DxGrid.CustomizeEditModel Event

Allows you to create a custom edit model or customize an automatically-generated edit model.

Namespace: DevExpress.Blazor

Assembly: DevExpress.Blazor.v21.2.dll

NuGet Package: DevExpress.Blazor

Declaration

[Parameter]
public EventCallback<GridCustomizeEditModelEventArgs> CustomizeEditModel { get; set; }

Parameters

Type	Description
GridCustomizeEditModelEventArgs	A GridCustomizeEditModelEventArgs object that contains data for this event.

Remarks

The Grid allows users to edit its data either by using the edit form or by showing the edit form in a pop-up window.

Tip

For information on how to enable data editing and use edit-related options, refer to the following topic: Edit Data and Validate Input.

The Grid tries to create an edit model based on a bound data item. Handle the CustomizeEditModel event to implement your own edit model or customize an automatically-generated edit model.

Run Demo: Grid - Edit Data

Create a Custom Edit Model

The Grid cannot generate an edit model in the following cases:

• A data item class does not have a parameterless constructor.
• Data item fields bound to Grid columns are read-only.

Follow the steps below to implement a custom edit model.

1. Declare an edit model class and its fields.
2. Handle the CustomizeEditModel event.
3. Use the event argument’s DataItem property to access a data item. If this property is set to null, the edit model corresponds to a new row.
4. Assign your custom edit model to the event argument’s EditModel property.
5. In the EditModelSaving event handler and the EditFormTemplate, cast the EditModel property value to your custom edit model class.

Razor

@using Microsoft.EntityFrameworkCore
@inject IDbContextFactory<NorthwindContext> NorthwindContextFactory
@implements IDisposable
@using System.ComponentModel.DataAnnotations;

<DxGrid Data="GridDataSource"
        EditModelSaving="OnEditModelSaving"
        DataItemDeleting="OnDataItemDeleting"
        KeyFieldName="EmployeeId"
        CustomizeEditModel="Grid_CustomizeEditModel">
    <Columns>
        <DxGridCommandColumn />
        <DxGridDataColumn FieldName="FirstName" />
        <DxGridDataColumn FieldName="LastName" />
        <DxGridDataColumn FieldName="Title" />
        <DxGridDataColumn FieldName="HireDate" />
    </Columns>
    <EditFormTemplate Context="editFormContext">
        @{
            var employee = (EmployeeEditModel)editFormContext.EditModel;
        }
        <DxFormLayout>
            <DxFormLayoutItem Caption="First Name:">
                <DxTextBox @bind-Text="@employee.FirstName" />
            </DxFormLayoutItem>
            <DxFormLayoutItem Caption="Last Name:">
                <DxTextBox @bind-Text="@employee.LastName" />
            </DxFormLayoutItem>
            <DxFormLayoutItem Caption="Title:">
                <DxTextBox @bind-Text="@employee.Title" />
            </DxFormLayoutItem>
            <DxFormLayoutItem Caption="Hire Date:">
                <DxDateEdit @bind-Date="@employee.HireDate" />
            </DxFormLayoutItem>
        </DxFormLayout>
    </EditFormTemplate>
</DxGrid>

@code {
    IEnumerable<object> GridDataSource { get; set; }
    NorthwindContext Northwind { get; set; }

    protected override async Task OnInitializedAsync() {
        Northwind = NorthwindContextFactory.CreateDbContext();
        GridDataSource = await Northwind.Employees.ToListAsync();
    }

    class EmployeeEditModel {
        public int? EmployeeId { get; set; }
        [Required, MaxLength(64)]
        public string LastName { get; set; }
        [Required, MaxLength(64)]
        public string FirstName { get; set; }
        public string Title { get; set; }
        public DateTime? HireDate { get; set; }
    }

    async Task OnEditModelSaving(GridEditModelSavingEventArgs e) {
        var editModel = (EmployeeEditModel)e.EditModel;
        // Re-query a data item from the database.
        var dataItem = e.IsNew ? new Employee() : Northwind.Employees.Find(editModel.EmployeeId);
        // Assign changes from the edit model to the data item.
        if (dataItem != null) {
            dataItem.FirstName = editModel.FirstName;
            dataItem.LastName = editModel.LastName;
            dataItem.Title = editModel.Title;
            dataItem.HireDate = editModel.HireDate;
            // Post changes to the database.
            if (e.IsNew)
                await Northwind.AddAsync(dataItem);
            await Northwind.SaveChangesAsync();
            // Reload the entire Grid.
            GridDataSource = await Northwind.Employees.ToListAsync();
        }
    }

