<TokenReplacementFileExtensions>master</TokenReplacementFileExtensions>

Reload the project, rebuild the solution and create the package.

I combined the knowledge and insights of both posts into a solution for my problem. First of all you have to start a Project scoped as Farm Solution since we have to publish files into the Layouts folder. This javascript file can be added into the Layouts Mapped Folder very easy.

   1: function google_OpenModalDialog() {

   2:     var options = SP.UI.$create_DialogOptions();

   3:     options.width = 500;

   4:     options.height = 250;

   5:     options.url = "http://www.google.com/";

   6:     SP.UI.ModalDialog.showModalDialog(options);

   7: }

To publish the file in SharePoint, so you can reference methods of it you have to add a CustomAction.

   1: <CustomAction Location="ScriptLink" Sequence="1000"

   2:               ScriptSrc="PlayingWithSiteActions/OpenModalDialog.js">

   3: </CustomAction>

Finally you can add another CustomAction to display a link under Site Actions a reference the javascript method when clicked on it.

   1: <CustomAction Id="SiteActionsToolbar" GroupId="SiteActions" Location="Microsoft.SharePoint.StandardMenu"

   2:               Sequence="1001" Title="Open Google">

   3:     <UrlAction Url="javascript:google_OpenModalDialog();" />

   4: </CustomAction>

Thanks to Jan and Chankaradeep for their part in my research.

CSS refreshment

Let me first introduce those who are not familiar with CSS to some basic selection rules …

• htmltag : apply style to all elements of a specific type (or htmltag)  (styling via html element)
• #someid : apply style to all elements with an id attribute like someid (styling via html attribute id)
• .someclass : apply style to all elements with a class attribute containing someclass (styling via html attribute class)

and some more advanced rules …

• td.someclass : apply style to all td elements with a class attribute containing someclass
• .someclass td : apply style to all td elements which are siblings from a html element with a class attribute containing someclass
• table.someclass td : apply style to all td elements which are siblings from a table element with a class attribute containing someclass

and finally some selectors where we filter an the attribute values …

• [attribute] : apply style whenever an element has this attribute, no matter what it’s value is
• [attribute=somevalue] : apply style whenever an element has this attribute with the specified value
• [attribute~=somevalue] : apply style whenever an element has this attribute and contains somevalue (the values have to be space separated words)
• [attribute|=somevalue] : apply style whenever an element has this attribute and somevalue is in it (the values have to be hyphen separated words)
• [attribute^=somevalue] : apply style whenever an element has this attribute and his value starts with somevalue
• [attribute$=somevalue] : apply style whenever an element has this attribute and his value ends with somevalue

You can find more CSS tutorials and samples on the internet.

Styling the WebPartZones

We use the out-of-the-box pagelayout ‘Blank Web Part Page’ to style the Web Part zones. If you look at the source of the page, you will notice that every zone starts with a table cell (td) and has an id and name, ‘_invisibleIfEmpty’. A simple style to draw a border around every zone is:

td[id=_invisibleIfEmpty] { border: solid 1px #000000; } or td[name=_invisibleIfEmpty] { border: solid 1px #000000; }

If we want to style only the webparts in a specific zone, we will have to alter the pagelayout. Go the the page layout library, download a copy, make some changes and upload it again. Or better, create your own page layouts and page content types and publish these to the site collection. Let’s add a class, borders, in the ‘Blank Web Part Page’ page layout to the webpart zones ‘Center Left’, ‘Center’ and ‘Center Right’ by adding a class attribute with the value borders to the td’s. Change the CSS definitions to:

td.borders[id=_invisibleIfEmpty] { border: solid 1px #000000; } or td.borders[name=_invisibleIfEmpty] { border: solid 1px #000000; }

