Issue trying to use Datasource Template in Sitecore sublayout; getting empty Sublayout.Datasource

Question

We've been trying to "componentize" our Sitecore solution as we move forward, in prep for transitioning to Page Editor usage (Woot! Finally!), but we're still practically working primarily with Page templates that may be inheritance-based composites of page specific fields, plus 1:many of these componentized templates. An example of how this looks in our solution is below -- Banner Feature Carousel and Featured Cartoon are some of these new components we're creating:

In the interest of trying to move away from using Sitecore.Context.Item (as I was recently reminded by this post) I've started filling in the Datasource template field on the sublayouts for the new components, and it seems like I've got the appropriate connections made between presentation details, the Sitecore sublayout and the .NET code file (as far as I can tell; again, we're newer to working this way).

I've also tried setting up a base class for these components as per this post by Nick Allen, but here's where I'm running into a problem: When I execute my code, this base class is finding the component Sublayout appropriately (the whole "this.Parent as Sublayout" thing) but, when I go to interrogate the Sublayout.Datasource property, it's an empty string. Here's my code (so far) for this base class:

public class ComponentBase : System.Web.UI.UserControl
{
    private Sublayout Sublayout { get { return Parent as Sublayout; } }

    public Item DataSourceItem 
    { 
        get 
        { 
            return Sublayout != null && !String.IsNullOrEmpty(Sublayout.DataSource) ? 
            Sitecore.Context.Database.GetItem(Sublayout.DataSource) : Sitecore.Context.Item; 
        } 
    }
}

I'm apparently missing some interplay between the Datasource Template field in the Sitecore sublayout, and how that actually translates to a datasource. Is it because these component templates are being used to compose Page templates? I was thinking that the datasource would just ultimately resolve to the Page template on which the component in question was currently being used, but perhaps that's my misunderstanding.

If anyone could give me any hints of things to check or point me to any resources I might use to get further, I'd appreciate it. I've done quite a bit of asking the Googs, myself, but am just not getting anything that's helping.

Thank you in advance, Sitecore friends!

Answer 1

It looks like you have configured the allowed templates for your sublayout in the steps you describe above. This basically tells Sitecore; 'allow user to select items based on these templates for this sublayout'. This alone does not set up the data source on items using the sublayout. You still need to go into the presentation details for any items using this sublayout, select the sublayout and then set its datasource property (within the content editor go to Presentation > Details > [Sublayout] > Data Source).

My answer to this question gives the source code needed to retrieve the datasource item and to iterate through the sitecore controls on your sublayout setting all of their Item propertys.

Here is the code:

public class SublayoutBase : UserControl
{
    private Item _dataSource;

    public Item DataSource
    {
        get
        {
            if (_dataSource == null)
            {
                if (Parent is Sublayout)
                {
                    _dataSource =
                        Sitecore.Context.Database.GetItem(((Sublayout)Parent).DataSource);
                }
                if (_dataSource == null)
                {
                    _dataSource = Sitecore.Context.Item;
                }
            }
            return _dataSource;
        }
    }

    protected override void OnLoad(EventArgs e)
    {
        foreach (Control c in Controls)
        {
            SetFieldRenderers(DataSource, c);
        }
        base.OnLoad(e);
    }

    private void SetFieldRenderers(Item item, Control control)
    {
        if (item != null)
        {
            var ctrl = control as Sitecore.Web.UI.WebControl;
            if (ctrl != null && !string.IsNullOrEmpty(ctrl.DataSource))
            {
                //don't set the source item if the DataSource has already been set. 
                return;
            }
            if (control is FieldRenderer)
            {
                var fr = (FieldRenderer)control;
                fr.Item = item;
            }
            else if (control is Image)
            {
                var img = (Image)control;
                img.Item = item;
            }
            else if (control is Link)
            {
                var link = (Link)control;
                link.Item = item;
            }
            else if (control is Text)
            {
                var text = (Text)control;
                text.Item = item;
            }
            else
            {
                foreach (Control childControl in control.Controls)
                {
                    SetFieldRenderers(item, childControl);
                }
            }
        }
    }
}