What is Pipeline?
Pipeline is series of step that is defined to show the sequence.
A pipeline is basically a method whose flow is defined using XML.
A pipeline consists of a sequence of Processor. A processor is a .NET class that implements a method. When a pipeline is invoked, the processors are run in order.
Pipelines are defined in Sitecore.Config and in Sitecore patch files.
The following is an example of the pipeline that is responsible for rendering a page:
Adding Custom Processor
There were multiple scenario where you might have to create the custom Processor.
Generally on website you will see 404 message when Item not found, In that case you might have to display the custom page. Below is the step for doing.
Create a new config file and provide a name ErrorResolver.config.
In above configurations, I am using Patch Attribure to inject the custom process in HttpRequestBegin pipeline after the ItemResolver Processor.
Error404Resolver.cs
using Sitecore.Pipelines.HttpRequest;
namespace MyProject.Sitecore.Commands
{
public class Error404 : HttpRequestProcessor
{
if (CoreSite.Context.Item == null)
{
CoreSite.Context.Item = s Sitecore.Context.Database.GetItem.GetItem(“/sitecore/content/Error404”);
}
}
}
Above class help to attach the custom Sitecore item whenever the Error404 occurred.
References
http://sitecore-community.github.io/docs/pipelines-and-events/pipelines/
appdevsitecore 