Myujth

I'm trying to implement ajax pagination using Umbraco.

On the server side, I have the following:

[System.Web.Http.HttpGet]
public JsonResult pagination(int? page)

IEnumerable<IPublishedContent> newsPosts = Umbraco.AssignedContentItem.DescendantOrSelf("news").Children.Where(x => x.IsVisible() && x.DocumentTypeAlias == "newsPost").OrderByDescending(x => x.UpdateDate).Take(5);

 //from here on we will be returning the json within which information required for displaying post entries in carousel is included.
 string json = "[some random string]"; //just random string for now.
 return Json(json, JsonRequestBehavior.AllowGet);

As you can see, I'm trying to get necessary data from IPublishedContents, but I'm having trouble instantiating this series of IPublishedContents.

And this is the error I'm getting when I access:

locahost:port/umbraco/surface/controller/pagination on Chrome.

Cannot return the IPublishedContent because the UmbracoHelper was constructed with an UmbracoContext and the current request is not a front-end request.

Details: System.InvalidOperationException: Cannot return the IPublishedContent because the UmbracoHelper was constructed with an UmbracoContext and the current request is not a front-end request.

As I said, I'm making this request from Chrome, which is I think means this request is from the front end, so I'm not sure why I'm getting this error.

In the course of searching I found these

1) our.umbraco.com forum
2) stackoverflow post

1. is deserted with no answer, and as for 2, it strikes me that the answer is not quite relevant to my case. I want to instantiate IPublishedContent in the first place.

Mine is Umbraco 7.

and could it be possible to tell me why requests from the front-end are not desirable?

Any hint would be highly appreciated.

Thanks,

Perhaps easier to use web api

Create a controller which inherits from UmbracoApiController

public class PagedItemsController : UmbracoApiController

 [HttpGet]
 [ActionName("list")] //Optional see note below
 public IHttpActionResult GetItems([FromUri] int pageNo = 1)
 
 // Next you need some way of getting the items you need. 
 // I would not return the whole IPublishedContent items. Rather query those and then use linq Select to transform into a more relevant smaller class (not doing this here)
 // I've just included this for brevity
 var items = _itemService.GetPagedItems(pageNo);

 // Now return the results
 return Ok(items);
 

Calls to endpoints in Umbraco follow the format

/umbraco/api/controller/endpoint

With the [ActionName("list")] above the call to the GetItems method will be

http://example.com/umbraco/api/PagedItems/list?pageNo=3

Without the ActionName attribute the call would be

http://exampe.com/umbraco/api/PagedItems/GetItems?pageNo=3

With a standard jquery ajax call this will return json without needing to serialise.

Try getting your node this way.

var umbracoHelper = new Umbraco.Web.UmbracoHelper(Umbraco.Web.UmbracoContext.Current);
var yourNode = umbracoHelper.TypedContentAtXPath("umbracoPathtoYourNode");