the template parameter is of the type SPListTemplateType, so we need to provide an instance of this type as a value for this parameter.
Here, we create a variable containing the Contacts list template type, which we obtain from the Microsoft.SharePoint.SPListTemplateType enumeration:
PS > $listTemplate = [Microsoft.SharePoint.SPListTemplateType]::Contacts
PS > $spListCollection = $spWeb.Lists
PS > $spListCollection.Add("My Contacts","Description",$listTemplate)
Why do we need this intermediary spListCollection variable? Why not call the Add method directly with $spWeb.Lists.Add? If we used the Add method directly and repeated the command ten times, the metadata for all available lists in the site would be loaded ten times. Storing the lists collection in a variable and working with that variable minimizes the amount of memory consumed, because the lists are loaded only once.
Modifying Lists in SharePoint 2010
Let’s see how we can modify our new list. First, we get the list using the GetLists() method and store it in a variable:
PS > $spList = $spWeb.GetList("/Lists/My Contacts")
With the list stored in a variable, we can go ahead and set all kinds of cool stuff. Here’s how to add a list to the Quick Launch:
PS > $spList.OnQuickLaunch = "True"
PS > $spList.Update()
When you run the command above, the list appears on the Quick Launch. Setting the value to False hides the list from the Quick Launch. If we want to change the list’s description, we can simply use the Description property:
PS > $spList.Description = "My Contact List"
PS > $spList.Update()
Adding List Fields
It’s also possible to add additional fields to a list. To create a field in a SharePoint 2010 list, use the Add method provided by the SPFieldCollection class. Here, we create a simple Text type field in a SharePoint list:
PS > $spFieldType = [Microsoft.SharePoint.SPFieldType]::Text
PS > $spList.Fields.Add("TextField",$spFieldType,$false)
In this example, we create an SPFieldType object with the value Text and store it in the variable spFieldType. We then use the Add method and pass in the field’s display name, followed by the variable spFieldType, followed by Boolean False. The last parameter in this overload of the Add method specifies whether the new field is required to always contain a value. Our example creates a new text field in the list with the display name of TextField that will not require any input. An additional Boolean parameter you can use with the Add method compacts the field name to eight characters, if set to True.
SharePoint 2010 supports other types of fields as well. Adding a Choice field is a little different since it requires additional information regarding the possible choices. You can store the choices in an instance of the System.Collections.Specialized.StringCollection class, as shown in this example:
PS > $choices = New-Object System.Collections.Specialized.StringCollection
PS > $choices.Add("First Choice")
PS > $choices.Add("Second Choice")
PS > $choices.Add("Third Choice")
Now that we have our choices stored in a variable, we can use the variable when creating a Choice type field:
PS > $spFieldType = [Microsoft.SharePoint.SPFieldType]::Choice
PS > $spList.Fields.Add("ChoiceField",$spFieldType,$false,$false,$choices)
We use the choices variable to associate a list of options with the field.
Managing List Views
Let’s move on and look at how to manage list views in SharePoint 2010. Views enable you to create customized representations of list data for specific purposes, such as displaying specific fields. When a new list in SharePoint is created, a default view is added. Document Library lists get the All Documents view, Picture Library lists get the All Pictures view, and most of the other list types get the All Items view.
Before we can edit an existing view in SharePoint 2010, we need to retrieve it. We can use the GetViewFromUrl method of the SPWeb class. Let’s get the Contacts list we created earlier:
PS > $spView = $spWeb.GetViewFromUrl("/Lists/My Contacts/AllItems.aspx")
When new fields are created, they are not added to a view by default. We can, of course, add a field to a view by using Windows PowerShell. First, we need to create a reference to the field that we want to add to the view:
PS > $spField = $spList.Fields["TextField"]
We then can use the Add method provided by the SPViewFieldCollection class to add the field to a view and finally use the Update() method to set the changes:
PS > $spView.ViewFields.Add($spField)
PS > $spView.Update()
You can do a lot more cool stuff with views such as set custom queries, create new views, and remove views.
Managing List Items