Styling the WebParts

Those who take a closer look at the source code of a page with some webparts on it, will notice that the parent table of every web part has an attribute TOPLEVEL. To style a border for example around every webpart (including the title and content) you can start with a very simple CSS definition:

table[TOPLEVEL] { border: solid 1px #000000; }

To address specific webparts, for example in a zone, you can change the page layout like described before and add the class before the definition:

.borders table[TOPLEVEL] { border: solid 1px #000000; }

The table with the TOPLEVEL attribute contains two rows, one for the title and one for the content of the webpart. The title resp. content have a specific class ms-WPHeader resp. ms-WPBody. These classes can be used to style the title and content:

.ms-WPHeader { background-color: yellow; } resp. ms-WPBody { background-color: yellow; }

If you dive deeper, you will notice that the title row has a td with a title attribute. This way you can even style individual webparts (as long as the title stays the same) with the following CSS definition:

.ms-WPHeader[title="sometitle"] { background-color: blue; }

There is even a class for the h3 html element specific for webparts, nl ms-WPTitle.

Conclusion

Styling all zones or webparts is rather simple and costs a minimal of time. Once you get some specific requirements for webparts or zones, you have to dive into the page layouts and webparts. Styling custom build webparts gives you more flexibility, but you will often notice that they want to use OOTB and Custom webparts together and style them all the same way. This can be accomplished with some more work, but is not undoable.

- If you get a HttpContext.Current.Session is nothing or HttpContext.Current.Session is null.
- If a page gives you “Session state can only be used when enableSessionState is set to true, either in a configuration file or in the Page directive” and you’re absolutely sure you did this and other things Microsoft recommends to use Session State in SharePoint.
- If you have enabled Session State through SharePoint Central Administration.
- When you try to set the EnableSessionState attribute on the Page directive of your Application Page and the following error comes back: “The enablesessionstate attribute on the page directive is not allowed in this page.”.

Then just use the ‘Reset to site definition‘ in your Site Settings of your Site Collection. Simple isn’t? What is it doing, well send an email to Microsoft, because I can’t tell you, but it fixed the problem for me.

Correction previous post: The override of the FieldRenderingControl can be skipped as well. The standard rendering of a SPFieldUrl is sufficient.

In this post, I will describe how to make your self a custom field editor. You probably saw that SharePoint renders the controls itself if you edit the list column. Although it is working, to me it doesn’t look nice. It’s not that much work to make your own sections and display the properties of the field when editing.

First of all, you have to set the Hidden attribute of the properties to TRUE in the field type definition property schema. Next, you have to add a user control to the CONTROLTEMPLATES folder, in which you will add the custom sections. Refer to a class file which inherits from the IFieldEditor, register the necessary tag prefixes and add two input form sections like below.

<wssuc:InputFormSection runat=”server” id=”ifsImages” Title=”Image settings” Description=”Set the header image and item image.”>
  <template_inputformcontrols>
    <wssuc:InputFormControl runat=”server” LabelText=”Header image:”>
      <Template_Control>
        <asp:TextBox ID=”tbHeaderImage” runat=”server” Width=”280″></asp:TextBox>
      </Template_Control>
    </wssuc:InputFormControl>
    <wssuc:InputFormControl runat=”server” LabelText=”Item image:”>
      <Template_Control>
        <asp:TextBox ID=”tbItemImage” runat=”server” Width=”280″></asp:TextBox>
      </Template_Control>
    </wssuc:InputFormControl>
  </template_inputformcontrols>
</wssuc:InputFormSection>
<wssuc:InputFormSection runat=”server” id=”ifsLink” Title=”Link settings” Description=”Specify if you want to see the description and want to open the link in a new window.”>
  <template_inputformcontrols>
    <wssuc:InputFormControl runat=”server” LabelText=”Show description:”>
      <Template_Control>
        <asp:CheckBox ID=”cbShowDescription” runat=”server” />
      </Template_Control>
    </wssuc:InputFormControl>
    <wssuc:InputFormControl runat=”server” LabelText=”Open link in new window:”>
      <Template_Control>
        <asp:CheckBox ID=”cbOpenLinkInNewWindow” runat=”server” />
      </Template_Control>
    </wssuc:InputFormControl>
  </template_inputformcontrols>
</wssuc:InputFormSection>

