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Blazor Grid grouping error when using SfDataManager Adaptors IQueryable (18.1.44)

Blazor Grid is giving following error when used with SfDataManager Adaptors IQueryable.
I have attached sample solution with MSSQL2017 database.


blazor.server.js:15 [2020-04-14T15:29:53.153Z] Error: System.InvalidCastException: Unable to cast object of type 'SyncfusionBlazorApp1.Database.Order' to type 'Syncfusion.Blazor.Data.Group`1[SyncfusionBlazorApp1.Database.Order]'.
   at Syncfusion.Blazor.Grids.Internal.GroupModelGenerator`1.GenerateRows(IEnumerable data, Int32 startIndex)
   at Syncfusion.Blazor.Grids.Internal.GridContent`1.OnParametersSet()
   at Microsoft.AspNetCore.Components.ComponentBase.CallOnParametersSetAsync()
   at Microsoft.AspNetCore.Components.ComponentBase.SetParametersAsync(ParameterView parameters)
   at Microsoft.AspNetCore.Components.Rendering.ComponentState.SetDirectParameters(ParameterView parameters)
   at Microsoft.AspNetCore.Components.RenderTree.RenderTreeDiffBuilder.UpdateRetainedChildComponent(DiffContext& diffContext, Int32 oldComponentIndex, Int32 newComponentIndex)
   at Microsoft.AspNetCore.Components.RenderTree.RenderTreeDiffBuilder.AppendDiffEntriesForFramesWithSameSequence(DiffContext& diffContext, Int32 oldFrameIndex, Int32 newFrameIndex)
   at Microsoft.AspNetCore.Components.RenderTree.RenderTreeDiffBuilder.AppendDiffEntriesForRange(DiffContext& diffContext, Int32 oldStartIndex, Int32 oldEndIndexExcl, Int32 newStartIndex, Int32 newEndIndexExcl)
   at Microsoft.AspNetCore.Components.RenderTree.RenderTreeDiffBuilder.AppendDiffEntriesForFramesWithSameSequence(DiffContext& diffContext, Int32 oldFrameIndex, Int32 newFrameIndex)
   at Microsoft.AspNetCore.Components.RenderTree.RenderTreeDiffBuilder.AppendDiffEntriesForRange(DiffContext& diffContext, Int32 oldStartIndex, Int32 oldEndIndexExcl, Int32 newStartIndex, Int32 newEndIndexExcl)
   at Microsoft.AspNetCore.Components.RenderTree.RenderTreeDiffBuilder.AppendDiffEntriesForFramesWithSameSequence(DiffContext& diffContext, Int32 oldFrameIndex, Int32 newFrameIndex)
   at Microsoft.AspNetCore.Components.RenderTree.RenderTreeDiffBuilder.AppendDiffEntriesForRange(DiffContext& diffContext, Int32 oldStartIndex, Int32 oldEndIndexExcl, Int32 newStartIndex, Int32 newEndIndexExcl)
   at Microsoft.AspNetCore.Components.RenderTree.RenderTreeDiffBuilder.AppendDiffEntriesForFramesWithSameSequence(DiffContext& diffContext, Int32 oldFrameIndex, Int32 newFrameIndex)
   at Microsoft.AspNetCore.Components.RenderTree.RenderTreeDiffBuilder.AppendDiffEntriesForRange(DiffContext& diffContext, Int32 oldStartIndex, Int32 oldEndIndexExcl, Int32 newStartIndex, Int32 newEndIndexExcl)
   at Microsoft.AspNetCore.Components.RenderTree.RenderTreeDiffBuilder.ComputeDiff(Renderer renderer, RenderBatchBuilder batchBuilder, Int32 componentId, ArrayRange`1 oldTree, ArrayRange`1 newTree)
   at Microsoft.AspNetCore.Components.Rendering.ComponentState.RenderIntoBatch(RenderBatchBuilder batchBuilder, RenderFragment renderFragment)
   at Microsoft.AspNetCore.Components.RenderTree.Renderer.RenderInExistingBatch(RenderQueueEntry renderQueueEntry)
   at Microsoft.AspNetCore.Components.RenderTree.Renderer.ProcessRenderQueue()

Attachment: SyncfusionBlazorApp1_a1e334.rar

11 Replies
RS Renjith Singh Rajendran Syncfusion Team April 15, 2020 12:07 PM UTC

Hi ashimaz, 

Thanks for contacting Syncfusion support. 

