Blazor Grid Templates Popup Form Template

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With the FormTemplate feature, you can customize the appearance and content of the create/edit Popup window of the Grid.

In this article:

Using the Popup Form Template
Specifics
Example

Declare the desired custom content inside the <FormTemplate> inner tag of the <GridPopupEditFormSettings>. For example, TelerikForm or EditForm.
The FormTemplate provides a context of type GridPopupEditFormTemplateContext. It contains a clone of the Grid data item in its Item property, and reveals if the user is adding a new item or editing an existing one through its IsNew boolean property. Cast context.Item to your model type, so you can pass it to the custom form.
(optional) Use the Context attribute of the <FormTemplate> tag to set the name of the context variable.

Specifics

When using the template, the default Popup form is replaced by the declared content within the FormTemplate tag. This introduces the following specifics:

The default Update and Cancel buttons are removed. This means that the OnUpdate and OnCancel events do not fire. To modify or cancel the update of a record, you need to include custom components to manage these actions.
The popup footer remains empty by design. You can either hide it or place your custom buttons in it.
The FormTemplate disables the built-in validation of the Grid. Implement a Form Validation instead.
The <GridPopupEditFormSettings> parameters do not apply to a custom TelerikForm that you may render inside the <FormTemplate> tag. Set the desired Form configurations such as Columns, Orientation, and more on the Form component.

Example

Using a FormTemplate to modify the Edit/Create Popup window.

@using System.ComponentModel.DataAnnotations
@using Telerik.DataSource
@using Telerik.DataSource.Extensions

<TelerikGrid @ref="@GridRef"
             OnRead="@OnGridRead"
             TItem="@Product"
             EditMode="@GridEditMode.Popup"
             OnDelete="@OnGridDelete">
    <GridToolBarTemplate>
        <GridCommandButton Command="Add">Add Item</GridCommandButton>
    </GridToolBarTemplate>
    <GridSettings>
        <GridPopupEditSettings Width="550px" MaxHeight="95vh" MaxWidth="95vw"></GridPopupEditSettings>
        <GridPopupEditFormSettings Context="formContext">
            <FormTemplate>
                @{
                    if (GridEditItem is null)
                    {
                        // Setting GridEditItem unconditionally may
                        // reset the modified and unsaved values after re-render.
                        // Nullify GridEditItem when editing completes.
                        GridEditItem = (Product)formContext.Item;
                    }

                    <TelerikForm Model="@GridEditItem"
                                 ColumnSpacing="20px"
                                 Columns="2"
                                 ButtonsLayout="@FormButtonsLayout.Stretch"
                                 OnValidSubmit="@OnFormValidSubmit">
                        <FormItems>
                            <FormItem Field="@nameof(Product.Id)" Enabled="false" />
                            <FormItem Field="@nameof(Product.Name)" />
                            <FormItem Field="@nameof(Product.Description)"
                                      ColSpan="2"
                                      EditorType="@FormEditorType.TextArea" />
                            <FormItem Field="@nameof(Product.Price)">
                                <Template>
                                    <label class="k-label k-form-label">Price</label>
                                    <div class="k-form-field-wrap">
                                        <TelerikNumericTextBox @bind-Value="@GridEditItem.Price"
                                                               DebounceDelay="0" />
                                        <TelerikValidationMessage For="@( () => GridEditItem.Price)" />
                                    </div>
                                </Template>
                            </FormItem>
                            <FormItem Field="@nameof(Product.Quantity)" />
                            <FormItem Field="@nameof(Product.ReleaseDate)" />
                            <FormItem Field="@nameof(Product.Discontinued)" />
                        </FormItems>
                        <FormButtons>
                            <TelerikButton Icon="@nameof(SvgIcon.Save)">Save</TelerikButton>
                            <TelerikButton Icon="@nameof(SvgIcon.Cancel)"
                                           ButtonType="@ButtonType.Button"
                                           OnClick="@ExitGridEditMode">Cancel</TelerikButton>
                        </FormButtons>
                    </TelerikForm>
                }
            </FormTemplate>
        </GridPopupEditFormSettings>
    </GridSettings>
    <GridColumns>
        <GridColumn Field="@nameof(Product.Name)" />
        <GridColumn Field="@nameof(Product.Price)" DisplayFormat="{0:C2}" />
        <GridColumn Field="@nameof(Product.Quantity)" DisplayFormat="{0:N0}" />
        <GridColumn Field="@nameof(Product.ReleaseDate)" DisplayFormat="{0:d}" />
        <GridColumn Field="@nameof(Product.Discontinued)" Width="120px" />
        <GridCommandColumn Width="180px">
            <GridCommandButton Command="Edit">Edit</GridCommandButton>
            <GridCommandButton Command="Delete">Delete</GridCommandButton>
        </GridCommandColumn>
    </GridColumns>
</TelerikGrid>

