Hierarchy Editing

Environment

Product Grid for Blazor

Description

This article showcases how to Create, Update and Delete items in both the main and nested Grids in a hierarchy.

Solution

The CRUD operations are independent from the Hierarchy. Each Grid has it`s own handlers.

The example below showcases those separate handlers and also how you can get the parent model from the nested grid handlers in case you need information from it - the UpdateOrder, CreateOrder and DeleteOrder handlers are getting the context in order to access the Data from the parent. If you do not need access to the main Grid you should not pass the context through a lambda function.

You can set the EditMode of the nesting grid to either Popup, Inline, Incell. By default it is Inline.

How to do CRUD operations in hierarchy grid - get the parent item from inside the child grid

@* If the data in the nested models is sufficient for your operations, you do not need the lambda functions *@

<TelerikGrid Data="@GridData"
             Pageable="true"
             PageSize="10"
             Sortable="true"
             EditMode="GridEditMode.Popup"
             OnUpdate="UpdateProduct"
             OnDelete="DeleteProduct"
             OnCreate="CreateProduct">
    <GridToolBar>
        <GridCommandButton Command="Add" Icon="add">Add Product</GridCommandButton>
    </GridToolBar>
    <GridColumns>
        <GridColumn Field=@nameof(Product.ProductName) Title="Product Name" />
        <GridColumn Field=@nameof(Product.UnitPrice) Title="Unit Price" />
        <GridColumn Field=@nameof(Product.UnitsInStock) Title="Units in stock" />
        <GridColumn Field=@nameof(Product.CreatedAt) Title="Date created" />
        <GridColumn Field=@nameof(Product.Discontinued) Title="Discontinued" Width="150px" />
        <GridCommandColumn Width="auto">
            <GridCommandButton Command="Edit" Icon="edit">Edit</GridCommandButton>
            <GridCommandButton Command="Delete" Icon="delete">Delete</GridCommandButton>
        </GridCommandColumn>
    </GridColumns>
    <DetailTemplate>
        @{
            Product product = context as Product;

            <TelerikGrid Data="@product.OrderDetails"
                         Height="auto"
                         Pageable="true"
                         Sortable="true"
                         PageSize="5"
                         EditMode="GridEditMode.Popup"
                         OnUpdate="@((GridCommandEventArgs args) => UpdateOrder(product, args))"
                         OnDelete="@((GridCommandEventArgs args) => DeleteOrder(args, product))"
                         OnCreate="@((GridCommandEventArgs args) => CreateOrder(args, product))">
                <GridToolBar>
                    <GridCommandButton Command="Add" Icon="add">Add Order</GridCommandButton>
                </GridToolBar>
                <GridColumns>
                    <GridColumn Field=@nameof(OrderDetails.OrderId) Title="Order ID" Editable="false" />
                    <GridColumn Field=@nameof(OrderDetails.UnitPrice) Title="Price" />
                    <GridColumn Field=@nameof(OrderDetails.Discount) Title="Discount">
                        <Template Context="order">
                            @(String.Format("{0:0.00}%", (order as OrderDetails).Discount))
                        </Template>
                    </GridColumn>
                    <GridColumn Field=@nameof(OrderDetails.Quantity) Title="Quantity" />
                    <GridCommandColumn Width="auto">
                        <GridCommandButton Command="Edit" Icon="edit">Edit</GridCommandButton>
                        <GridCommandButton Command="Delete" Icon="delete">Delete</GridCommandButton>
                    </GridCommandColumn>
                </GridColumns>
            </TelerikGrid>
        }
    </DetailTemplate>
</TelerikGrid>

@code {
    //CUD operations for the main Grid
    #region CUD operation for the main Grid
    private void UpdateProduct(GridCommandEventArgs args)
    {
        // perform actual data source operations here through your service

        var item = args.Item as Product;
        var index = GridData.FindIndex(x => x.ProductId == item.ProductId);
        if (index != -1)
        {
            GridData[index] = item;
        }
    }
    private void CreateProduct(GridCommandEventArgs args)
    {
        // perform actual data source operations here through your service

        var item = args.Item as Product;

        item.ProductId = GridData.Count + 1;

