In the example below products is actually DbSet<Product>

public async Task<ActionResult> Products_Read([DataSourceRequest]DataSourceRequest request)
{
    using (var northwind = new SampleEntities())
    {
        IQueryable<Product> products = northwind.Products;
        DataSourceResult result = await products.ToDataSourceResultAsync(request);
        return Json(result);
    }
}

Under the hood the ToDataSourceResultAsync call is executed inside Task.Run

And that Task.Run is calling sync methods of IQueryable which means EntityframeworkCore queries are not taking place with async I/O

I came up with something like below. But couldnt figured out how to support groups and aggregates.

It works with filters, sorts and paging.

        public static Task<AsDataSourceResult<TResult>> ToAsDataSourceResult<TModel, TResult>(this IQueryable<TModel> enumerable, DataSourceRequest request, Func<TModel, TResult> selector)
        {
            return enumerable.AsCreateDataSourceResultAsync(request, selector);
        }

        private static async Task<AsDataSourceResult<TResult>> AsCreateDataSourceResultAsync<TModel, TResult>(this IQueryable<TModel> queryable, DataSourceRequest request, Func<TModel, TResult> selector)
        {
            var result = new AsDataSourceResult<TResult>();

            var data = queryable;

            if (request.Filters.Count > 0)
                data = (IQueryable<TModel>)data.Where(request.Filters);

            result.Total = await data.CountAsync();

            var sort = new List<SortDescriptor>();

            if (request.Sorts != null)
                sort.AddRange(request.Sorts);

            if (sort.Count == 0 && queryable.Provider.IsEntityFrameworkProvider())
            {
                // The Entity Framework provider demands OrderBy before calling Skip.
                var sortDescriptor = new SortDescriptor
                {
                    Member = queryable.ElementType.FirstSortableProperty()
                };
                sort.Add(sortDescriptor);
            }

            if (sort.Count > 0)
                data = (IQueryable<TModel>)data.Sort(sort);

            data = data.Page(request.Page - 1, request.PageSize);

            var list = new List<TResult>();

a

            result.Data = list;

            return result;
        }

        private static IQueryable<TResult> Page<TResult>(this IQueryable<TResult> source, int pageIndex, int pageSize)
        {
            var query = source;

            query = query.Skip(pageIndex * pageSize);

            if (pageSize > 0)
                query = query.Take(pageSize);

            return query;
        }

        private static string FirstSortableProperty(this Type type)
        {
            var firstSortableProperty = type.GetProperties().FirstOrDefault(property => property.PropertyType.IsPredefinedType()) ?? throw new NotSupportedException("Exceptions.CannotFindPropertyToSortBy");
            return firstSortableProperty.Name;
        }

        private static bool IsEntityFrameworkProvider(this IQueryProvider provider)
        {
            var name = provider.GetType().FullName;
            return name == "System.Data.Objects.ELinq.ObjectQueryProvider" ||
                    name == "System.Data.Entity.Core.Objects.ELinq.ObjectQueryProvider" ||
                    name.StartsWith("LinqKit.ExpandableQueryProvider") ||
                    name.StartsWith("Microsoft.Data.Entity.Query.EntityQueryProvider") ||
                    name.StartsWith("System.Data.Entity.Internal.Linq");
        }

AsDataSourceResult<TResult> is wrapper for typed access to DataSourceResult

How do i support all operations which ToDataSourceResult (sync) one supports.

I have list of tabs in my model like

In cshtml: my Tabstrip looks like this

Since Html.Action is no longer works in .net 8. Need suggestion to overcome this issue.
Now, I'm unable to navigate to the page which has this tabstrip due to Html.Action issue

I have a grid with the following template columns:

columns.Template("<input type='checkbox' />");
columns.Template("<input type='hidden' value='#=Ssid#' />");

Html.Kendo().Template().AddHtml() cannot be used because it does not return a string.

How can I rewrite the code to be compatible with a strict content security policy (e.g. without using unsafe-inline)?

Thank you

Grouping colapsed after the save.

Grouping should be in the same state as before the save 

Need help on this issue. will waiting for you response.

We have a complicated Kendo Grid with Tag Helper notification. We need to use On Cancel Event within edit operation, by pressing Cancel button. Here is an example (but not Tag Helper)

I have an Editor on a page and there are several Content Security Policy violations in the console. Here is an example:

Refused to apply inline style because it violates the following Content Security Policy directive: "style-src-attr 'unsafe-hashes' 'sha256-aqNNdDLnnrDOnTNdkJpYlAxKVJtLt9CtFLklmInuUAE='". Either the 'unsafe-inline' keyword, a hash ('sha256-5TmCSWsRHHKtNC4AgS23KS5Z9SBqma0xikI6H6iJ1/Y='), or a nonce ('nonce-...') is required to enable inline execution.

Is it possible to use an Editor without adding unsafe-inline to style-src-attr?

Thank you

Hello

We are currently working on improving the content security policy header of our application to remove the unsafe-inline and unsafe-eval for the script element.

I am facing some issues when using the Template element with the generated deferred javascript mostly in the grid and I hope someone could help me with that. 

Firstly, I'd like to know if there are some tag helpers that could be used to generate some template. To be more explicit : we use some shared and partial views to render the components in edition mode in our grids. These views are written using tag helpers, for instance we have the following file Views\Shared\EditorTemplates\DateTime.cshtml : 

@model DateTime
 
<kendo-datetimepicker asp-for="@Model" />

Used in our grids :

column.Bound(User => User.DateCreated).EditorTemplateName("DateTime")

(this is a basic example but we have some more complex views using home made components with taghelper syntax)

I noticed there is a kendo-template tag helper and I would like to know if there is any way to use it in our views, so I could replace my view with the following code and use the EditorTemplateComponentName extension method in my grid :

<kendo-template>
    <kendo-datetimepicker asp-for="@Model" />
</kendo-template>

When I tried to do this I have an exception :

Secondly, I noticed an issue when using some kendo elements in editor templates: the javascript rendered in the deferred script file includes the initialisation scripts at the root of the script file. This mainly cause some issues in my pages when some other element has the same names (but I think it can lead to some other issues).

For instance, I have the following column definition in my grid:

<columns>
    <column field="FullName" title="FullName"></column>
    <column field="DateCreated" title="DateCreated">
        <column-editor-template>
            <kendo-datetimepicker name="dateCreated"></kendo-datetimepicker>
        </column-editor-template>
    </column>
</columns>

Then in the kendo-deferred-script javascript file I can see the dateCreated element is inialized at the beginning of the file and in the template function:

I'm joining a sample application with both cases to help reproduce the issues.

Is there something I'm doing wrong or any improvement coming in the next versions to fix these issues ?

Thanks in advance

Yael