IContentFinder
To create a custom content finder, with custom logic to find an Umbraco document based on a request, implement the IContentFinder interface:
public interface IContentFinder
{
bool TryFindContent(PublishedRequest contentRequest);
}
and use a composer to add to it to the ContentFindersCollection.
Umbraco runs all content finders in the collection 'in order', until one of the IContentFinders returns true, and then the request is handled by that finder, and no further IContentFinders are executed. Therefore the order in which ContentFinders are added to the ContentFinderCollection is important.
The ContentFinder can set the PublishedContent item for the request, or template or even execute a redirect…
Example
This IContentFinders will find a document with id 1234, when the Url begins with /woot
public class MyContentFinder : IContentFinder
{
public bool TryFindContent(PublishedRequest contentRequest)
{
// handle all requests beginning /woot...
var path = contentRequest.Uri.GetAbsolutePathDecoded();
if (!path.StartsWith("/woot"))
return false; // not found
// have we got a node with ID 1234?
var content = contentRequest.UmbracoContext.Content.GetById(1234);
if (content == null) return false; // not found let another IContentFinder in the collection try to find a document
// render that node
contentRequest.PublishedContent = content;
return true;
}
}
Adding and removing IContentFinders
Use a composer to access the ContentFinderCollection to add and remove specific ContentFinders...
using Umbraco.Core;
using Umbraco.Core.Composing;
using Umbraco.Web;
using Umbraco.Web.Routing;
namespace My.Website
{
[RuntimeLevel(MinLevel = RuntimeLevel.Run)]
public class UpdateContentFindersComposer : IUserComposer
{
public void Compose(Composition composition)
{
//add our custom MyContentFinder just before the core ContentFinderByUrl...
composition.ContentFinders().InsertBefore<ContentFinderByUrl, MyContentFinder>();
//remove the core ContentFinderByUrl finder:
composition.ContentFinders().Remove<ContentFinderByUrl>();
//you can use Append to add to the end of the collection
composition.ContentFinders().Append<AnotherContentFinderExample>();
//or Insert for a specific position in the collection
composition.ContentFinders().Insert<AndAnotherContentFinder>(3);
}
}
}
In Umbraco7 there existed an IContentFinder that would find content and display it with an 'alternative template' via a convention. This could be to avoid the ugly ?alttemplate=blogfullstory
appearing on the querystring of the url when using the alternative template mechanism. Instead the Url could follow the convention of /urltocontent/altemplatealias
.
Eg: /blog/my-blog-post/blogfullstory
would 'find' the /blog/my-blog-post
page and display using the blogfullstory
template.
In Umbraco 8 this convention has been removed from the default configuration of Umbraco. You can reintroduce this behaviour by adding the ContentFinderByUrlAndTemplate
ContentFinder back into the ContentFinderCollection, using an IUserComposer
(see above example).
NotFoundHandlers
To set your own 404 finder create an IContentLastChanceFinder and set it as the ContentLastChanceFinder. (perhaps you have a multilingual site and need to find the appropriate 404 page in the correct language)
A ContentLastChanceFinder will always return a 404 status code. This example creates a new implementation of the IContentLastChanceFinder and checks whether the requested content could not be found by using the default Is404
property presented in the PublishedRequest
class.
using Umbraco.Core.Models.PublishedContent;
using Umbraco.Core.Services;
using Umbraco.Web;
using Umbraco.Web.Routing;
namespace My.Website.ContentFinders
{
public class My404ContentFinder : IContentLastChanceFinder
{
private readonly IDomainService _domainService;
public My404ContentFinder(IDomainService domainService)
{
_domainService = domainService;
}
public bool TryFindContent(PublishedRequest contentRequest)
{
//find the root node with a matching domain to the incoming request
var allDomains = _domainService.GetAll(true).ToList();
var domain = allDomains.FirstOrDefault(f => f.DomainName == contentRequest.Uri.Authority
|| f.DomainName == "http://" + contentRequest.Uri.Authority
|| f.DomainName == "https://" + contentRequest.Uri.Authority);
var siteId = domain != null ? domain.RootContentId : allDomains.Any() ? allDomains.FirstOrDefault()?.RootContentId : null;
var siteRoot = contentRequest.UmbracoContext.Content.GetById(false, siteId ?? -1);
if (siteRoot == null)
{
siteRoot = contentRequest.UmbracoContext.Content.GetAtRoot().FirstOrDefault();
}
if (siteRoot == null)
{
return false;
}
//assuming the 404 page is in the root of the language site with alias fourOhFourPageAlias
var notFoundNode = siteRoot.Children.FirstOrDefault(f => f.ContentType.Alias == "fourOhFourPageAlias");
if (notFoundNode != null)
{
contentRequest.PublishedContent = notFoundNode;
}
// return true or false depending on whether our custom 404 page was found
return contentRequest.PublishedContent != null;
}
}
}
Example on how to register your own implementation:
using Umbraco.Core;
using Umbraco.Core.Composing;
using Umbraco.Web;
namespace My.Website
{
[RuntimeLevel(MinLevel = RuntimeLevel.Run)]
public class SetLastChanceContentFindersComposer : IUserComposer
{
public void Compose(Composition composition)
{
//set the last chance content finder
composition.SetContentLastChanceFinder<My404ContentFinder>();
}
}
}
To make sure your custom 404 page is served set the error404
in umbracoSettings.config
to 0.