Let’s move ahead and take a look at how to add list items to a list. The SPList class provides the AddItem method, which is used to create new list items. When you call the AddItem method, an object of the type Microsoft.SharePoint.SPListItem is returned. Because we want to populate the properties of the new list item, we need to store the object in a variable in order to continue to work with it:
PS > $spListItem = $spList.AddItem()
Now we can start assigning values to the different fields the corresponding list item inherits from the parent list. The SPListItem class provides a parameterized Item property for accessing the value contained in a particular field. To specify the value of the Title field, we can use the following:
PS > $spListItem["Title"] = "New Item"
We can assign additional values to fields as well. In the next example, we add values to the TextField and ChoiceField, which we created earlier in this example:
PS > $spListItem["TextField"] = "Hey hey"
PS > $spListItem["ChoiceField"] = "First Choice"
Finally, we use the Update() method to create the new list item:
PS > $spListItem.Update()
What if we want to update an existing list item? Well, the SPList class provides a few methods we can use to retrieve a specific from a list. The most common methods are GetItemById() and GetItems().
Wait a minute! Isn’t it simpler to loop through the Items collection and create a filter using the Where-Object cmdlet? It is simpler and does feel like the Windows PowerShell way of doing things, but consider this: When you use the Items property on an SPList object, all the list items in the list are read into memory, meaning that large lists may consume a lot of memory. A better approach is to use either the GetItemsById() method or the GetItems() method to minimize memory consumption.
The GetItemById() method requires that we know the ID of the particular item. In many cases, we have no idea of an item’s ID, but we might know the item’s title or some other value. This is where the GetItems() method becomes useful. The method returns all list items or a subset of list items as defined by search criteria in a CAML query.
To use a CAML query with the GetItems method, we first need to create an object of the type Microsoft.SharePoint.SPQuery:
PS > $spQuery = New-Object Microsoft.SharePoint.SPQuery
The SPQuery object supports the Query property, which we use to place a CAML query. Here’s the CAML query we’ll use in our example:
PS > $camlQuery =  >> ‘<Where><Eq><FieldRef Name="Title" /><Value Type="Text">True</Value></Eq></Where>'
We create a new query containing a Where statement using the <Where> tag. Next, we specify an equals expression using the <Eq> tag. For other types of searches, you can replace this tag with the appropriate one, such as <Lt> or <Gt> to search for list items where the value of this field is less than or greater than a value, respectively.
We then specify the field we want to query against using the <FieldRef> tag. In this example, we want to look at the Title field in the list. Finally, we use the <Value> tag to specify that the value type is Text and that the value should equal New Item.
After we have created a CAML query and stored it in a variable, we assign it to the Query property of our SPQuery object:
PS > $spQuery.Query = $camlQuery
Before using the SPQuery with the GetItems method, we should specify the RowLimit property that is used to limit the amount of items returned per page. If we run the SPQuery without setting the row limit, the query will select all items matching the criteria and might fail on lists with a large number of items:
PS > $spQuery.RowLimit = 100
Here, we set the RowLimit property to 100 so that only 100 list items are returned per page. The RowLimit value should be between 1 and 2000. Finally, we can call the GetItems() method with the SPQuery object instance we created earlier for input:
PS > $spListItem = $spList.GetItems($spQuery)
Now it’s a simple task to update the list item. In the example below, we change the item’s Title. Note that the GetItems() method returns a ListItemCollection, so even if only one value is returned, we still have to index the first element or use the ForEach-Object cmdlet to loop through each item:
PS > $spListItemCollection | ForEach-Object { >> $_["Title"] = "New Value"; $_.Update()  >>}
In this post, we’ve looked at how to manage lists, views, and items by using Windows PowerShell. We saw examples about how to create new lists, modify list properties, add fields, manage views, and how to work with items. Chapter 14 in PowerShell for SharePoint 2010 Administrators (available October 2010) takes list and view management one step further by showing how to manage lookup fields, how to retrieve lists using a simple function, how to automate list creation, and much more. In Chapter 15, you’ll see detailed examples about how to create, manage, delete, and copy list Items.