We suggest you to ensure to handle the Grouping codes in your application to overcome the problem you are facing. Please refer the below codes to handle the Grouping and add in your application. 

 
        public override object Read(DataManagerRequest dm, string key = null) 
        { 
            IQueryable<Database.Order> ResultData = _db.Order; 
            IEnumerable DataSource = ResultData.ToList(); 
            DataResult DataObject = new DataResult(); 
            ... 
           if (dm.Sorted != null && dm.Sorted.Count > 0) 
            { 
               DataSource = DataOperations.PerformSorting(DataSource, dm.Sorted); 
            } 
            ... 
           if (dm.Take != 0) 
            { 
                DataSource = DataOperations.PerformTake(DataSource, dm.Take); 
            } 
            if (dm.Group != null) 
            { 
               foreach (var group in dm.Group) 
                { 
                    DataSource = DataUtil.Group<Database.Order>(DataSource, group, dm.Aggregates, 0, dm.GroupByFormatter); 
                } 
                DataObject.Result = DataSource; 
                DataObject.Count = count; 
                return dm.RequiresCounts ? DataObject : (object)DataSource; 
            } 
            return dm.RequiresCounts ? new Syncfusion.Blazor.Data.DataResult() { Result = DataSource, Count = count } : (object)DataSource; 
        } 


Please get back to us if you need further assistance. 

Regards, 
Renjith Singh Rajendran. 


AS ashimaz April 16, 2020 01:39 AM UTC

Hi,

using IEnumerable DataSource = ResultData.ToList(); not efficient with large tables, is there any way to group without using IEnumerable ToList?

RS Renjith Singh Rajendran Syncfusion Team April 16, 2020 09:32 AM UTC

Hi ashimaz, 

Thanks for your update. 

Based on your query, we suggest you to use the below code instead of the previously suggested way to achieve your requirement. Please use the code below, 

 
        public override object Read(DataManagerRequest dm, string key = null) 
        { 
            IQueryable<Database.Order> DataSource = _db.Order; 
            DataResult DataObject = new DataResult(); 
            if (dm.Search != null && dm.Search.Count > 0) 
            { 
               DataSource = DataOperations.PerformSearching(DataSource, dm.Search); 
            } 
            ... 
           if (dm.Take != 0) 
            { 
                DataSource = DataOperations.PerformTake(DataSource, dm.Take); 
            } 
            if (dm.Group != null) 
            { 
                IEnumerable ResultData = Enumerable.Empty<Database.Order>(); 
               foreach (var group in dm.Group) 
                { 
                    ResultData = DataUtil.Group<Database.Order>(DataSource, group, dm.Aggregates, 0, dm.GroupByFormatter); 
                } 
                DataObject.Result = ResultData; 
                DataObject.Count = count; 
                return dm.RequiresCounts ? DataObject : (object)ResultData; 
            } 
            return dm.RequiresCounts ? new Syncfusion.Blazor.Data.DataResult() { Result = DataSource, Count = count } : (object)DataSource; 
        } 


Please get back to us if you need further assistance. 

Regards, 
Renjith Singh Rajendran. 


AS ashimaz April 16, 2020 10:54 AM UTC

Hi, I am unable to try as mentioned. Please find solution file attached.



Attachment: SyncfusionBlazorApp1_f868b65.rar

RS Renjith Singh Rajendran Syncfusion Team April 17, 2020 09:55 AM UTC

Hi ashimaz, 

We suggest you to ensure to add proper namespace for IEnumerable to overcome the problem you are facing. Please add the below namespace to your DataGridFeatures.razor file to overcome this error. And also please modify the below highlighted codes inside the dm.Group if loop condition in your application. 


@using System.Collections  
 
@code{ 
    ... 
    public class CustomAdaptor : DataAdaptor 
    { 
        ... 
       public override object Read(DataManagerRequest dm, string key = null) 
        { 
            IQueryable<Database.Order> DataSource = _db.Order; 
            ... 
            if (dm.Group != null) 
            { 
                IEnumerable ResultData = DataSource.ToList(); 
                // Grouping 
                foreach (var group in dm.Group) 
                { 
                    ResultData = DataUtil.Group<Data.Order>(ResultData, group, dm.Aggregates, 0, dm.GroupByFormatter); 
                } 
                DataObject.Result = ResultData; 
                DataObject.Count = count; 
                return dm.RequiresCounts ? DataObject : (object)ResultData; 
            } 
            return dm.RequiresCounts ? new Syncfusion.Blazor.Data.DataResult() { Result = DataSource, Count = count } : (object)DataSource; 
        } 
        ... 
    } 
} 


As we faced some SQL network related problem with your attached sample, we are attaching a sample similar to your case and codes to perform Grouping in Grid. Please download the sample from the link below, 
 
Please get back to us if you need further assistance.  

