My favorite approach for this type of thing (if your site isn't too large!) is the XPath operator. (Yes, you can do this in RAZOR, not just XSLT!)

For example:

var articleRoot = Library.NodeById(1234); // or however else you want to find this...
var categoryFolderNodeId = 333; // Current category. You could get this from current Node.Id or the querystring???
string query = String.Format(@".//article[categoryPicker/MultiNodePicker/nodeId = ""{0}""]", categoryFolderNodeId);
var articles = articleRoot.XPath(query);

Note the above is for version 4, with my MNTP storing values as XML. In Umbraco version 6 the XPath helper is renamed to Umbraco.ContentAtXPath but works pretty much the same. And if your MNTP stores values as CSV you'd have to change the Xpath query but the idea would be the same.

Good luck to you!

Thanks Funka. Good old XPath!

This looks like it'll do just the job but I'm having a little trouble with the implementation, presumably because this is in a partial view. I've tried this:

var articleRoot = Umbraco.TypedContent(1100);
var categoryFolderNodeId = 1058;
string query = String.Format(@".//article[categoryPicker/MultiNodePicker/nodeId = ""{0}""]", categoryFolderNodeId);
var articles = articleRoot.ContentAtXPath(query);

...and this:

var articleRoot = Umbraco.Content(1100);
var categoryFolderNodeId = 1058;
string query = String.Format(@".//article[categoryPicker/MultiNodePicker/nodeId = ""{0}""]", categoryFolderNodeId);
var articles = articleRoot.ContentAtXPath(query);

But both error (the first says "'Umbraco.Core.Models.IPublishedContent' does not contain a definition for 'ContentAtXPath' and no extension method 'ContentAtXPath' accepting a first argument of type 'Umbraco.Core.Models.IPublishedContent' could be found (are you missing a using directive or an assembly reference?)" (I'm referencing Umbraco.Core, Umbraco.Web and Umbraco.Core.Models), the second just says "Object reference not set to an instance of an object.").

Presumably it's because articleRoot isn't giving me the correct type of content to work with or something in the API has perhaps changed? I'm using Umbraco 6.1.6 by the way.

Do you have any idea how to get this working in the context of a partial?

Thanks!

Thanks. Having hard-coded some XPath in there to test this method works, so that's really handy to know - thank you! However, my MNTP just happens to store its values as CSV rather than XML (as CSV tends to be more easily processed with Razor) so rather than change this (and it looks like it could have been tricky to 'query' the CSV in the XPath) I thought I'd try another approach and go the all-razor route.

So here's what I've come up with, which seems to work, and doesn't involve mixing XPath/XML with Razor:

@{
    // Get container id
    var articleContainerId = 1100;
    // Get category id (id of current page)
    var categoryId = Model.Id.ToString();
    // Get articles from container folder which are associated with current category
    var articles = Umbraco.TypedContent(articleContainerId).Children.Where(x => x.GetPropertyValue<string>("category").Split(',').Contains(categoryId));

    // Loop though nodes and output node name
    foreach (var child in articles){
        <p>@child.Name</p>
    }
}

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