@code {
    private ProductService GridProductService { get; set; } = new();

    private TelerikGrid<Product>? GridRef { get; set; }

    private Product? GridEditItem { get; set; }

    private async Task OnFormValidSubmit()
    {
        if (GridEditItem is null)
        {
            return;
        }

        if (GridEditItem.Id != default)
        {
            await GridProductService.Update(GridEditItem);
        }
        else
        {
            await GridProductService.Create(GridEditItem);
        }

        await ExitGridEditMode();
    }

    private async Task ExitGridEditMode()
    {
        if (GridRef is null)
        {
            return;
        }

        var state = GridRef.GetState();
        state.OriginalEditItem = null!;
        state.EditItem = null!;
        state.InsertedItem = null!;

        await GridRef.SetStateAsync(state);

        GridEditItem = default;
    }

    private async Task OnGridDelete(GridCommandEventArgs args)
    {
        var deletedItem = (Product)args.Item;

        await GridProductService.Delete(deletedItem);
    }

    private async Task OnGridRead(GridReadEventArgs args)
    {
        DataSourceResult result = await GridProductService.Read(args.Request);

        args.Data = result.Data;
        args.Total = result.Total;
        args.AggregateResults = result.AggregateResults;
    }

    public class Product
    {
        public int Id { get; set; }
        [Required]
        public string Name { get; set; } = string.Empty;
        public string Description { get; set; } = string.Empty;
        public decimal? Price { get; set; }
        public int Quantity { get; set; }
        [Required]
        public DateTime? ReleaseDate { get; set; }
        public bool Discontinued { get; set; }
    }

    #region Data Service

    public class ProductService
    {
        private List<Product> Items { get; set; } = new();

        private int LastId { get; set; }

        public async Task<int> Create(Product product)
        {
            await SimulateAsyncOperation();

            product.Id = ++LastId;

            Items.Insert(0, product);

            return LastId;
        }

        public async Task<bool> Delete(Product product)
        {
            await SimulateAsyncOperation();

            if (Items.Contains(product))
            {
                Items.Remove(product);

                return true;
            }

            return false;
        }

        public async Task<List<Product>> Read()
        {
            await SimulateAsyncOperation();

            return Items;
        }

        public async Task<DataSourceResult> Read(DataSourceRequest request)
        {
            return await Items.ToDataSourceResultAsync(request);
        }

        public async Task<bool> Update(Product product)
        {
            await SimulateAsyncOperation();

            int originalItemIndex = Items.FindIndex(x => x.Id == product.Id);

            if (originalItemIndex != -1)
            {
                Items[originalItemIndex] = product;
                return true;
            }

            return false;
        }

        private async Task SimulateAsyncOperation()
        {
            await Task.Delay(100);
        }

        public ProductService(int itemCount = 5)
        {
            Random rnd = Random.Shared;

            for (int i = 1; i <= itemCount; i++)
            {
                Items.Add(new Product()
                {
                    Id = ++LastId,
                    Name = $"Product {LastId}",
                    Description = $"Multi-line\ndescription {LastId}",
                    Price = LastId % 2 == 0 ? null : rnd.Next(0, 100) * 1.23m,
                    Quantity = LastId % 2 == 0 ? 0 : rnd.Next(0, 3000),
                    ReleaseDate = DateTime.Today.AddDays(-rnd.Next(365, 3650)),
                    Discontinued = LastId % 2 == 0
                });
            }
        }
    }

    #endregion Data Service
}

Popup Form Template

Using the Popup Form Template

Specifics

Example

See Also