In the CustomFieldEditor class, you define the web controls and for each web control a private property to store the selected value. Override the CreateChildControls and assign the selected values to the web controls.

tbHeaderImage.Text = selectedHeaderImage
tbItemImage.Text = selectedItemImage
cbShowDescription.Checked = selectedShowDescription
cbOpenLinkInNewWindow.Checked = selectedOpenLinkInNewWindow

Implement the DisplayAsNewSection, InitializeWithField and OnSaveChange methods. The first method just returns true, while in the second, you will map the field properties to the field editor properties.

Dim iwuf As ImageWithUrlField = CType(field, ImageWithUrlField)
selectedHeaderImage = iwuf.HeaderImage
selectedItemImage = iwuf.ItemImage
selectedShowDescription = iwuf.ShowDescription
selectedOpenLinkInNewWindow = iwuf.OpenLinkInNewWindow

In the OnSaveChange method, we have to set the selected variables, but this time with the values coming from the web controls and additionally update the values of the field. Get a reference to the field and update or set (first time) the properties.

selectedHeaderImage = tbHeaderImage.Text
selectedItemImage = tbItemImage.Text
selectedShowDescription = cbShowDescription.Checked
selectedOpenLinkInNewWindow = cbOpenLinkInNewWindow.Checked

Dim iwuf As ImageWithUrlField = CType(field, ImageWithUrlField)
If isNewField Then
  iwuf.UpdateHeaderImage(selectedHeaderImage)
  iwuf.UpdateItemImage(selectedItemImage)
  iwuf.UpdateShowDescription(selectedShowDescription)
  iwuf.UpdateOpenLinkInNewWindow(selectedOpenLinkInNewWindow)
Else
  iwuf.HeaderImage = selectedHeaderImage
  iwuf.ItemImage = selectedItemImage
  iwuf.ShowDescription = selectedShowDescription
  iwuf.OpenLinkInNewWindow = selectedOpenLinkInNewWindow
End If

Finally, we have to make some small adjustments to the field class. For each field property we have to add a dictionary with an integer and string and a private property. We also define an Update method for each property. Below it’s shown for the HeaderImage, the other are similar. For the context id we get the hashcode of the current context.

Private Shared _headerImageDictionary As Dictionary(Of Integer, String) = _
  New Dictionary(Of Integer, String)
Private _headerImage As String
Public Sub UpdateHeaderImage(ByVal value As String)
  _headerImageDictionary(ContextId) = value
End Sub
Public Property HeaderImage() As String
  Get
    Initialize()
    If _headerImageDictionary.ContainsKey(ContextId) Then
      _headerImage = _headerImageDictionary(ContextId)
    End If
    Return _headerImage
  End Get
  Set(ByVal value As String)
    IsInitialized = True
    _headerImage = value
  End Set
End Property

In the OnAdded method, below the base call, we add a new method call, Update(). This method and the Initialize method (from the properties) is needed to Set and Get the Custom Properties.

Public Overrides Sub Update()
  SetCustomProperty(“HeaderImage”, HeaderImage)
  SetCustomProperty(“ItemImage”, ItemImage)
  SetCustomProperty(“ShowDescription”, ShowDescription.ToString())
  SetCustomProperty(“OpenLinkInNewWindow”, OpenLinkInNewWindow.ToString())

  MyBase.Update()

  If _headerImageDictionary.ContainsKey(ContextId) Then
    _headerImageDictionary.Remove(ContextId)
  End If
  If _itemImageDictionary.ContainsKey(ContextId) Then
    _itemImageDictionary.Remove(ContextId)
  End If
  If _showDescriptionDictionary.ContainsKey(ContextId) Then
    _showDescriptionDictionary.Remove(ContextId)
  End If
  If _openLinkInNewWindowDictionary.ContainsKey(ContextId) Then
    _openLinkInNewWindowDictionary.Remove(ContextId)
  End If
End Sub

