Popup Form Template

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

Using the Popup Form Template

1. Declare the desired custom content inside the <FormTemplate> inner tag of the <GridPopupEditFormSettings>. For example, TelerikForm or EditForm.
2. 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.
3. (optional) Use the Context attribute of the <FormTemplate> tag to set the name of the context variable.

Specifics

When using the template, the built-in popup form is replaced by the declared content in 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 or events to manage these actions.
• There are two ways to define custom Form buttons:
  • Use the Form <FormButtons> template.
  • Use the Grid <ButtonsTemplate>, which is empty by default when using a <FormTemplate>. Remove the duplicate built-in Form Submit button with an empty <FormButtons> template.
• If you leave the Grid popup footer (<ButtonsTemplate>) empty, it takes up space in the popup. You can remove this empty popup footer space with CSS.
• 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
}

See Also

• Grid Popup Buttons Template
• Live Demo: Grid Templates
• Live Demo: Grid Popup Edit Form Template
• Blazor Grid