Rask.Validation.DataAnnotations 0.20.0

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<img alt="Rask" src="https://raw.githubusercontent.com/pal-tamas/rask/main/assets/rask-logo.svg" width="280">

Live apps in C#. One codebase — server-rendered over WebSockets, client-side in the browser via WebAssembly, or a native iOS/Android app.

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Write components as plain C# classes. Return a tree of HTML from Render(). No .razor, no JSX, no JavaScript to write — and the same component code runs server-rendered with live WebSocket updates or fully client-side on WebAssembly.

[Route("/counter")]
public sealed class Counter : Component
{
    private int _count;

    protected override Component? Render() =>
    [
        H1()["Counter"],
        P()[$"Current count: {_count}"],
        Button(OnClick: () => _count++)["Click me"]
    ];
}

Install

Prerequisites: the .NET 10 SDK (dotnet --version ≥ 10.0); the wasm-tools workload (dotnet workload install wasm-tools) for the WASM templates, or ios android (dotnet workload install ios android) for the native template.

dotnet tool install -g Rask.Cli          # the rask CLI (scaffolding)
rask new MyApp                            # or: --template wasm | wasm-hosted | native

Or add to an existing project:

dotnet add package Rask.Server            # server-rendered over WebSockets
dotnet add package Rask.Wasm              # client-side WebAssembly
dotnet add package Rask.Wasm.Hosting      # host a published WASM bundle on ASP.NET
dotnet add package Rask.Native            # native iOS/Android app head (WebView hybrid, preview)
dotnet add package Rask.Bootstrap          # optional: typed Bootstrap 5.3 components
dotnet add package Rask.WebPush           # send Web Push notifications from the backend
dotnet add package Rask.Cqrs              # source-generated CQRS/mediator (queries, commands, notifications)

Why Rask

After 15+ years building full-stack .NET apps — WebForms, MVC, Angular and React over a C# API — I wanted the front end back in C# without .razor mixing markup and code. So Rask makes a component a plain C# class that returns a tree, runs the same code on Server or WASM, and treats the network as the bottleneck (a state change ships a minimal diff, not the page). It's a craft project built in the open, deep on Roslyn source generators and tree diffing.

• One component model, three hosts — the same C# component runs Server (live diff over WS), WASM, or a native iOS/Android app (Rask.Native, preview).
• Compile-time factories — a Roslyn generator emits Div(...), Counter(...), type-safe routes.
• Scoped CSS & JS — sibling Component.css/Component.js, content-addressed and cached.
• Routing, lifecycle, forms, validation, auth — batteries included, no JavaScript required.
• Toast messages — inject IToaster for transient messages that survive a client-side navigation.
• Tiny live updates — a minimal edit-op diff ships instead of the whole page.
• Slow-link aware — WASM boot shows download progress; a slow Server round-trip surfaces a pending bar.
• Optional typed Bootstrap — Rask.Bootstrap adds typed Bootstrap 5.3 factories (BsButton/BsCard/BsModal/…), layout primitives (BsContainer, the BsRow/BsCol responsive grid, and BsStack), IFormControl<T>-bound inputs including the zero-JS BsSelect/BsMultiSelect comboboxes (full keyboard/listbox a11y, opt-in Filter search, OptionGroup grouping, OptionDisabled per-option disable, and a multiselect SelectAll header), a typed BsIcon, typed utility classes, and a BsDataGrid<T> for list screens (typed columns, sorting, paging, footer totals, master-detail), with interactive components driven by the live runtime — no JavaScript. See docs/bootstrap.md.

Links

• 📖 Documentation · Getting started · Configuration · Observability · Accessibility
• 🚀 Live demo
• 💻 Source & README
• 🤖 AI assistant guide

Licensed under MIT.