Private Sub Initialize()
  If IsInitialized Then
    Exit Sub
  End If

  If GetCustomProperty(“HeaderImage”) IsNot Nothing Then
    HeaderImage = GetCustomProperty(“HeaderImage”).ToString()
  End If
  If GetCustomProperty(“ItemImage”) IsNot Nothing Then
    ItemImage = GetCustomProperty(“ItemImage”).ToString()
  End If
  If GetCustomProperty(“ShowDescription”) IsNot Nothing Then
    ShowDescription = CType(GetCustomProperty(“ShowDescription”), Boolean)
  End If
  If GetCustomProperty(“OpenLinkInNewWindow”) IsNot Nothing Then
    OpenLinkInNewWindow = CType(GetCustomProperty(“OpenLinkInNewWindow”), Boolean)
  End If

  IsInitialized = True
End Sub

Rebuild your project and upgrade the solution.

$(“.item[id*='sometext']“);

First of all, jQuery doesn’t has an Attribute filter in the selectors to select the opposite. They do have an inverse for the attribute filter ‘attr=value’, but this won’t work for ‘attr*=value’. So you have to work with the :not basic filter. The documentation and examples there say :not(selector), so you would think that the following would work.

$(“:not(.item[id*='sometext'])”);

But I won’t, it just selects about anything. The only correct way is to move the :not just before the attribute filter like this.

$(“.item:not([id*='sometext'])”);

Seems simple once you know

First we defined the field type and called it an ‘Imagelink’. We also associated a field type class which we will define later.

<Field Name="TypeName">Imagelink</Field>
<Field Name="TypeDisplayName">Image with Url</Field>
<Field Name="TypeShortDescription">Imagelink</Field>
<Field Name="ParentType">URL</Field>
<Field Name="UserCreatable">TRUE</Field>
<Field Name="ShowInListCreate">TRUE</Field>
<Field Name="ShowInSurveyCreate">FALSE</Field>
<Field Name="ShowInDocumentLibraryCreate">TRUE</Field>
<Field Name="ShowInColumnTemplateCreate">TRUE</Field>
<Field Name="FieldTypeClass">Imagelink.Imagelink, Imagelink, …</Field>

Next we had to define some custom properties to store the image links and additional requirements (default values were set to images inside SharePoint out-of-the-box).

<PropertySchema>
  <Fields>
    <Field Name="HeaderImage" DisplayName="Header Image"
           Hidden="FALSE" Type="Text">
      <Default>/_layouts/images/linktosite.gif</Default>
    </Field>
    <Field Name="ItemImage" DisplayName="Item Image"
           Hidden="FALSE" Type="Text">
      <Default>/_layouts/images/linktosite.gif</Default>
    </Field>
    <Field Name="ShowDescription" DisplayName="Show description"
           Hidden="FALSE" Type="Boolean"></Field>
    <Field Name="OpenLinkInNewWindow" DisplayName="Open link in new window"
           Hidden="FALSE" Type="Boolean"></Field>
  </Fields>
</PropertySchema>

To finish the ‘fldTypes_…’ xml file, we must implement the HeaderPattern and DisplayPattern.

The header pattern is pretty straight forward. If the HeaderImage custom property is not defined or empty, use the textual name of the field. In the other case, we build a HTML image tag and set the source and title attribute of this field.

