signals.dart: Skill for Claude Code

Components

Jaspr uses a component-based architecture very similar to Flutter's widgets. Concepts like ui composition, architecture and state management are transferable.

• StatelessComponent: For components that don't need mutable state. You must override Component build(BuildContext context).
• StatefulComponent: For components with mutable state. Requires an associated State class. The state has lifecycle methods like initState() and dispose(). You must override Component build(BuildContext context) in the state class.
• InheritedComponent: For propagating context or state efficiently down the component tree.

Returning Components from build

Building UIs in Jaspr requires you to return a single Component from build().

• Rule 1: You MUST NOT use Iterable<Component> build(BuildContext context) sync*. This is legacy code.
• Rule 2: You MUST use dot-shorthands instead of capitalized component names for fragments, text, and empty nodes.
  • Use .fragment([...]) (Do NOT use Fragment([...]) or fragment([...])).
  • Use .text('...') (Do NOT use Text('...') or text('...')).
  • Use .empty() to return an empty space safely.

Example Usage:

import 'package:jaspr/jaspr.dart';
import 'package:jaspr/dom.dart';

class MyComponent extends StatelessComponent {
  const MyComponent({super.key});

  @override
  Component build(BuildContext context) {
    // 1. Return a single component (e.g. div)
    // 2. Use dot-shorthand (.text) instead of Text()
    return div(classes: 'my-class', [
      .text('Hello World'),
    ]);
  }
}

HTML Components

Jaspr provides typed components for standard HTML elements (e.g., div(), p(), a(), button()). To use these add the package:jaspr/dom.dart import.

All HTML components take standard named Key? key, String? id, String? classes, Styles? style, Map<String, String>? attributes and Map<String, void Function(Event)>? events parameters. Most HTML components take a positional List<Component> children parameter (except for self-closing tags like img, input, br, etc.).