Using CustomAction to modify system pages

In the last post, I covered 2 examples of how to safely modify functionality in 'system' areas of SharePoint, such as Central Admin and the Site Settings area. The first example was a tweaked Recycle Bin (which listed only items deleted by the current user), and the second was a custom 'Create Site Collection' admin page. In both cases, the technique was to copy the original page which shipped with SharePoint, make the customization to the copy, and then redirect the link in SharePoint to use our new page. The customization is then fairly transparent to users - depending on your implementation, they could simply be clicking the same link in the same place in SharePoint, yet going to somewhere different which is offering your modified functionality.

This last part (of redirecting the link in SharePoint) is accomplished via a Feature which makes use of the CustomAction element. However, this idea of changing an existing link somewhere in SharePoint is not necessarily the type of customization you might regularly make. So it's useful to know the CustomAction element can also be used to add a link somewhere in SharePoint. This opens up many opportunities for customization, and this post aims to detail some of the options.

The CustomAction element is used like this:

<CustomAction Id="MyDeletedItems"

              GroupId="SiteCollectionAdmin"

              Location="Microsoft.SharePoint.SiteSettings"

              Sequence="10"

              Title="My recycle bin items"

              Rights="ManageWeb,BrowseUserInfo">

  <UrlAction Url="_layouts/custom/MyRecycleBinItems.aspx" />

</CustomAction>

I covered most of the values in details in the previous post, but what I want to focus on here is the Location attribute - this essentially specifies where in SharePoint your link will be added to. Some of the common potential values are:

• Microsoft.SharePoint.SiteSettings (as in the example XML above)
  
• Microsoft.SharePoint.Administration.Operations
  
• Microsoft.SharePoint.Administration.ApplicationManagement

If you've worked with SharePoint for a while you can probably work out where these values refer to - the first is the Site Settings area, whilst the last two are the 'Operations' and 'Application Management' pages in the Central Admin area respectively. When using a CustomAction to add links in these areas, you can also specify the group your link should appear in. This value refers to an existing 'category' of links within the Location, e.g. the locations listed above. Note that new groups can be created by using a CustomActionGroup element, but the GroupID value of a CustomAction must always specify a group which exists already. The following groups exist by default in the SiteSettings area:

• UsersAndPermissions
  
• Customization
  
• QuickLaunch
  
• Galleries
  
• SiteAdministration
  
• SiteCollectionAdmin

These correspond to the columns in the Site Settings area as shown below:

In the Central Admin pages, examples for the 'Operations' page are:

• Topology
  
• GlobalConfiguration
  
• Security
  
• BackupRestore
  
• LoggingAndReporting
  
• DataConfiguration
  
• Upgrade

And for the 'Application Management' page:

• WebApplicationConfiguration
  
• SiteManagement
  
• ApplicationSecurity
  
• ExternalService
  
• WorkflowManagement

By examining these pages, it's fairly simple to work out where the values refer to.

I mentioned earlier that new groups of links can be created using the CustomActionGroup element. An example of this would be:

<CustomActionGroup

    Id="CustomSiteSettingsGroup"

    Location="Microsoft.SharePoint.SiteSettings"

    Title="New custom group"

    Sequence="100"

    Description="My description" />

This will then create a new group of links on the page with your custom title - SharePoint will take care of the rendering such that your new group will wrap onto another row of groups. Of course if this isn't what you want you'll probably have an interesting time customizing this.

Using CustomAction elsewhere

So having covered how to add links into the admin areas, I'll wrap up by listing some other valid values for the 'Location' attribute. This hopefully illustrates some of the options you have for customizing SharePoint in this way:

• 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 - the screen used to specify what you want to create on your site)
  
• Microsoft.SharePoint.ListEdit (the screen used to edit the properties of a list item)
  
• EditControlBlock (image below)

I've put the last few in bold and added a description as I think they're particularly interesting. Of course, if you have other customizations in mind one or two of the others might have caught your eye! In particular being able to add custom actions to the EditControlBlock is interesting:

Here, a special attribute called 'RegistrationType' can be added to the CustomAction element, allowing you to control exactly the circumstances where your action should appear. Valid options include 'List', 'ContentType', 'FileType' and 'ProgId'. Vince (aka TheKid) has some good examples of this over on his blog.

Hopefully this has given you some ideas on how you can add or amend the SharePoint UI in this way. Happy customizing!