    async Task OnDataItemDeleting(GridDataItemDeletingEventArgs e) {
        // Re-query a data item from the database.
        var dataItem = Northwind.Employees.Find((e.DataItem as Employee).EmployeeId);
        if (dataItem != null) {
            // Remove the data item from the database.
            Northwind.Remove(dataItem);
            await Northwind.SaveChangesAsync();
            // Reload the entire Grid.
            GridDataSource = await Northwind.Employees.ToListAsync();
        }
    }

    async Task Grid_CustomizeEditModel(GridCustomizeEditModelEventArgs e) {
        var dataItem = (Employee)e.DataItem;
        if (dataItem == null)
            e.EditModel = new EmployeeEditModel { };
        else {
            e.EditModel = new EmployeeEditModel {
                EmployeeId = dataItem.EmployeeId,
                FirstName = dataItem.FirstName,
                LastName = dataItem.LastName,
                Title = dataItem.Title,
                HireDate = dataItem.HireDate
            };
        }
    }

    public void Dispose() {
        Northwind?.Dispose();
    }
}

Employee

using System;
using System.Collections.Generic;
using System.ComponentModel.DataAnnotations;

namespace Grid.Northwind {
    public partial class Employee {
        public int EmployeeId { get; set; }
        [Required]
        public string LastName { get; set; }
        [Required]
        public string FirstName { get; set; }
        [Required]
        public string Title { get; set; }
        public string TitleOfCourtesy { get; set; }
        public Nullable<System.DateTime> BirthDate { get; set; }
        [Required]
        [Range(typeof(DateTime), "1/1/2000", "1/1/2020",
        ErrorMessage = "HireDate must be between {1:d} and {2:d}")]
        public Nullable<System.DateTime> HireDate { get; set; }
        public string Address { get; set; }
        public string City { get; set; }
        public string Region { get; set; }
        public string PostalCode { get; set; }
        public string Country { get; set; }
        public string HomePhone { get; set; }
        public string Extension { get; set; }
        public byte[] Photo { get; set; }
        public string Notes { get; set; }
        public Nullable<int> ReportsTo { get; set; }
        public string PhotoPath { get; set; }
        public virtual ICollection<Order> Orders { get; set; }
        public string Text => $"{FirstName} {LastName} ({Title})";
        public string ImageFileName => $"Employees/{EmployeeId}.jpg";
    }
}

NorthwindContext

using Microsoft.EntityFrameworkCore;
#nullable disable

namespace Grid.Northwind {
    public partial class NorthwindContext : DbContext {

        public NorthwindContext(DbContextOptions<NorthwindContext> options)
            : base(options) {
        }
        // ...
        public virtual DbSet<Employee> Employees { get; set; }

        protected override void OnConfiguring(DbContextOptionsBuilder optionsBuilder) {
            if(!optionsBuilder.IsConfigured) {
                optionsBuilder.UseSqlServer("Server=.\\sqlexpress;Database=Northwind;Integrated Security=true");
            }
        }

        protected override void OnModelCreating(ModelBuilder modelBuilder) {
            modelBuilder.HasAnnotation("Relational:Collation", "SQL_Latin1_General_CP1_CI_AS");
            // ...
            modelBuilder.Entity<Employee>(entity => {
                entity.HasIndex(e => e.EmployeeId, "EmployeeId");
                entity.HasIndex(e => e.LastName, "LastName");
                entity.HasIndex(e => e.FirstName, "FirstName");
                entity.HasIndex(e => e.Title, "Title");
                entity.HasIndex(e => e.BirthDate, "BirthDate");
                entity.HasIndex(e => e.HireDate, "HireDate");
                entity.HasIndex(e => e.Notes, "Notes");
            });
            OnModelCreatingPartial(modelBuilder);
        }

        partial void OnModelCreatingPartial(ModelBuilder modelBuilder);
    }
}

Startup.cs (.NET 5.0)

using Microsoft.EntityFrameworkCore;
// ...
    public class Startup {
    // ...
        public void ConfigureServices(IServiceCollection services) {
        // ...
            services.AddDbContextFactory<NorthwindContext>((sp, options) => {
                var env = sp.GetRequiredService<IWebHostEnvironment>();
                var dbPath = Path.Combine(env.ContentRootPath, "Northwind-5e44b51f.mdf");
                options.UseSqlServer("Server=(localdb)\\MSSQLLocalDB;Integrated Security=true;AttachDbFileName=" + dbPath);
            });
        }
        // ...
    }

