A DD4T.net Implementation - Rendering One Component Presentation Only

DD4T 1.3 comes with a few Html extension methods that allow us to render Component Presentation inside a Page Razor view using different ways of filtering through the list of ComponentPresentations on the IPage object:

• RenderComponentPresentations() -- renders all ComponentPresentations on the page;
• RenderComponentPresentationsBySchema() -- renders only ComponentPresentations whose Component is based on a given Schema title or TcmUri;
• RenderComponentPresetnationsByView() -- renders only ComponentPresentations whose ComponentTemplate uses a given view name or has a given TcmUri;

There is however, no helper method that allows the rendering of just a simple plain ComponentPresentation, yet sometimes that is exactly what I would need.

Below is one such Html extension method that calls the rendering of only the given ComponentPresentation object:

public static MvcHtmlString RenderComponentPresentation(this HtmlHelper htmlHelper,
    IComponentPresentation cp)
{
    if (!string.IsNullOrEmpty(cp.RenderedContent))
    {
        return new MvcHtmlString(cp.RenderedContent);
    }
    cp.Page = PageHelper.GetPage(htmlHelper);

    IFieldSet metaFields = cp.ComponentTemplate.MetadataFields;
    string controller = metaFields.StringValue("controller");
    if (string.IsNullOrEmpty(controller))
    {
        controller = ConfigurationHelper.ComponentPresentationController;
    }

    string action = metaFields.StringValue("action");
    if (string.IsNullOrEmpty(action))
    {
        action = ConfigurationHelper.ComponentPresentationAction;
    }

    return ChildActionExtensions.Action(htmlHelper, action, controller,
        new { componentPresentation = (ComponentPresentation)cp });
}

Note two things about the code above:

• it uses the IFieldSetExtension methods presented in post IFieldSet Extension Methods, which allow us to read values from IFieldSet collections easily;
• it uses PageHelper.GetPage method presented in post Get the Page Model from Component Presentation, which allows us to read the Page model from the current ViewContext;

Call this helper method using code similar to the sample below:

    @foreach (var cp in Model.ComponentPresentations)
    {
        <div class="content">
            @Html.RenderComponentPresentation(cp)
        </div>
    }