<RenderPattern Name="HeaderPattern" DisplayName="HeaderPattern">
  <Switch>
    <Expr><Property Select="HeaderImage" /></Expr>
    <Case Value="">
      <Property Select="DisplayName" HTMLEncode="TRUE" />
    </Case>
    <Default>
      <HTML><![CDATA[<img src="]]></HTML>
      <Property Select="HeaderImage" />
      <HTML><![CDATA[" title="]]></HTML>
      <Property Select="DisplayName" HTMLEncode="TRUE" />
      <HTML><![CDATA[" />]]></HTML>
    </Default>
  </Switch>
</RenderPattern>

The display pattern is a bit more complex, since we have to readout the values of several custom properties. There are multiple switch statements:

1.    Check the value of the field (line 3), if empty display nothing
       and exit, else continue
2.    If value of the custom property ‘ItemImage’ (line 7) is empty
2.1.    Open the HTML Hyperlink opening tag and set the href attribute
2.2.    Check the value of the custom property ‘OpenLinkInNewWindow’
         (line 13-15)
2.2.1.    If true, add an extra attribute target and set it to _blank
2.3.    Close the HTML Hyperlink opening tag
2.4.    Print the description
2.5.    Print the HTML Hyperlink closing tag
3.    If value of the custom property ‘ItemImage’ (line 7) is not empty
3.1.    If value of the custom property ‘ShowDescription’ (line 26-28)
         is true
3.1.1.    Open the HTML Hyperlink opening tag and set the href
           attribute
3.1.2.    Check the value of the custom property
           ‘OpenLinkInNewWindow’ (line 34-36)
3.1.2.1.    If true, add an extra attribute target and set it to
             _blank
3.1.3.    Close the HTML Hyperlink opening tag
3.1.4.    Print the HTML Image tag and set border, style, source and
           title attribute
3.1.5.    Print the HTML Hyperlink closing tag
3.1.6.    Open a second HTML Hyperlink opening tag and set the
           href attribute
3.1.7.    Check the value of the custom property
           ‘OpenLinkInNewWindow’ (line 50-52)
3.1.7.1.    If true, add an extra attribute target and set it to
             _blank
3.1.8.    Close the HTML Hyperlink opening tag
3.1.9.    Print the HTML Hyperlink closing tag
3.2.    If value of the custom property ‘ShowDescription’ (line 26-28)
         is false
3.2.1.    Open the HTML Hyperlink opening tag and set the href
           attribute
3.2.2.    Check the value of the custom property
           ‘OpenLinkInNewWindow’ (line 66-68)
3.2.2.1.    If true, add an extra attribute target and set it to
             _blank
3.2.3.    Close the HTML Hyperlink opening tag
3.2.4.    Print the HTML Image tag and set border, source and title
           attribute
3.2.5.    Print the HTML Hyperlink closing tag 

