Grouping with custom Adaptor

[Unknown]

Hi

i have a custom grid data adaptor and everything works perfect but the grouping is not working. I couldn't find any example with grouping and tried the following: 

  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);
    }
    else
    {
        var properties = typeof(TTarget).GetProperties().ToList();
// for take and skip we always need one sort prop
        if (properties.Any(a => a.Name == "Id"))
        {
            dataSource = DataOperations.PerformSorting(dataSource, new List<Sort>() {new Sort() {Name = "Id", Direction = "ascending"}});
        }
        else if (properties.Any())
        {
            dataSource = DataOperations.PerformSorting(dataSource, new List<Sort>() {new Sort() {Name = properties.First().Name, Direction = "ascending"}});
        }
        else
        {
            throw new Exception("The grid needs at least one property in the generic model.");
        }
    }

    if (dm.Where != null && dm.Where.Count > 0)
    {
// Filtering
        dataSource = DataOperations.PerformFiltering(dataSource, dm.Where, dm.Where[0].Operator);
    }

    int count = dataSource.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 && dm.Group.Any())
    {
        var test = dataSource;
        var res = DataOperations.PerformGrouping<TTarget>(test, dm.Group);
        return dm.RequiresCounts ? new DataResult() {Result = res, Count = count} : (object) res;
    }

After the data is returned by the read function an exception is thrown in the group model generator.

GroupModelGenerator Line 39:

System.InvalidCastException: Unable to cast object of type 'Syncfusion.Blazor.Data.GroupResult' to type 'Syncfusion.Blazor.Data.Group`1[HQSB.Blazor.Web.DataModel.UserReportingDto]'.

  at at Syncfusion.Blazor.Grids.Internal.GroupModelGenerator`1.GenerateRows(IEnumerable data, Int32 startIndex)

Can you give me a hint?

Thanks in advance.

[Vignesh Natarajan]

Hi Nils,  

 

Greetings from Syncfusion support  

 

Query: “i have a custom grid data adaptor and everything works perfect but the grouping is not working’ 

 

As per your requirement we have prepared a sample to perform Grouping in Grid with CustomAdaptor. Refer the below modified code example.  

 

public override object Read(DataManagerRequest dm, string key = null) 

        { 

  

            IEnumerable 

                DataSource = Orders; 

            DataResult DataObject = new DataResult(); 

. . . .. . . . . 

            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 GroupData = Enumerable.Empty<object>(); 

                foreach (var group in dm.Group) 

                { 

                    DataSource = DataUtil.Group<Order>(DataSource, group, dm.Aggregates, 0, dm.GroupByFormatter); 

                } 

                DataObject.Result = DataSource; 

                DataObject.Count = count; 

                return dm.RequiresCounts ? DataObject : (object)DataSource; 

            } 

            return dm.RequiresCounts ? new DataResult() { Result = DataSource, Count = count } : (object)DataSource; 

        } 

 

 

Kindly download the sample which we have prepared using 18.1.0.36-beta from below  

Sample: https://www.syncfusion.com/downloads/support/forum/152692/ze/BlazorApp1-1840415020  

 

Please get back to us if you have further queries.  

 

Regards, 

Vignesh Natarajan. 

 

[Unknown]

Works perfect, thank you so much.

[Vignesh Natarajan]

Hi Nils,  

Thanks for the update.  

We are glad to hear that you have resolved your query using our solution.  

Kindly get back to us if you have further queries.  

Regards, 

Vignesh Natarajan.