KendoNET.DynamicLinq 3.1.2

KendoNET.DynamicLinq

Description

KendoNET.DynamicLinq implements server paging, filtering, sorting, grouping, and aggregating to Kendo UI via Dynamic Linq for .Net Core App(1.x ~ 3.x).

Prerequisites

.Net Core 1 ~ 2

• None

.Net Core 3

• You must add custom ObjectToInferredTypesConverter to your JsonSerializerOptions since System.Text.Json didn't deserialize inferred type to object properties now, see the sample code and reference.

Usage

1. Add the KendoNET.DynamicLinq NuGet package to your project.
2. Configure your Kendo DataSource to send its options as JSON.

parameterMap: function(options, type) {
    return JSON.stringify(options);
}

3. Configure the schema of the dataSource.

schema: {
    data: "Data",
    total: "Total",
    aggregates: "Aggregates",
    groups: "Groups",
    errors: "Errors"
}

4. The completed code like below.

..... Other kendo grid code .....

dataSource: {
    schema:
    {
        data: "Data",
        total: "Total",
        aggregates: "Aggregates",
        groups: "Groups",
        errors: "Errors",
        ...
    },
    transport: {
        read: {
            url: 'your read url',
            dataType: 'json',
            contentType: 'application/json; charset=utf-8',
            type: 'POST'
        },
        create: {
            url: 'your create url',
            dataType: "json",
            contentType: 'application/json; charset=utf-8',
            type: 'POST'
        },
        parameterMap: function (data, operation) {
            return JSON.stringify(data);
        }
    },
    error: function(e) {
        console.log(e.errors); // Your error information
        e.sender.cancelChanges();
    },
    pageSize: 20,
    serverPaging: true,
    serverFiltering: true,
    serverSorting: true,
    ...
}

..... Other kendo grid code .....

5. Import the KendoNET.DynamicLinq namespace.
6. Use the ToDataSourceResult extension method to apply paging, sorting, filtering, grouping and aggregating.

using KendoNET.DynamicLinq

[WebMethod]
public static DataSourceResult Products(int take, int skip, IEnumerable<Sort> sort, Filter filter, IEnumerable<Aggregator> aggregates, IEnumerable<Group> groups)
{
    using (var northwind = new Northwind())
    {
        return northwind.Products
               .OrderBy(p => p.ProductID) // EF requires ordering for paging
               .Select(p => new ProductViewModel // Use a view model to avoid serializing internal Entity Framework properties as JSON
               {
                   ProductID = p.ProductID,
                   ProductName = p.ProductName,
                   UnitPrice = p.UnitPrice,
                   UnitsInStock = p.UnitsInStock,
                   Discontinued = p.Discontinued
               })
               .ToDataSourceResult(take, skip, sort, filter, aggregates, groups);
    }
}

or from Kendo UI request

using KendoNET.DynamicLinq

[HttpPost]
public IActionResult Products([FromBody] DataSourceRequest requestModel)
{
    using (var northwind = new Northwind())
    {
        return northwind.Products
               .Select(p => new ProductViewModel // Use a view model to avoid serializing internal Entity Framework properties as JSON
               {
                   ProductID = p.ProductID,
                   ProductName = p.ProductName,
                   UnitPrice = p.UnitPrice,
                   UnitsInStock = p.UnitsInStock,
                   Discontinued = p.Discontinued
               })
               .ToDataSourceResult(requestModel.Take, requestModel.Skip, requestModel.Sort, requestModel.Filter, requestModel.Aggregate, requestModel.Group);
    }
}

Known Issues

When server-side filterable options are enabled and apply a query with filter condition that contains DateTime type column, then EntityFramework Core would throw an exception System.Data.SqlClient.SqlException (0x80131904): Conversion failed when converting date and/or time from character string. The error is caused by a known issue in some old EntityFramework Core versions. The workaround is adding datetime value to the related column in DbContext. e.g.

public class MyContext : DbContext
{
    protected override void OnModelCreating(ModelBuilder modelBuilder)
    {
        ..........

        modelBuilder.Entity<Member>().Property(x => x.UpdateTime).HasColumnType("datetime");

        ..........
    }
}