        GridData.Insert(0, item);
        item.OrderDetails = GenerateOrderDetails(item);
    }

    private void DeleteProduct(GridCommandEventArgs args)
    {
        // perform actual data source operations here through your service

        var item = args.Item as Product;

        GridData.Remove(item);
    }
    #endregion

    //CUD operations for the nested Grid
    #region CUD operations for the nested Grid
    private void UpdateOrder(Product product, GridCommandEventArgs args)
    {
        // perform actual data source operations here through your service

        var item = args.Item as OrderDetails;
        var data = product.OrderDetails;
        int index = data.FindIndex(x => x.OrderId == item.OrderId);
        if (index != -1)
        {
            data[index] = item;
        }
    }

    private void CreateOrder(GridCommandEventArgs args, Product product)
    {
        // perform actual data source operations here through your service

        var item = args.Item as OrderDetails;
        var data = product.OrderDetails;

        item.OrderId = data.Count + 1;

        data.Insert(0, item);
    }

    private void DeleteOrder(GridCommandEventArgs args, Product product)
    {
        // perform actual data source operations here through your service

        var item = args.Item as OrderDetails;
        var data = product.OrderDetails;

        data.Remove(item);
    }
    #endregion

    public List<Product> GridData { get; set; }
    DateTime StartDate = new DateTime(2018, 1, 1);
    static Random RandomGenerator = new Random();

    //Sample data and models
    #region Sample data and models
    protected override void OnInitialized()
    {
        GridData = GenerateProducts();
    }

    private List<Product> GenerateProducts()
    {
        List<Product> products = new List<Product>();

        for (int i = 1; i <= 100; i++)
        {
            var product = new Product()
            {
                ProductId = i,
                ProductName = "Product " + i.ToString(),
                SupplierId = i,
                UnitPrice = (decimal)(i * 3.14),
                UnitsInStock = (short)(i * 1),
                Discontinued = RandomGenerator.NextDouble() >= 0.5,
                CreatedAt = GetRandomDate(StartDate)
            };

            product.OrderDetails = GenerateOrderDetails(product);

            products.Add(product);
        }

        return products;
    }

    private List<OrderDetails> GenerateOrderDetails(Product product)
    {
        double minDiscount = 0.1;
        double maxDiscount = 0.2;
        var orderDetails = new List<OrderDetails>();

        for (int i = 1; i <= 40; i++)
        {
            orderDetails.Add(new OrderDetails()
            {
                OrderId = Int32.Parse($"{product.ProductId}{i}"),
                UnitPrice = (decimal)product.UnitPrice,
                Quantity = (short)(1 + (RandomGenerator.Next() % 10)),
                Discount = (float)((RandomGenerator.NextDouble() * (maxDiscount - minDiscount) + minDiscount)) * 100,
                ProductId = product.ProductId,
            });
        }

        return orderDetails;
    }

    private DateTime GetRandomDate(DateTime startDate)
    {
        int range = (DateTime.Today - startDate).Days;
        return startDate.AddDays(RandomGenerator.Next(range));
    }

    public class Product
    {
        public int ProductId { get; set; }
        public string ProductName { get; set; }
        public int SupplierId { get; set; }
        public decimal UnitPrice { get; set; }
        public short UnitsInStock { get; set; }
        public bool Discontinued { get; set; }
        public DateTime CreatedAt { get; set; }
        public List<OrderDetails> OrderDetails { get; set; }
    }

    public class OrderDetails
    {
        public int OrderId { get; set; }
        public decimal UnitPrice { get; set; }
        public short Quantity { get; set; }
        public float Discount { get; set; }
        public int ProductId { get; set; }
    }
    #endregion
}
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