Pending Review
Last Updated: 08 Mar 2019 12:13 by ADMIN

When you create a Grid using a TModel that inherits from DynamicObject, a type cast exception is thrown when setting the DataSource Model Id property.

public class Metadata : DynamicObject

{ ... }  


...
.DataSource(dataSource =>
{
    dataSource.Ajax()
      .Model(model =>
      {
          model.Id("Id");
      });
})

A type cast exception is thrown by the following line in Kendo\AspNet.Core\Kendo.Mvc\UI\DataSource\Fluent\DataSourceModelDescriptorFactoryBase.cs because ModelDynamicDataKey is not generic, so it cannot be cast to IDataKey<TModel>

dataKey = (IDataKey<TModel>)new ModelDynamicDataKey(fieldName, lambdaExpression);


The following code changes fix the issue:

DataSourceModelDescriptorFactoryBase.cs

namespace Kendo.Mvc.UI.Fluent
{
	using System.Reflection;
	using Extensions;

	/// <summary>
	/// Defines the fluent interface for configuring the <see cref="DataSource"/> Model definition.
	/// </summary>
	/// <typeparam name="TModel">Type of the model</typeparam>
	public abstract class DataSourceModelDescriptorFactoryBase<TModel> : IHideObjectMembers
        where TModel : class
    {
        protected readonly ModelDescriptor model;

        public DataSourceModelDescriptorFactoryBase(ModelDescriptor model)
        {
            this.model = model;
        }

        /// <summary>
        /// Specify the member used to identify an unique Model instance.
        /// </summary>
        /// <param name="fieldName">The member name.</param>
        protected void Id(string fieldName)
        {
            IDataKey<TModel> dataKey;
            if (typeof(TModel).IsDynamicObject())
            {
                var lambdaExpression = ExpressionBuilder.Expression<TModel, object>(fieldName);
                dataKey = new ModelDynamicDataKey<TModel>(fieldName, lambdaExpression);
            }
            else
            {
                dataKey = GetDataKeyForField(fieldName);
            }

            dataKey.RouteKey = dataKey.Name;

            model.Id = dataKey;
        }

        protected IDataKey<TModel> GetDataKeyForField(string fieldName)
        {
            var lambdaExpression = ExpressionBuilder.Lambda<TModel>(fieldName);
            var fieldType = typeof(ModelDataKey<,>).MakeGenericType(new[] { typeof(TModel), lambdaExpression.Body.Type });

            var constructor = fieldType.GetConstructor(new[] { lambdaExpression.GetType() });

            return (IDataKey<TModel>)constructor.Invoke(new object[] { lambdaExpression });
        }
    }
}

 

ModelDynamicDataKey.cs

namespace Kendo.Mvc.UI
{
    using System;
    using System.Linq.Expressions;
    using Microsoft.AspNetCore.Mvc.Rendering;

    internal class ModelDynamicDataKey<TModel> : IDataKey<TModel>
        where TModel : class
    {
        public ModelDynamicDataKey(string memberName, Expression<Func<TModel, object>> expression)
        {
            RouteKey = "id";
            Name = memberName;
            Expression = expression;
            Value = expression.Compile();
        }

        public string Name
        {
            get;
        }

        public string RouteKey
        {
            get;
            set;
        }

        public Func<TModel, object> Value
        {
            get;
        }

        public Expression<Func<TModel, object>> Expression
        {
            get;
        }

        public object GetValue(object dataItem)
        {
            try
            {
                return Value((TModel)dataItem);
            }
            catch (Microsoft.CSharp.RuntimeBinder.RuntimeBinderException)
            {
                return null;
            }
        }

        public string HiddenFieldHtml(IHtmlHelper<TModel> htmlHelper)
        {
            return htmlHelper.Hidden(Name, null, new { id = "" }).ToString();
        }
    }
}


Pending Review
Last Updated: 17 Oct 2019 11:36 by ADMIN

Hi!

We're using a drop down list as a grid cell's edit template, but.. our users are unable to properly edit the rows at the bottom of the grid due to drop down list going off the page, and closing when they attempt to scroll.

 

any ideas?

Pending Review
Last Updated: 30 Jan 2019 09:34 by ADMIN

Hi,

We have a property EnableHeaderContextAggregateMenu in Radgrid. By enabling this, we can aggregate any column in the Radgrid and show the result value in the corresponding column footer at runtime by the end user.

Do we have similar property in Kendo UI Grid? We need to implement this in Kendo UI Grid which has dynamic column data binding. We had attached a sample code here. Can you please implement the same in the code and revert?

Thanks & Regards,
Shivakumar. K