Program.cs (.NET 6.0)

using Microsoft.EntityFrameworkCore;
// ...
builder.Services.AddDbContextFactory<NorthwindContext>((sp, options) => {
    var env = sp.GetRequiredService<IWebHostEnvironment>();
    var dbPath = Path.Combine(env.ContentRootPath, "Northwind-5e44b51f.mdf");
    options.UseSqlServer("Server=(localdb)\\MSSQLLocalDB;Integrated Security=true;AttachDbFileName=" + dbPath);
});

Initialize New Rows

The CustomizeEditModel event allows you to display predefined values in data editors when a user adds a new row.

1. Check the event argument’s IsNew property to identify new rows.
2. Use the EditModel property to access the edit model and initialize model field values.

The following snippet specifies the predefined value for the HireDate field:

Razor

@using Microsoft.EntityFrameworkCore
@inject IDbContextFactory<NorthwindContext> NorthwindContextFactory
@implements IDisposable

<DxGrid Data="GridDataSource"
        EditModelSaving="OnEditModelSaving"
        DataItemDeleting="OnDataItemDeleting"
        KeyFieldName="EmployeeId"
        CustomizeEditModel="Grid_CustomizeEditModel">
    <Columns>
        <DxGridCommandColumn />
        <DxGridDataColumn FieldName="FirstName" />
        <DxGridDataColumn FieldName="LastName" />
        <DxGridDataColumn FieldName="Title" />
        <DxGridDataColumn FieldName="HireDate" />
    </Columns>
    <EditFormTemplate Context="editFormContext">
        @{
            var employee = (Employee)editFormContext.EditModel;
        }
        <DxFormLayout>
            <DxFormLayoutItem Caption="First Name:">
                <DxTextBox @bind-Text="@employee.FirstName" />
            </DxFormLayoutItem>
            <DxFormLayoutItem Caption="Last Name:">
                <DxTextBox @bind-Text="@employee.LastName" />
            </DxFormLayoutItem>
            <DxFormLayoutItem Caption="Title:">
                <DxTextBox @bind-Text="@employee.Title" />
            </DxFormLayoutItem>
            <DxFormLayoutItem Caption="Hire Date:">
                <DxDateEdit @bind-Date="@employee.HireDate" />
            </DxFormLayoutItem>
        </DxFormLayout>
    </EditFormTemplate>
</DxGrid>

@code {
    IEnumerable<object> GridDataSource { get; set; }
    NorthwindContext Northwind { get; set; }

    protected override async Task OnInitializedAsync() {
        Northwind = NorthwindContextFactory.CreateDbContext();
        GridDataSource = await Northwind.Employees.ToListAsync();
    }

    async Task OnEditModelSaving(GridEditModelSavingEventArgs e) {
        var editModel = (Employee)e.EditModel;
        // Re-query a data item from the database.
        var dataItem = e.IsNew ? new Employee() : Northwind.Employees.Find(editModel.EmployeeId);
        // Assign changes from the edit model to the data item.
        if (dataItem != null) {
            dataItem.FirstName = editModel.FirstName;
            dataItem.LastName = editModel.LastName;
            dataItem.Title = editModel.Title;
            dataItem.HireDate = editModel.HireDate;
            // Post changes to the database.
            if (e.IsNew)
                await Northwind.AddAsync(dataItem);
            await Northwind.SaveChangesAsync();
            // Reload the entire Grid.
            GridDataSource = await Northwind.Employees.ToListAsync();
        }
    }

    async Task OnDataItemDeleting(GridDataItemDeletingEventArgs e) {
        // Re-query a data item from the database.
        var dataItem = Northwind.Employees.Find((e.DataItem as Employee).EmployeeId);
        if (dataItem != null) {
            // Remove the data item from the database.
            Northwind.Remove(dataItem);
            await Northwind.SaveChangesAsync();
            // Reload the entire Grid.
            GridDataSource = await Northwind.Employees.ToListAsync();
        }
    }

