Inbound request pipeline

How the Umbraco inbound request pipeline works

The inbound process is triggered by UmbracoRouteValueTransformer and then handled with the Published router. The published content request preparation process kicks in and creates a PublishedRequestBuilder which will be used to create a PublishedContentRequest.

The PublishedContentRequest object represents the request which Umbraco must handle. It contains everything that will be needed to render it. All this occurs when the Umbraco modules knows that an incoming request maps to a document that can be rendered.

public class PublishedContentRequest
{
  public Uri Uri { get; }
  …
}

There are 3 important properties, which contains all the information to find a node:

public bool HasDomain { get; }
public DomainAndUri Domain { get; }
public CultureInfo Culture { get; }

Domain is a DomainAndUri object that is a standard Domain plus the fully qualified uri. For example, the Domain may contain "example.com" whereas the Uri will be fully qualified for example "https://example.com/".

It contains the content to render:

public bool HasPublishedContent { get; }
public IPublishedContent PublishedContent { get; set; }
public bool IsInternalRedirect { get; }
public bool IsRedirect {get; }

Contains template information:

public bool HasTemplate { get; }
public string GetTemplateAlias { get; }
public ITemplate Template {get; }

The published request is created using the PublishedRequestBuilder, which implements IPublishedRequestBuilder. It's only in this builder that it's possible to set values, such as domain, culture, published content, redirects, and so on.

You can subscribe to the 'routing request' notification, which is published right after the PublishedRequestBuilder has been prepared, but before the request is built, and processed. Here you can modify anything in the request before it is built and processed! For example content, template, etc:

using Umbraco.Cms.Core.Events;
using Umbraco.Cms.Core.Notifications;

namespace Umbraco9.NotificationHandlers;

public class PublishedRequestHandler : INotificationHandler<RoutingRequestNotification>
{
    public void Handle(RoutingRequestNotification notification)
    {
        var requestBuilder = notification.RequestBuilder;
        // Do something with the IPublishedRequestBuilder here 
    }
}