A DD4T ComponentFactory is in charge of retrieving or searching for IComponent models by using either serving them from local cache or delegating the call to a ComponentProvider that uses the Tridion Broker API to look things up in the Content Delivery database.
When retrieving Component models, the ComponentFactory uses a couple of methods that take as parameters the TcmUri of the Component and a Component Template TcmUri.
The default ComponentFactory from DD4T .net v1.31 has been written in a relaxed fashion, and don't enforce a mandatory Component Template TcmUri. If a lazy developer chooses not to pass a templateUri, the code still works. However, the call to the Content Delivery database is not cached. This results in performance degradation when the internal DD4T cache is expired, and a new call to a previously retrieved Component is made. The request will make all its way to the database.
This issue can easily be prevented by passing a Component Template TcmUri to these two methods. However, developers being lazy people, I want to enforce the second parameter to be passed and to have a valid TcmUri in it.
As such, I created my own CachingComponentFactory class as a specialization of the DD4T default ComponentFactory, where I overrode the two methods:
The code is very straight forward and expects the second TcmUri parameter to be passed and to be a valid TcmUri. Anything else results is a ComponentNotFoundException.
The only thing left to do is to wire up my CachingComponentFactory in Ninject so that it is used every time an IComponentFactory instance is requested.
When retrieving Component models, the ComponentFactory uses a couple of methods that take as parameters the TcmUri of the Component and a Component Template TcmUri.
IComponent GetComponent(string componentUri, string templateUri = "");
bool
TryGetComponent(string componentUri, out IComponent component, string templateUri = "");
This issue can easily be prevented by passing a Component Template TcmUri to these two methods. However, developers being lazy people, I want to enforce the second parameter to be passed and to have a valid TcmUri in it.
As such, I created my own CachingComponentFactory class as a specialization of the DD4T default ComponentFactory, where I overrode the two methods:
public class CachingComponentFactory : ComponentFactory, IComponentFactory
{
public new IComponent GetComponent(string componentUri, string templateUri)
{
if
(!UriHelper.IsValidTcmUri(templateUri))
{
throw new ComponentNotFoundException();
}
return base.GetComponent(componentUri,
templateUri);
}
public new bool TryGetComponent(string componentUri, out IComponent component, string templateUri)
{
if
(!UriHelper.IsValidTcmUri(templateUri))
{
component = null;
return false;
}
return base.TryGetComponent(componentUri,
out component, templateUri);
}
}
The only thing left to do is to wire up my CachingComponentFactory in Ninject so that it is used every time an IComponentFactory instance is requested.
Bind<IComponentFactory>().To<CachingComponentFactory>().InSingletonScope();
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