C# Code Performance Measurement

Many times we need to check the performance of the our C# code. so following is the workaround with an example. ..
Most developers prefer to use a foreach loop than for loop because foreach is easier to use. This will however prove to be costly when working with collections with a large amount of data. Consider the below sample in which I am looping through the same datatable using for and foreach. Also check the time taken by each loop on Fig 1.0.
  static void Main(string[] args)
      DataTable dt = PopulateData();
      Stopwatch watch = new Stopwatch();
      //For loop
      for (int count = 0; count < dt.Rows.Count; count++)
          dt.Rows[count]["Name"] = "Modified in For";
      Console.WriteLine("Time taken in For loop: {0}", watch.Elapsed.TotalSeconds);
      //Foreach loop
      foreach (DataRow row in dt.Rows)
          row["Name"] = "Modified in ForEach";
      Console.WriteLine("Time taken in For Each loop: {0}", watch.Elapsed.TotalSeconds);

Fig 1.0
As you can see the foreach loop is slow, it takes almost double the amount of time as that of the for loop. This is because in the foreach loop dt.Rows will access all the rows in the datatable.
For bigger collections always use for loop in case if looping is required.

C# Programming Tips and Tricks

C# is a great language. It is relatively easy to learn with its simpler syntax over C++ programming and Java. Ten years down the line it still is a strong competitor. It has had improvement year after year, with new features added with its every release. It has not disappointed the C# developer community.
No time to read prologue, right? I know. Let's jump straight in. 
1.   Environment.Newline
Did you know that this property is platform independent and allows you to output the new line characters as per the platform?
  Console.WriteLine("My Tips On ,{0}C#", Environment.NewLine);
Namespace Alias
Did you know that you can substitute your big namespaces with shorter aliases? Or have you faced a situation where you had to qualify the object with its complete namespace to avoid ambiguity.
Look at the sample below where there is a generic library created with extended .NET Framework controls.
                using System.Web.UI.WebControls;
                using MyGenericLibrary.UserControls;
           /* Assuming that you had a Text Box control in both the namespace, you would have to fully qualify  the class object with the complete namespace. To avoid that, you can use namespace alias. Change as below */
                using System.Web.UI.WebControls;
                using mc = MyGenericLibrary.UserControls;
          /*and then use, /*
                mc.TextBox textbox = new mc.TextBox();
  DebuggerBrowsable Attribute
Every C# developer does debugging at some point or the other. This attribute is very powerful in controlling the behavior of an object during the debugging process. The debugging process involves the display of the object being debugging in a small tooltip window.
It can be used to hide the private members, or other members that are considered to be useless in the debugging window, e.g. when you debug any class object you would see the private variables in the debugger window. You can hide it using the [DebuggerBrowsable(DebuggerBrowsableState.Never)] attribute.
  public class MyClass
      private string _id;
      public string InternalID
            get { return _id; }
            set { _id = value; }

  public class MyClass
      private string _id;
      public string InternalID
            get { return _id; }
            set { _id = value; }
  DebuggerDisplay Attribute
This attribute makes the display of the variable object with a readable description. It helps users who work on your projects in the future.
/It's simple to use. The following code shows the value of the variable.
                public class MyClass
             [DebuggerDisplay("Value = {myVariable}")]
                    public string myVariable = "mydisplay";
  Create Virtual Directory for the Project
You can force every developer in your team to create virtual directories with the same name for the project. This trick from the Microsoft Visual Studio IDE is extremely helpful in keeping code sync'd over several C# developer machines.
Right-Click on the project and choose "Properties" from the options. Under the web tab, choose the "Use Local IIS Web Server" option and provide the virtual path.

Figure 1
Make these changes and check in your project file. All developers who use the project file will be asked to create a virtual directory with the same name in their machines.
  Change the Project Platform
You can change the platform of the application that you are building and target all or specific platforms. The platforms here refer to the 32-bit and the 64-bit environments.
Right-Click on the project and choose "Properties" from the options. Under the "Build" tab, choose the appropriate "Platform".

Figure 2
Make these changes and check in your project file. All developers who use the project file will be asked to create a virtual directory with the same name in their machines.
  Code Definition Window
This window lets you navigate to the Definition of an object. You can press the F12 key to quickly navigate to the definition of an object. Try it on any object in your editor right now and you shall not be disappointed.
There is also the "CODE DEFINITION WINDOW". The key combination CTRL + W,D will bring up the code definition window for you.
                 if (e.Item.ItemType == ListItemType.Item )
                    //Your code here.
If you place the cursor on ListItemType word, and press the key combination you will see a window like the one below.

Figure 3
  Null Coalescing Operator
The null coalescing operator lets you compare against null in a short manner. It is represented using the double question mark notation.
For example, the myfunction whose return value may be a nullable int. In such cases, you can use the coalescing operator to quickly check if it is null and return an alternate value.
                int myExpectedValueIfNull = 10;
                int expectedValue = myfunction() ??   myExpectedValueIfNull
  Shortcut for Using Statement
Ctrl and "." brings up the window with the list of probable using statements. Use the arrow keys to select. Press enter. Voila! A using statement is added.

Figure 4
10·  Dreadful Dataset Merge Errors
Have you been unable to figure out why the dataset merges failed? There is a way out.
Yes, you have to wrap your code in try-catch. But watch out for the specific code in the exception handling block that captures the exact reason for the merge to fail.
        StringBuilder error Messages = new StringBuilder();
                       DataSet dataSet1 = populateDataSet(1);
               DataSet dataSet2 = populateDataSet(2);
                       catch (System.Data.DataException de)
      foreach (DataTable myTable in dataSet1.Tables)
         foreach (DataRow myRow in myTable.GetErrors())
            foreach (DataColumn myColumn in myRow.GetColumnsInError())
                //loop through each column in the row that has caused the error
                //during the bind and show it.
                 error Messages .Append(string.Format(
                  "Merge failed due to  : {0}", myColumn.GetColumnError(myColumn)));

If you have some tips and tricks you'd like to share please leave them in the comments or email them to me directly. Thanks for reading.