    async Task Grid_CustomizeEditModel(GridCustomizeEditModelEventArgs e) {
        if (e.IsNew) {
            var editModel = (Employee)e.EditModel;
            editModel.HireDate = DateTime.Today;
        }
    }

    public void Dispose() {
        Northwind?.Dispose();
    }
}

Employee

using System;
using System.Collections.Generic;
using System.ComponentModel.DataAnnotations;

namespace Grid.Northwind {
    public partial class Employee {
        public int EmployeeId { get; set; }
        [Required]
        public string LastName { get; set; }
        [Required]
        public string FirstName { get; set; }
        [Required]
        public string Title { get; set; }
        public string TitleOfCourtesy { get; set; }
        public Nullable<System.DateTime> BirthDate { get; set; }
        [Required]
        [Range(typeof(DateTime), "1/1/2000", "1/1/2020",
        ErrorMessage = "HireDate must be between {1:d} and {2:d}")]
        public Nullable<System.DateTime> HireDate { get; set; }
        public string Address { get; set; }
        public string City { get; set; }
        public string Region { get; set; }
        public string PostalCode { get; set; }
        public string Country { get; set; }
        public string HomePhone { get; set; }
        public string Extension { get; set; }
        public byte[] Photo { get; set; }
        public string Notes { get; set; }
        public Nullable<int> ReportsTo { get; set; }
        public string PhotoPath { get; set; }
        public virtual ICollection<Order> Orders { get; set; }
        public string Text => $"{FirstName} {LastName} ({Title})";
        public string ImageFileName => $"Employees/{EmployeeId}.jpg";
    }
}

NorthwindContext

using Microsoft.EntityFrameworkCore;
#nullable disable

namespace Grid.Northwind {
    public partial class NorthwindContext : DbContext {

        public NorthwindContext(DbContextOptions<NorthwindContext> options)
            : base(options) {
        }
        // ...
        public virtual DbSet<Employee> Employees { get; set; }

        protected override void OnConfiguring(DbContextOptionsBuilder optionsBuilder) {
            if(!optionsBuilder.IsConfigured) {
                optionsBuilder.UseSqlServer("Server=.\\sqlexpress;Database=Northwind;Integrated Security=true");
            }
        }

        protected override void OnModelCreating(ModelBuilder modelBuilder) {
            modelBuilder.HasAnnotation("Relational:Collation", "SQL_Latin1_General_CP1_CI_AS");
            // ...
            modelBuilder.Entity<Employee>(entity => {
                entity.HasIndex(e => e.EmployeeId, "EmployeeId");
                entity.HasIndex(e => e.LastName, "LastName");
                entity.HasIndex(e => e.FirstName, "FirstName");
                entity.HasIndex(e => e.Title, "Title");
                entity.HasIndex(e => e.BirthDate, "BirthDate");
                entity.HasIndex(e => e.HireDate, "HireDate");
                entity.HasIndex(e => e.Notes, "Notes");
            });
            OnModelCreatingPartial(modelBuilder);
        }

        partial void OnModelCreatingPartial(ModelBuilder modelBuilder);
    }
}

Startup.cs (.NET 5.0)

using Microsoft.EntityFrameworkCore;
// ...
    public class Startup {
    // ...
        public void ConfigureServices(IServiceCollection services) {
        // ...
            services.AddDbContextFactory<NorthwindContext>((sp, options) => {
                var env = sp.GetRequiredService<IWebHostEnvironment>();
                var dbPath = Path.Combine(env.ContentRootPath, "Northwind-5e44b51f.mdf");
                options.UseSqlServer("Server=(localdb)\\MSSQLLocalDB;Integrated Security=true;AttachDbFileName=" + dbPath);
            });
        }
        // ...
    }

Program.cs (.NET 6.0)

using Microsoft.EntityFrameworkCore;
// ...
builder.Services.AddDbContextFactory<NorthwindContext>((sp, options) => {
    var env = sp.GetRequiredService<IWebHostEnvironment>();
    var dbPath = Path.Combine(env.ContentRootPath, "Northwind-5e44b51f.mdf");
    options.UseSqlServer("Server=(localdb)\\MSSQLLocalDB;Integrated Security=true;AttachDbFileName=" + dbPath);
});