svelte-kit-vice/src/uix/morfo/components/feed.ts

import type { Morfo } from '../types';
import { v } from '../types';

export const feedMorfo = {
	name: 'Feed',
	kebab: 'feed',
	scope: ['soma', 'sema'],
	expression: "family-default",
	apg: 'https://www.w3.org/WAI/ARIA/apg/patterns/feed/',
	texts: {
		label: '#?components.feed.label|Feed'
	},
	events: [
		{
			// User asked for more items (infinite scroll trigger / load-more
			// button). Soma owns whether/when to actually fetch. Per book
			// cap. 23 `commit.submit` — user submitted their request. The
			// actual fetch is downstream (sustain.processing →
			// commit.complete + affirm or commit.fail + risk).
			name: 'commit-submit-load-more',
			semantic: {
				family: 'commit',
				verb: 'submit',
				target: v.partRef('provider'),
				intent: 'neutral',
				sequence: 'post'
			}
		},
		{
			// Item focused via keyboard navigation (j/k or Arrow keys).
			// Per book cap. 27 §5 `shift.navigate`.
			name: 'shift-navigate-focus-item',
			semantic: {
				family: 'shift',
				verb: 'navigate',
				target: v.partRef('article'),
				sequence: 'post'
			}
		}
	],
	parts: [
		{
			name: 'Provider',
			kebab: 'provider',
			archetype: 'provider',
			kind: 'public',
			defaultElement: 'section',
			role: 'feed',
			optional: false,
			data: [{ attr: 'data-busy', value: v.propRef('busy'), severity: 'optional' }],
			aria: [
				{
					attr: 'aria-label',
					value: v.propRef('ariaLabel'),
					severity: 'recommended'
				},
				{
					attr: 'aria-labelledby',
					value: v.propRef('ariaLabelledby'),
					condition: { when: 'prop-truthy', prop: 'ariaLabelledby' },
					severity: 'optional'
				},
				{
					attr: 'aria-busy',
					value: v.literal('true'),
					severity: 'optional',
					condition: { when: 'prop-truthy', prop: 'busy' }
				}
			],
			keyboard: [
				{ key: 'PageDown', action: 'next-item' },
				{ key: 'PageUp', action: 'prev-item' },
				{ key: 'Ctrl+Home', action: 'first-item' },
				{ key: 'Ctrl+End', action: 'last-item' }
			]
		},
		{
			name: 'Article',
			kebab: 'article',
			archetype: 'item',
			kind: 'public',
			defaultElement: 'article',
			role: 'article',
			optional: false,
			data: [
				{ attr: 'data-posinset', value: v.propRef('posinset'), emit: 'value' },
				{ attr: 'data-level', value: v.propRef('level'), emit: 'value' }
			],
			aria: [
				{ attr: 'aria-posinset', value: v.propRef('posinset') },
				{ attr: 'aria-setsize', value: v.propRef('setsize') },
				{
					attr: 'aria-labelledby',
					value: v.partRef('article-title'),
					condition: { when: 'part-present', part: 'article-title' },
					severity: 'recommended'
				},
				{
					attr: 'aria-describedby',
					value: v.partRef('article-description'),
					condition: { when: 'part-present', part: 'article-description' },
					severity: 'optional'
				}
			]
		},
		{
			name: 'ArticleTitle',
			kebab: 'article-title',
			archetype: 'title',
			kind: 'public',
			defaultElement: 'div',
			role: 'heading',
			optional: true,
			data: [],
			aria: [{ attr: 'aria-level', value: v.propRef('level') }]
		},
		{
			name: 'ArticleDescription',
			kebab: 'article-description',
			archetype: 'description',
			kind: 'public',
			defaultElement: 'div',
			optional: true,
			data: [],
			aria: []
		},
		{
			name: 'Thread',
			kebab: 'thread',
			kind: 'public',
			defaultElement: 'div',
			role: 'feed',
			optional: true,
			data: [{ attr: 'data-level', value: v.propRef('level'), emit: 'value' }],
			aria: [
				{
					attr: 'aria-labelledby',
					value: v.partRef('article-title'),
					condition: { when: 'part-present', part: 'article-title' },
					severity: 'optional'
				}
			]
		},
		{
			name: 'Sentinel',
			kebab: 'sentinel',
			kind: 'public',
			defaultElement: 'div',
			optional: true,
			data: [
				{ attr: 'data-intersecting', value: v.propRef('intersecting'), severity: 'optional' }
			],
			aria: [{ attr: 'aria-hidden', value: v.literal('true') }]
		}
	]
} as const satisfies Morfo;