Regards, 
Renjith Singh Rajendran. 


AS ashimaz April 18, 2020 07:31 AM UTC

My apologies, I totally forgot to add name space @using System.Collections.
Provided solution is working.

Thank you.

Please find working code for reference.
public class CustomAdaptor : DataAdaptor
    {
        private Database.SyncfusionBlazorApp1Context _db = new Database.SyncfusionBlazorApp1Context();
 
         // Performs data Read operation
        public override object Read(DataManagerRequest dm, string key = null)
        {
            IQueryable.Order> DataSource = _db.Order;
 
            DataResult DataObject = new DataResult();
 
            if (dm.Search != null && dm.Search.Count > 0)
            {
                // Searching
                DataSource = DataOperations.PerformSearching(DataSource, dm.Search);
            }
            if (dm.Sorted != null && dm.Sorted.Count > 0)
            {
                // Sorting
                DataSource = DataOperations.PerformSorting(DataSource, dm.Sorted);
            }
            if (dm.Where != null && dm.Where.Count > 0)
            {
                // Filtering
                DataSource = DataOperations.PerformFiltering(DataSource, dm.Where, dm.Where[0].Operator);
            }
            int count = DataSource.Cast.Order>().Count();
            if (dm.Skip != 0)
            {
                //Paging
                DataSource = DataOperations.PerformSkip(DataSource, dm.Skip);
            }
            if (dm.Take != 0)
            {
                DataSource = DataOperations.PerformTake(DataSource, dm.Take);
            }
 
            if (dm.Group != null)
            {
                IEnumerable ResultData = Enumerable.Empty.Order>();
 
                foreach (var group in dm.Group)
                {
                    ResultData = DataUtil.Group.Order>(DataSource, group, dm.Aggregates, 0, dm.GroupByFormatter);
                }
                DataObject.Result = ResultData;
                DataObject.Count = count;
                return dm.RequiresCounts ? DataObject : (object)DataSource;
            }
 
            return dm.RequiresCounts ? new Syncfusion.Blazor.Data.DataResult() { Result = DataSource, Count = count } : (object)DataSource;
        }
 
        public void Dispose()
        {
            _db = null;
            Dispose(true);
        }
    }





RS Renjith Singh Rajendran Syncfusion Team April 20, 2020 11:04 AM UTC

Hi ashimaz, 

Thanks for your update. 

We are glad to hear that you have achieved your requirement. 

Please get back to us if you need further assistance. 

Regards, 
Renjith Singh Rajendran. 


AS ashimaz May 21, 2020 10:36 PM UTC

Hi,

I am trying to use same code in a Web API, and I receive following error on filtering.



Grid 
<SfDataManager Url="/api/SystemUser" Adaptor="Adaptors.UrlAdaptor">SfDataManager>

RS Renjith Singh Rajendran Syncfusion Team May 22, 2020 09:47 AM UTC

Hi ashimaz, 

Greetings from Syncfusion support. 

We suggest you to ensure to add the below code highlighted code in your Startup.cs file to overcome the problem you are facing.  

 
public void ConfigureServices(IServiceCollection services) 
{ 
    ... 
    services.AddSyncfusionBlazor(); 
    services.AddControllers().AddNewtonsoftJson(options => 
    { 
        options.SerializerSettings.ContractResolver = new DefaultContractResolver(); 
    }); 
    ... 
} 


For this we need to install the below package in your application, 

<PackageReference Include="Microsoft.AspNetCore.Mvc.NewtonsoftJson" Version="3.1.0" />

Please get back to us if you need further assistance. 

Regards, 
Renjith Singh Rajendran 


AS ashimaz May 22, 2020 12:14 PM UTC

Thank you, its working.

RS Renjith Singh Rajendran Syncfusion Team May 25, 2020 07:01 AM UTC

Hi ashimaz, 

Thanks for your update. 

We are glad to hear that the provided suggestion helped you in overcoming the reported problem. 

Please get back to us if you need further assistance. 

Regards, 
Renjith Singh Rajendran 


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