<RenderPattern Name="DisplayPattern" DisplayName="DisplayPattern">
  <Switch>
    <Expr><Column /></Expr>
    <Case Value=""></Case>
    <Default>
      <Switch>
        <Expr><Property Select="ItemImage" /></Expr>
        <Case Value="">
          <HTML><![CDATA[<a href="]]></HTML>
          <Column HTMLEncode="TRUE" />
          <HTML><![CDATA["]]></HTML>
          <Switch>
            <Expr>
              <Property Select="OpenLinkInNewWindow" />
            </Expr>
            <Case Value="True">
              <HTML><![CDATA[ target="_blank"]]></HTML>
            </Case>
          </Switch>
          <HTML><![CDATA[>]]></HTML>
          <Column2 HTMLEncode="TRUE" />
          <HTML><![CDATA[</a>]]></HTML>
        </Case>
        <Default>
          <Switch>
            <Expr>
              <Property Select="ShowDescription" />
            </Expr>
            <Case Value="True">
              <HTML><![CDATA[<a href="]]></HTML>
              <Column HTMLEncode="TRUE" />
              <HTML><![CDATA["]]></HTML>
              <Switch>
                <Expr>
                  <Property Select="OpenLinkInNewWindow" />
                </Expr>
                <Case Value="True">
                  <HTML><![CDATA[ target="_blank"]]></HTML>
                </Case>
              </Switch>
              <HTML><![CDATA[><img border="0" style="margin-right:5px;"
                     src="]]></HTML>
              <Property Select="ItemImage" />
              <HTML><![CDATA[" title="]]></HTML>
              <Column2 HTMLEncode="TRUE" />
              <HTML><![CDATA["></a>]]></HTML>
              <HTML><![CDATA[<a href="]]></HTML>
              <Column HTMLEncode="TRUE" />
              <HTML><![CDATA["]]></HTML>
              <Switch>
                <Expr>
                  <Property Select="OpenLinkInNewWindow" />
                </Expr>
                <Case Value="True">
                  <HTML><![CDATA[ target="_blank"]]></HTML>
                </Case>
              </Switch>
              <HTML><![CDATA[>]]></HTML>
              <Column2 HTMLEncode="TRUE" />
              <HTML><![CDATA[</a>]]></HTML>
            </Case>
            <Default>
              <HTML><![CDATA[<a href="]]></HTML>
              <Column HTMLEncode="TRUE" />
              <HTML><![CDATA["]]></HTML>
              <Switch>
                <Expr>
                  <Property Select="OpenLinkInNewWindow" />
                </Expr>
                <Case Value="True">
                  <HTML><![CDATA[ target="_blank"]]></HTML>
                </Case>
              </Switch>
              <HTML><![CDATA[><img border="0" src="]]></HTML>
              <Property Select="ItemImage" />
              <HTML><![CDATA[" title="]]></HTML>
              <Column2 HTMLEncode="TRUE" />
              <HTML><![CDATA["></a>]]></HTML>
            </Default>
          </Switch>
        </Default>
      </Switch>
    </Default>
  </Switch>
</RenderPattern>

Finally we have to implement the fieldtypeclass by overriding the SPFieldUrl class. Define a private Boolean IsInitialized and set it false. The constructors are straight forward, as is the FieldRenderingControl. For the GetFieldValueAsHtml, you have to return the Url of the SPFieldUrlValue. In the OnAdded and OnUpdated method, check the IsInitialized Boolean and if not true, call the following method.

Private Sub ConfigureSchemaXml()
  IsInitialized = Not IsInitialized

  Dim HeaderImageValue As String = _
    MyBase.GetCustomProperty("HeaderImage")
  Dim ItemImageValue As String = _
    MyBase.GetCustomProperty("ItemImage")
  Dim ShowDescriptionValue As Boolean = _
    MyBase.GetCustomProperty("ShowDescription")
  Dim OpenLinkInNewWindowValue As Boolean = _
    MyBase.GetCustomProperty("OpenLinkInNewWindow")
  Dim doc As XmlDocument = New XmlDocument()

  doc.LoadXml(MyBase.SchemaXml)

  If (doc.FirstChild.Attributes("HeaderImage") Is Nothing) Then
    Dim xmlAttrib As XmlAttribute = doc.CreateAttribute("HeaderImage")
    xmlAttrib.Value = HeaderImageValue
    doc.FirstChild.Attributes.Append(xmlAttrib)
  Else
    doc.FirstChild.Attributes("HeaderImage").Value = HeaderImageValue
  End If
  If (doc.FirstChild.Attributes("ItemImage") Is Nothing) Then
    Dim xmlAttrib As XmlAttribute = doc.CreateAttribute("ItemImage")
    xmlAttrib.Value = ItemImageValue
    doc.FirstChild.Attributes.Append(xmlAttrib)
  Else
    doc.FirstChild.Attributes("ItemImage").Value = ItemImageValue
  End If
  If (doc.FirstChild.Attributes("ShowDescription") Is Nothing) Then
    Dim xmlAttrib As XmlAttribute = doc.CreateAttribute("ShowDescription")
    xmlAttrib.Value = ShowDescriptionValue
    doc.FirstChild.Attributes.Append(xmlAttrib)
  Else
    doc.FirstChild.Attributes("ShowDescription").Value = _
        ShowDescriptionValue
  End If
  If (doc.FirstChild.Attributes("OpenLinkInNewWindow") Is Nothing) Then
    Dim xmlAttrib As XmlAttribute = _
    doc.CreateAttribute("OpenLinkInNewWindow")
    xmlAttrib.Value = OpenLinkInNewWindowValue
    doc.FirstChild.Attributes.Append(xmlAttrib)
  Else
    doc.FirstChild.Attributes("OpenLinkInNewWindow").Value = _
        OpenLinkInNewWindowValue
  End If

