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Forms are the foundation of UIMF applications. A form consists of a Request class (input fields), a Response class (output fields), and a handler that processes the request.

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Basic Form Structure

Every UIMF form has three main components:
  1. Request class - Defines input fields that users will fill out
  2. Response class - Defines output fields that display results
  3. Form handler - Processes the request and returns a response

​
Creating Your First Form

1

Define the Request class

Create a class to hold your form’s input fields:
public class CreateUserRequest : IRequest<CreateUserResponse>
{
    [InputField(Label = "First name", OrderIndex = 1, Required = true)]
    public string? FirstName { get; set; }

    [InputField(Label = "Last name", OrderIndex = 2, Required = true)]
    public string? LastName { get; set; }

    [InputField(Label = "Email", OrderIndex = 3, Required = true)]
    public string? Email { get; set; }

    [InputField(Label = "Age", OrderIndex = 4)]
    public int? Age { get; set; }
}
The IRequest<TResponse> interface comes from MediatR and indicates this is a request that returns a response.
2

Define the Response class

Create a class to hold your form’s output fields:
public class CreateUserResponse : FormResponse
{
    [OutputField(Label = "User ID")]
    public int UserId { get; set; }

    [OutputField(Label = "Created at")]
    public DateTime CreatedAt { get; set; }

    [OutputField(Label = "Full name")]
    public string FullName { get; set; }
}
The FormResponse base class provides standard form response functionality.
3

Implement the form handler

Create a form handler by inheriting from Form<TRequest, TResponse>:
using UiMetadataFramework.Basic.Server;
using UiMetadataFramework.Core.Binding;

[Form(Id = "create-user", Label = "Create User", PostOnLoad = false)]
public class CreateUserForm : Form<CreateUserRequest, CreateUserResponse>
{
    protected override CreateUserResponse Handle(CreateUserRequest request)
    {
        // Your business logic here
        var userId = SaveUserToDatabase(request);

        return new CreateUserResponse
        {
            UserId = userId,
            CreatedAt = DateTime.UtcNow,
            FullName = $"{request.FirstName} {request.LastName}"
        };
    }

    private int SaveUserToDatabase(CreateUserRequest request)
    {
        // Database save logic
        return 123; // Return generated user ID
    }
}
4

Add the FormAttribute

The [Form] attribute configures how the form behaves:
[Form(
    Id = "create-user",              // Unique identifier
    Label = "Create User",            // Display name
    PostOnLoad = false,               // Don't auto-submit on load
    CloseOnPostIfModal = true         // Close modal after submit
)]
Key properties:
  • Id - Unique identifier for the form
  • Label - Display name shown to users
  • PostOnLoad - Auto-submit when loaded (useful for reports)
  • PostOnLoadValidation - Validate before auto-submitting
  • CloseOnPostIfModal - Close modal after successful submission

​
Async Form Handlers

For operations that require async/await, use AsyncForm<TRequest, TResponse>: 
using UiMetadataFramework.Basic.Server;
using System.Threading;
using System.Threading.Tasks;

[Form(Id = "create-user-async", Label = "Create User")]
public class CreateUserAsyncForm : AsyncForm<CreateUserRequest, CreateUserResponse>
{
    private readonly IUserService _userService;

    public CreateUserAsyncForm(IUserService userService)
    {
        _userService = userService;
    }

    public override async Task<CreateUserResponse> Handle(
        CreateUserRequest request,
        CancellationToken cancellationToken)
    {
        var userId = await _userService.CreateUserAsync(request, cancellationToken);

        return new CreateUserResponse
        {
            UserId = userId,
            CreatedAt = DateTime.UtcNow,
            FullName = $"{request.FirstName} {request.LastName}"
        };
    }
}

​
Field Validation

Add validation to input fields using the Required property: 
public class CreateUserRequest : IRequest<CreateUserResponse>
{
    // Required field - must have a value
    [InputField(Label = "Email", Required = true)]
    public string? Email { get; set; }

    // Optional field
    [InputField(Label = "Phone number", Required = false)]
    public string? PhoneNumber { get; set; }
}

​
Controlling Field Order

Use OrderIndex to control the order fields appear in the UI: 
public class CreateUserRequest : IRequest<CreateUserResponse>
{
    [InputField(Label = "First name", OrderIndex = 1)]
    public string? FirstName { get; set; }

    [InputField(Label = "Last name", OrderIndex = 2)]
    public string? LastName { get; set; }

    [InputField(Label = "Email", OrderIndex = 3)]
    public string? Email { get; set; }
}
Fields with lower OrderIndex values appear first.

​
Hidden Fields

Hide fields from the UI while still using them in your form logic: 
public class UpdateUserRequest : IRequest<UpdateUserResponse>
{
    // Hidden field - not shown in UI
    [InputField(Hidden = true)]
    public int UserId { get; set; }

    // Visible field
    [InputField(Label = "New email address")]
    public string? Email { get; set; }
}

​
Complete Example

Here’s a complete working example of a user registration form: 
using MediatR;
using UiMetadataFramework.Basic.Server;
using UiMetadataFramework.Core;
using UiMetadataFramework.Core.Binding;

// Request class
public class RegisterUserRequest : IRequest<RegisterUserResponse>
{
    [InputField(Label = "Username", OrderIndex = 1, Required = true)]
    public string? Username { get; set; }

    [InputField(Label = "Email", OrderIndex = 2, Required = true)]
    public string? Email { get; set; }

    [InputField(Label = "Password", OrderIndex = 3, Required = true)]
    public Password? Password { get; set; }

    [InputField(Label = "Age", OrderIndex = 4)]
    public int? Age { get; set; }

    [InputField(Label = "Newsletter", OrderIndex = 5)]
    public bool SubscribeToNewsletter { get; set; }
}

// Response class
public class RegisterUserResponse : FormResponse
{
    [OutputField(Label = "User ID")]
    public int UserId { get; set; }

    [OutputField(Label = "Registration date")]
    public DateTime RegisteredAt { get; set; }

    [OutputField(Label = "Welcome message")]
    public string WelcomeMessage { get; set; }
}

// Form handler
[Form(
    Id = "register-user",
    Label = "User Registration",
    PostOnLoad = false,
    CloseOnPostIfModal = true
)]
public class RegisterUserForm : Form<RegisterUserRequest, RegisterUserResponse>
{
    private readonly IUserRepository _userRepository;

    public RegisterUserForm(IUserRepository userRepository)
    {
        _userRepository = userRepository;
    }

    protected override RegisterUserResponse Handle(RegisterUserRequest request)
    {
        // Validate and create user
        var user = new User
        {
            Username = request.Username!,
            Email = request.Email!,
            Password = HashPassword(request.Password!.Value),
            Age = request.Age,
            SubscribedToNewsletter = request.SubscribeToNewsletter
        };

        var userId = _userRepository.Create(user);

        return new RegisterUserResponse
        {
            UserId = userId,
            RegisteredAt = DateTime.UtcNow,
            WelcomeMessage = $"Welcome, {request.Username}! Your account has been created."
        };
    }

    private string HashPassword(string password)
    {
        // Password hashing logic
        return password; // Simplified for example
    }
}

​
Next Steps

Input Components

Learn about different input field types

Output Components

Display data with output components

Event Handlers

Add interactivity with event handlers

Custom Properties

Extend forms with custom metadata

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