FormKit.Abstractions 1.7.0

FormKit

A lightweight, fluent form builder for Blazor that generates accessible EditForm markup, validation wiring, and field components from a strongly-typed model. Renderer-agnostic: the same fluent definition works with plain HTML, MudBlazor, or FluentUI via swappable renderers.

Quickstart

1. Install

dotnet add package FormKit
dotnet add package FormKit.Renderers.Html

2. Register services

builder.Services.AddFormKit()
    .UseHtmlRenderer();

3. Define and render a form

@page "/customers/new"
@using FormKit

<FormKitForm TModel="CustomerVm"
             Definition="@_form"
             Model="@_model"
             OnValidSubmit="HandleSubmit" />

@code {
    private CustomerVm _model = new();

    private readonly FormDefinition<CustomerVm> _form = FormBuilder.For<CustomerVm>()
        .Field(x => x.Name).Required().MaxLength(120)
        .Field(x => x.Email).Required()
        .Field(x => x.IsCompany).Label("Is a company")
        .Field(x => x.CompanyName)
            .When(m => m.IsCompany)
            .Required()
        .Group("Address", g => g
            .Field(x => x.Address.Street).Required()
            .Field(x => x.Address.City).Required()
            .Field(x => x.Address.Country).Select<Country>())
        .Build();

    private Task HandleSubmit(EditContext context) => _service.CreateAsync(_model);
}

Features

• Fluent API — describe forms from POCO models in a few lines
• Accessible by default — correct label/for association, aria-required, aria-invalid, aria-describedby, role="alert" error regions
• Conditional fields — .When(m => m.IsCompany) shows/hides fields based on model state
• Multi-step forms — .Step("Customer", ...) with per-step validation
• Field groups — .Group("Address", ...) renders as <fieldset> with <legend>
• DataAnnotations validation — built-in via EditForm and DataAnnotationsValidator
• Pluggable renderers — swap UI libraries without rewriting form definitions
• Trimming & AOT friendly — annotated with IsTrimmable=true

Supported Field Types

Architecture

A live demo (Blazor WebAssembly, with an HTML/FluentUI renderer toggle) is published to GitHub Pages: https://agriffard.github.io/FormKit/.

License

MIT