  MyBase.SchemaXml = doc.OuterXml
End Sub

If everything went well, you should see a new fieldtype, but it cannot be used from the userinterface. You will still get some errors. However if you use it from code, it will work already. In Part 2, I will discuss how to alter this one to use it as a real fieldtype via the userinterface.

The case (ripped to the bottom) was very simple. I had to create a new Site Collection, add a group to this new Site Collection and update some properties of this new group. Simple isn’t it? Let me paste the code I wrote for this and probably everyone sees the problem immediately. Only thing I have as input was an url to a Site Collection, an url, a title and an owner for the new Site Collection and a name for the new Group.

Dim site As SPSite = New SPSite(siteUrl)
Dim webApp As SPWebApplication = site.WebApplication

Dim newSite As SPSite = webApp.Sites.Add(newSiteUrl, newSiteTitle, Nothing, 1033, newSiteOwner, Nothing, Nothing)
Dim newWeb As SPWeb = newSite.RootWeb()

newWeb.SiteGroups.Add(newGroupName, site.Owner, Nothing, Nothing)
Dim newGroup As SPGroup = newWeb.SiteGroups(newGroupName)

You see it? Let’s hope you don’t, otherwise I feel really stupid On the last line, you get a nice exception, Group cannot be found. Unless, and here is the fun part, your site.Owner is the same account as who is running your Web Application (in other words the account running the Application Pool for your Web Site in IIS).

So you have a workaround and a real problem to tackle. If you know what, it is simple. Don’t use SPUser objects from other Site Collections to do things! You see the problem now? For those who don’t, replace site.Owner (an SPUser object from another Site Collection) with newSite.Owner and everything is solved. Stupid I looked over this and didn’t realised this could be a potential problem, but lesson learned as they say.

So, after some research on the internet and the MSDN library, I found out that a SPFieldUserValueCollection contains an Exists method, to which you have to pass a delegate to a method. This delegate method will accept a Predicate(Of T) on a List(T). So in our case the delegate method had to accept a SPFieldUserValue. In return it will give a boolean value defining if the user is contained in the People or Group field.

A People or Group field can contain SharePoint Groups, Domain Users, Domain Groups and/or Distribution Groups. Below you can find an implementation for the first three types of values. The method can be used for a single value and multiple value People or Group Field. As soon as it returns true, it will skip checking other values in the multiple value form. You can replace the web object with SPContext.Current.Web offcourse and keep in mind that you have to implement the DomainGroupContainsCurrentUser method. Implementations of this using LDAP can be found at the internet.

Private Function CurrentUser(ByVal fuv As SPFieldUserValue) As Boolean
     If fuv.User IsNot Nothing AndAlso Not fuv.User.IsDomainGroup Then
         Return (fuv.User.ID = web.CurrentUser.ID)
     ElseIf fuv.User IsNot Nothing AndAlso fuv.User.IsDomainGroup Then
         Return DomainGroupContainsCurrentUser(fuv.User.Name)
     ElseIf web.SiteGroups.GetByID(fuv.LookupId).ContainsCurrentUser() Then
         Return True
     Else
         Return False
     End If
End Function

Calling this method is pretty simple. Suppose you have a SPFieldUserValueCollection, fuvc, then you just enter fuvc.Exists(AddressOf CurrentUser) in VB.NET. This approach can be used for every SP…Collection because they all derive from List(T).