As far as I can tell, these extension methods are no longer available in Umbraco V8 (at least not on IPublishedContent).

I've noticed you've posted a few times about extension methods - so it might be worthwhile to look at the PublishedContentExtensions class on Umbraco's Github, to give you a better idea of what's changed since V7 - which you can find here.

Hello Rhys,

Will they be available afterwards ?

Some of the extension methods in v7 has not been included in v8: https://github.com/umbraco/Umbraco-CMS/issues/4839

But you should be able to get the same node as Previous() or Next() extension methods in v7 but using Siblings(), SiblingsOfType() or SiblingsAndSelf(): https://github.com/umbraco/Umbraco-CMS/issues/4839

https://github.com/umbraco/Umbraco-CMS/blob/v8/dev/src/Umbraco.Web/PublishedContentExtensions.cs

When looking at v7 source code, it used index of the specified node:

Previous:

https://github.com/umbraco/Umbraco-CMS/blob/v7/dev/src/Umbraco.Web/PublishedContentExtensions.cs#L1562-L1565

Next:

https://github.com/umbraco/Umbraco-CMS/blob/v7/dev/src/Umbraco.Web/PublishedContentExtensions.cs#L1493-L1496

Looking at the v8 source code, this might be a workaround for the previous Previous() and Next() extension methods, e.g. in a TextPage view.

string culture = Model.GetCulture()?.Name;
var siblings = Model.Parent != null ? Model.Parent.Children(x => x.Id != Model.Id) : UmbracoContext.ContentCache.GetAtRoot().Where(x => !x.ContentType.VariesByCulture() || x.HasCulture(culture));
var prev = siblings.LastOrDefault(x => x.SortOrder < Model.SortOrder);
var next = siblings.FirstOrDefault(x => x.SortOrder > Model.SortOrder);

In newer versions of Umbraco v8, it is possible to use the Siblings() extensions methods, so this can be simplified further:

string culture = Model.GetCulture()?.Name;
var siblings = Model.Siblings(culture);
var prev = siblings.LastOrDefault(x => x.SortOrder < Model.SortOrder);
var next = siblings.FirstOrDefault(x => x.SortOrder > Model.SortOrder);

These might be alternative to PrecedingSibling() and FollowingSibling() extension methods as I think in v7 that Previous() extension method returned the parent node if the current node was the first child node.

/Bjarne

Navigating the tree is an expensive operation, and providing Previous/Next sibling navigation required some more expensive plumbing. That plumbing is gone in v8.

Note that it was the same plumbing that provided IsOdd/IsEven and other funny helper methods.

Depending on what you are trying to achieve... Model.Children().ToindexedArrayItem() will produce an array of items, which all have a Content property (the actual content item) and IsFirst(), IsOdd() etc helper methods. And, being an array, you can navigate with indexes.

That's convenient and relatively cheap, when you're trying to do IsOdd/IsEven when styling a grid, or things like that.

For anything more complex, using Siblings, as suggested, would be the way to go - but what would be the use case exactly?

UMBRACO 8.x Before finding this thread, I knocked together this for BlogPosts:

var prevPost = Model.SiblingsOfType(Blogpost.ModelTypeAlias).OrderBy(x => new Blogpost(x).PublishedDate).Where(x => new Blogpost(x).PublishedDate >= Model.PublishedDate).Take(1).FirstOrDefault();
var nextPost = Model.SiblingsOfType(Blogpost.ModelTypeAlias).OrderByDescending(x => new Blogpost(x).PublishedDate).Where(x => new Blogpost(x).PublishedDate <= Model.PublishedDate).Take(1).FirstOrDefault();

Does the job, not sure how the performance compares.

Could be simplified if you were using CreatedDate instead of your own date.

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