EPiServer 5 R2 and Link Collection property

With EPiServer 5 R2 new property type was released -- Link Collection. It looks like a EPiServer's version of very popular Mulitipage property. In this post I would like to show you exactly how it can be used and also what are the pros and cons.

After adding a property of this type to a page you will see in edit mode this:


And with a few links added property looks like this:


This is first significant change comparing to old Multipage property (MP) -- list of all links is visible on the page. With old MP it was necessary to click on the button to get a popup with a list of links. That is a good change!

What is missing here for me is a ability to test links. Text which you can see for the first item on the list is not necessary a page name (it might be a clickable text) so it's impossible to figure out from this view what page is referenced.

Funny thing is that title for this link has a following form:

It is very useful isn't it? ;) I think the simplest solution would be to make link text clickable.

After clicking on 'Add Link' or 'Edit' button you will get old popup:


There are no surprises here, it's an old well-know dialog.

Lets check now how to deal with Link collection in a code. It's quite common to use Repeater to display links:

   1:  <asp:Repeater ID="rptRelatedLinks" runat="server">

   2:      <HeaderTemplate><dl></HeaderTemplate>

   3:      <ItemTemplate><dt><asp:HyperLink runat="server" ID="hplMainLink" /></dt></ItemTemplate>

   4:      <FooterTemplate></dl></FooterTemplate>

   5:  </asp:Repeater>

And here is a code to get links from the CurrentPage:

   1:  PropertyLinkCollection links = (PropertyLinkCollection) CurrentPage.Property["RelatedLinks"];

   2:  rptRelatedLinks.DataSource = links;

   3:  rptRelatedLinks.DataBind();

And a method populating the Repeater:

   1:  void rptRelatedLinks_ItemDataBound(object sender, RepeaterItemEventArgs e)

   2:  {

   3:      if (e.Item.ItemType == ListItemType.Item || e.Item.ItemType == ListItemType.AlternatingItem)

   4:      {

   5:          LinkItem linkItem = (LinkItem) e.Item.DataItem;

   6:          HyperLink link = (HyperLink) e.Item.FindControl("hplMainLink");

   7:  

   8:          // mapped link has a form like:

   9:          // <a href="/Templates/Public/Pages/Page.aspx?id=16&epslanguage=en" target="_blank" 

  10:          //       title="this is link title">Information about the meeting</a>

  11:          string mappedLink = linkItem.ToMappedLink();

  12:          

  13:          // permanent link form:

  14:          // <a href="~/link/bb6aa3227f8f467bbe1a42154cb56ba5.aspx" target="_blank" 

  15:          //           title="this is link title">Information about the meeting</a>

  16:          string permanentLink = linkItem.ToPermanentLink();

  17:  

  18:          // because Href property will return permanent link like 

  19:          // ~/link/bb6aa3227f8f467bbe1a42154cb56ba5.aspx

  20:          //

  21:          // it's necessary to use PermanentLinkMapStore.ToMapped(url) to covert it to normal form

  22:          // result is required to determine if conversion was successful

  23:          // it will fail for mails (mailto:test@test.com), documents and external links

  24:          UrlBuilder url = new UrlBuilder(linkItem.Href);

  25:          bool result = PermanentLinkMapStore.ToMapped(url);

  26:  

  27:          link.NavigateUrl = result ? url.ToString() : linkItem.Href;

  28:          link.Text = linkItem.Text;

  29:          link.ToolTip = linkItem.Title;

  30:          link.Target = linkItem.Target;

  31:      }

  32:  }

The basic problem is that Href property returns permanent link, therefore it's necessary to use PermanentLinkMapStore class to convert the links. ToMappedLink() method returns a full "a" tag, which might be convenient in some cases. Take a look on all properties again:

My overall impression is positive, new property Link collection is easy to use but for sure there are things which could be improved like ability to test a link or ability to define page root to look for pages to include. It's a hassle to always start from the very top!

I wonder now if there is still a reason to use old Multipage property, what do you think?

Related posts:

• MultipageProperty -- don't use SelectedPages property!
• Problems with EPiServer 5 R2 and MS Vista
• Ultimate diagnostic tool for EPiServer
• Edit Page - Shortcut/External link tab