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 cannot be triggered. To modify or cancel the update of a record, you need to include custom controls 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.Collections.Generic;
@using Telerik.DataSource
@using Telerik.DataSource.Extensions

<TelerikGrid @ref="@GridRef"
             Data="@GridData"
             EditMode="@GridEditMode.Popup"
             Pageable="true"
             Width="950px"
             PageSize="5"
             OnDelete="@DeleteItem">
    <GridToolBarTemplate>
        <GridCommandButton Command="Add" Icon="@SvgIcon.Plus">Add Employee</GridCommandButton>
    </GridToolBarTemplate>
    <GridSettings>
        <GridPopupEditSettings Width="550px" MaxHeight="95vh" MaxWidth="95vw"></GridPopupEditSettings>
        <GridPopupEditFormSettings Context="FormContext">
            <FormTemplate>
                @{
                    EditItem = FormContext.Item as Person;

                    <TelerikForm Model="@EditItem"
                                 ColumnSpacing="20px"
                                 Columns="2"
                                 ButtonsLayout="@FormButtonsLayout.Stretch"
                                 OnValidSubmit="@OnValidSubmit">
                        <FormItems>
                            <FormItem Field="EmployeeId" Enabled="false"></FormItem>
                            <FormItem Field="Name">
                            </FormItem>
                            <FormItem Field="HireDate" LabelText="Custom Hire Date Label"></FormItem>
                            <FormItem>
                                <Template>
                                    <label for="position">Custom Position Label</label>
                                    <TelerikDropDownList Data="@PositionsData"
                                                         @bind-Value="@EditItem.Position"
                                                         Id="position">
                                    </TelerikDropDownList>
                                </Template>
                            </FormItem>
                            </FormItems>
                            <FormButtons>
                                <TelerikButton Icon="@nameof(SvgIcon.Save)">Save</TelerikButton>
                                <TelerikButton Icon="@nameof(SvgIcon.Cancel)" ButtonType="@ButtonType.Button" OnClick="@OnCancel">Cancel</TelerikButton>
                            </FormButtons>
                        </TelerikForm>
                }
            </FormTemplate>
        </GridPopupEditFormSettings>
    </GridSettings>
    <GridColumns>
        <GridColumn Field=@nameof(Person.EmployeeId) Editable="false" />
        <GridColumn Field=@nameof(Person.Name) />
        <GridColumn Field=@nameof(Person.HireDate) Title="Hire Date" />
        <GridColumn Field=@nameof(Person.Position) Title="Position" />
        <GridCommandColumn>
            <GridCommandButton Command="Edit" Icon="@SvgIcon.Pencil">Edit</GridCommandButton>
            <GridCommandButton Command="Delete" Icon="@SvgIcon.Trash">Delete</GridCommandButton>
        </GridCommandColumn>
    </GridColumns>
</TelerikGrid>

@code {
    private List<string> PositionsData { get; set; } = new List<string>()
    {
        "Manager", "Developer", "QA"
    };

    private TelerikGrid<Person> GridRef { get; set; }
    private List<Person> GridData { get; set; }
    private Person EditItem { get; set; }
    private List<Person> _people;

    public class Person
    {
        public int EmployeeId { get; set; }
        public string Name { get; set; }
        public DateTime HireDate { get; set; }
        public string Position { get; set; }
    }

    public List<Person> People
    {
        get
        {
            if (_people == null)
            {
                _people = GeneratePeople(30);
            }

            return _people;
        }
    }

    protected override void OnInitialized()
    {
        LoadData();
    }

    private void LoadData()
    {
        GridData = GetPeople();
    }

    private void DeleteItem(GridCommandEventArgs args)
    {
        DeletePerson(args.Item as Person);

        LoadData();
    }

    private async Task OnValidSubmit()
    {

        if (EditItem.EmployeeId != default)
        {
            UpdatePerson(EditItem);
        }
        else
        {
            CreatePerson(EditItem);
        }

        await ExitEditAsync();

        LoadData();
    }

    private async Task OnCancel()
    {
        await ExitEditAsync();
    }

    private async Task ExitEditAsync()
    {
        var state = GridRef?.GetState();
        state.OriginalEditItem = null;
        state.EditItem = null;
        state.InsertedItem = null;

        await GridRef?.SetStateAsync(state);
    }

    #region Service Methods
    private List<Person> GetPeople()
    {
        return People;
    }

    private DataSourceResult GetPeople(DataSourceRequest request)
    {
        return People.ToDataSourceResult(request);
    }

    private void DeletePerson(Person person)
    {
        People.Remove(person);
    }

    private void UpdatePerson(Person person)
    {
        var index = People.FindIndex(i => i.EmployeeId == person.EmployeeId);
        if (index != -1)
        {
            People[index] = person;
        }
    }

    private void CreatePerson(Person person)
    {
        person.EmployeeId = People.Max(x => x.EmployeeId) + 1;

        People.Insert(0, person);
    }

    private List<Person> GeneratePeople(int count, int startIndex = 0)
    {
        List<Person> result = new List<Person>();

        for (int i = startIndex; i < startIndex + count; i++)
        {
            result.Add(new Person()
                {
                    EmployeeId = i,
                    Name = "Employee " + i.ToString(),
                    HireDate = new DateTime(2020, 6, 1).Date.AddDays(count - (i % 7)),
                    Position = i % 3 <= 2 ? PositionsData[i % 3] : PositionsData.FirstOrDefault()

                });
        }

        return result;
    }
    #endregion
}

Popup Form Template

Using the Popup Form Template

Specifics

Example

See Also