You can extend the Office Communicator 2007 R2 user interface by adding pages of Web-based content to the Office Communicator window. The pages appear in a pane just below the Contact List, and the user switches between pages by clicking tabs at the bottom of the pane. Custom tabs are particularly powerful because they enable Office Communicator to pass the URI of the current user to the tab defined in the Office Communicator window.

In Communicator 2007 R2, you can now also add tabs to the contact card. The tabs appear at the bottom of the contact card, and clicking a tab opens a browser window with the defined page. The URI of the contact displayed in the contact card can be passed to the page defined in the custom tab.

The process for displaying a custom tab in Office Communicator consists of the following steps:

• Creating the content that you want to load in the custom tab. Save the content to a location on your network that will be accessible to Communicator and any other clients that need to display custom tabs. Content can be a static Web page or a Web application that includes HTML, JavaScript, ActiveX controls, and pop-up windows.
  
• Creating and configuring the XML file that is used to configure custom tabs for Office Communicator. The format of this XML file has been modified to include a new <client> attribute, which specifies whether the custom tab should also appear in Communicator Web Access clients.
  
• Defining a registry entry in the \Software\Policies\Microsoft\Communicator registry hive that gives the location of the tab definition file.
  
• Creating a graphic in Portable Network Graphics (PNG) format for the tab. The graphic can be up to 16 pixels high by 16 pixels wide, or exactly 32 pixels high by 32 pixels wide. If you intend to display the graphic in Communicator Web Access, the graphic must be located on a secure (HTTPS) site. Otherwise, a security warning will appear when the graphic is displayed.
  

A registry string value, TabURL, contains a URL that points to the XML descriptor file. TabURL can be added to the following registry keys.

HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Microsoft\Communicator

HKEY_CURRENT_USER\Software\Policies\Microsoft\Communicator

The TabURL setting can be added to either section of the registry. However, settings in the HKEY_LOCAL_MACHINE\SOFTWARE section take precedence.

Office Communicator 2007 R2 uses an XML tab definition file to define the displayed tabs and the address of the each tab’s main page. The tab definition file has the following format:

<?xml version="1.0" ?>  
<tabdata> 
<tab> 
   <image>https://site/image.png</image>  
   <name>Tab title</name> 
   <tooltip>Tooltip text</tooltip>  
   <contenturl> http://site/content</contenturl>   
   <userid>true</userid>
   <contactid>true</contactid>
   <accessibility>inside</accessibility>
   <client>
      <communicatorWebAccess>true</communicatorWebAccess>
   </client>
 </tab> 
</tabdata>

XML elements in the Custom Tab Definition file

XML Element	Description	Required Element
!ELEMENT tabdata tab*	Contains 0 or more tab elements. The maximum number of tab elements is 32.	No
!ELEMENT tab (image, name, tooltip, contenturl, userid, contactid, accessibility, client)	Contains image, name, tooltip, contenturl, userid, contactid, and accessibility elements.	No
!ELEMENT image %URI	Provides a URL for the tab image icon. The image must be in PNG format.	No
!ELEMENT name (#PCDATA)	A friendly name for the XML node. This is not displayed in the user interface.	Yes
!ELEMENT tooltip (#PCDATA)	Displays the text of the tooltip when the mouse pauses over the tab.	No
!ELEMENT contenturl %URI	Provides the URI of the page to be displayed when the user selects the tab. The file must be located on the intranet, or on a secure or trusted site on the internet. The link must be in https:// format (recommended), or in http:// or file:/// format.	Yes
!ELEMENT userid (“true” | “false”)	Determines whether Communicator will pass the user’s Session Initiation Protocol (SIP) account ID information to the tab URL. The default value is “false.”	No
!ELEMENT contactid (“true” | “false”)	Determines whether the tab appears in the contact card. Tabs defined without contactid or with contactid=false will appear only in the Communicator window. Tabs defined with contactid=true will appear in the contact card, and Communicator will pass the selected contact to the defined page. The default value is “false.”	No
!ELEMENT accessibility (“inside” | “outside” | “both”)	Determines whether the URL must be displayed when the user logs in from inside the enterprise, outside the enterprise, or both. This is provided so that Communicator 2007 R2 does not attempt to display intranet pages when the user logs in from outside the company, resulting in a “page not found” error.	No
!ELEMENT client (communicatorWebAccess)	Specifies the clients that should display the tab, in addition to Office Communicator.	No
!ELEMENT communicatorWebAccess (“true” | “false”)	Specifies that Communicator Web Access clients should display the tab.	No

Note:

The tab icon must be in Portable Network Graphics (PNG) format. If the PNG file cannot be found or is not in the correct format, Communicator displays a default icon. The HTML file containing the tab content must be in a trusted location on the network. The XML and PNG files can be stored in the same location as the HTML file, or on a network server or local machine. For example: file:///\\contonso-it\oc\tabs.xml file:///c:/myTab/tabs.xml

Tab definition file example

The following example shows a tab definition file with two tabs.

<?xml version="1.0" ?>  
<tabdata> 
<tab> 
   <image>https://site/news.png</image>  
   <name> News</name> 
   <tooltip>Technology News</tooltip>  
   <contenturl>http://www.contoso.com/news</contenturl>
   <userid>true</userid>
   <contactid>true</contactid>
   <accessibility>inside</accessibility>
   <client>
      <communicatorWebAccess>true</communicatorWebAccess>
   </client>
 </tab> 
<tab> 
   <image>https://site/sports.png</image>  
   <name>Sports</name> 
   <tooltip>Sports News</tooltip>  
   <contenturl>http://www.contoso.com/sports</contenturl>
   <userid>true</userid>
   <contactid>true</contactid>
   <accessibility>inside</accessibility>
   <client>
      <communicatorWebAccess>true</communicatorWebAccess>
   </client>
 </tab> 
</tabdata>

Note:
The XML file can be used to configure up to 32 tabs on the client. However, exercise some caution, because a long list of tabs on a client computer that uses a low-resolution screen can become difficult for the user to manage.