Skip to main content

A DD4T.net Implementation - Strong-Typed Model in Component Controller

In the previous post, I was mentioning that a Component controller can be reused in both cases when the Component Presentation is embedded on the Page, as well as when it is published as Dynamic Component Presentation (DCP). In this post I will elaborate this topic.

The Component controller consists of the following sample code:

    public class DeviceController : MyControllerBase
    {
        public ActionResult Index(int? publication, int? component, string view)
        {
            Device device;
            string viewName;
            ResolveModelAndView<Device>(publication, component, view, out device, out viewName);

            return View(viewName, device);
        }
    }

Two things to note here:
  • DeviceController is a specialization of MyControllerBase;
  • Method ResolveModelAndView is defined in a parent class and is in charge with figuring out both the strongly-typed model for the Component and the view name;

The method implementation, as defined in the MyControllerBase, is the following:

    public void ResolveModelAndView<T>(int? publication, int? component, string view, out T model, out string viewName) where T : ModelBase
    {
        model = GetModel<T>(publication, component, view);
        viewName = GetViewName(view);

        if (model == null || string.IsNullOrEmpty(viewName))
        {
            throw new HttpException(404, "Page Not Found");
        }
    }

The model is retrieved by method GetModel showcased below. The method behaves differently based on whether the Component Presentation is embedded on the Page or not.

If on the Page, calling GetComponentPresentation method defined in TridionControllerBase will give us the IComponentPresentation model; otherwise, we resort to using the ModelFactory to load the strongly-typed model.

One extra check is made on whether the Component Presentation is dynamic or not, this affecting the way we load its strong-typed model.

    public T GetModel<T>(int? publication, int? component, string view) where T : ModelBase
    {
        T model = null;
        string componentUri = null;
        IComponentPresentation componentPresentation = GetComponentPresentation();

        if (componentPresentation == null)
        {
            if (publication == null || component == null)
            {
                return null;
            }
            else
            {
                componentUri = string.Format("tcm:{0}-{1}", publication, component);
                model = ModelFactory.GetModel<T>(componentUri, view);
            }
        }
        else
        {
            if (componentPresentation.IsDynamic)
            {
                componentUri = componentPresentation.Component.Id;
                string templateUri = componentPresentation.ComponentTemplate.Id;
                model = ModelFactory.GetModel<T>(componentUri, templateUri);
            }
            else
            {
                model = ModelFactory.GetModel<T>(componentPresentation.Component);
            }
        }

        return model;
    }

The other method, GetViewName(string view) is quite straight forward, as it simply looks at the Component Template metadata to retrieve the view field.

    public string GetViewName(string view)
    {
        IComponentPresentation componentPresentation = GetComponentPresentation();
        return componentPresentation == null ? view : GetViewName(componentPresentation);
    }

    public string GetViewName(IComponentPresentation componentPresentation)
    {
        IComponentTemplate template = componentPresentation.ComponentTemplate;
        IFieldSet fields = template.MetadataFields;

        string viewName = fields.StringValue("view");
        if (string.IsNullOrEmpty(viewName))
        {
            viewName = template.Title;
        }

        return viewName;
    }

In case the Component Presentation is not present on the Page, there will be no Component Template model either, and as such, we need to provide our own view parameter (that we require as input parameter).



Comments

Popular posts from this blog

Running sp_updatestats on AWS RDS database

Part of the maintenance tasks that I perform on a MSSQL Content Manager database is to run stored procedure sp_updatestats . exec sp_updatestats However, that is not supported on an AWS RDS instance. The error message below indicates that only the sa  account can perform this: Msg 15247 , Level 16 , State 1 , Procedure sp_updatestats, Line 15 [Batch Start Line 0 ] User does not have permission to perform this action. Instead there are several posts that suggest using UPDATE STATISTICS instead: https://dba.stackexchange.com/questions/145982/sp-updatestats-vs-update-statistics I stumbled upon the following post from 2008 (!!!), https://social.msdn.microsoft.com/Forums/sqlserver/en-US/186e3db0-fe37-4c31-b017-8e7c24d19697/spupdatestats-fails-to-run-with-permission-error-under-dbopriveleged-user , which describes a way to wrap the call to sp_updatestats and execute it under a different user: create procedure dbo.sp_updstats with execute as 'dbo' as

Content Delivery Monitoring in AWS with CloudWatch

This post describes a way of monitoring a Tridion 9 combined Deployer by sending the health checks into a custom metric in CloudWatch in AWS. The same approach can also be used for other Content Delivery services. Once the metric is available in CloudWatch, we can create alarms in case the service errors out or becomes unresponsive. The overall architecture is as follows: Content Delivery service sends heartbeat (or exposes HTTP endpoint) for monitoring Monitoring Agent checks heartbeat (or HTTP health check) regularly and stores health state AWS lambda function: runs regularly reads the health state from Monitoring Agent pushes custom metrics into CloudWatch I am running the Deployer ( installation docs ) and Monitoring Agent ( installation docs ) on a t2.medium EC2 instance running CentOS on which I also installed the Systems Manager Agent (SSM Agent) ( installation docs ). In my case I have a combined Deployer that I want to monitor. This consists of an Endpoint and a

Debugging a Tridion 2011 Event System

OK, so you wrote your Tridion Event System. Now it's time to debug it. I know this is a hypothetical situtation -- your code never needs any kind of debugging ;) but indulge me... Recently, Alvin Reyes ( @nivlong ) blogged about being difficult to know how exactly to debug a Tridion Event System. More exactly, the question was " What process do I attach to for debugging even system code? ". Unfortunately, there is no simple or generic answer for it. Different events are fired by different Tridion CM modules. These modules run as different programs (or services) or run inside other programs (e.g. IIS). This means that you will need to monitor (or debug) different processes, based on which events your code handles. So the usual suspects are: dllhost.exe (or dllhost3g.exe ) - running as the MTSUser is the SDL Tridion Content Manager COM+ application and it fires events on generic TOM objects (e.g. events based on Tridion.ContentManager.Extensibility.Events.CrudEven