Rendering a single component presentation in DD4T

Question

I have a page with several component presentations using the component template 'Promotion'. In my page view '_Page.cshtml' I wish to write out all component presentations using this template and for every second occurance write some HTML just after i've written the component presentation.

I would use the following code to write out all presentations of a certain template:

@Html.RenderComponentPresentationsByView("Promotion")

I figured I could replace this code with the following (where my Model = IPage):

@foreach (ComponentPresentation cp in Model.ComponentPresentations)
{
    if (cp.ComponentTemplate.Title == "Promotion")
    {                                   
        //Logic here to render my specific CP through HTML.RenderComponentPresentations() or something else?
    }
}

I need to replace my comment with code to achieve the same result as RenderComponentPresentationsByView but for a single component presentation.

any Ideas on how to achieve this?

Thanks in advance

Answer 1

Calling

Html.Partial("Promotion", cp);

from within your loop should do the job.

Answer 2

I achieved this by calling the method using RenderAction from my view:

Html.RenderAction("ComponentPresentationByObject", "MyComponent", cp);

Note: This was only possible once I'd added the following method to the abstract class DD4T.Mvc.Controllers.TridionControllerBase.

public virtual ActionResult ComponentPresentationByObject(ComponentPresentation cp)
{
    try
    {
        return GetView(cp);
    }
    catch (ConfigurationException e)
    {
        return View("Configuration exception: " + e.Message);
    }
}

I inherit the abstract class TridionControllerBase in a class local to my project, MyComponent.

Strangely enough it there is a commented method in the default DD4T implementation which would seem to (nearly) provide this. I initially tried uncommenting the provided DD4T method 'TridionControllerBase.ComponentPresentation(string componentPresentationId)' but this gave me two errors (1) You must use a unique name for the action result as overloading is not permitted on Controller classes. (2) An error stating that it could not implement an interface.

Therefore I made a unique method name then changed the parameter from IComponentPresentation to ComponentPresentation.