Files
boris/api/services/articleMeta.ts
Gigi 76b9797c41 feat: add article tags and image alt text to OG metadata
- Add tags field to ArticleMetadata type (extracted from 't' tags)
- Add imageAlt field to ArticleMetadata type (uses title as fallback)
- Extract 't' tags from article events in fetchArticleMetadataViaRelays
- Generate multiple article:tag meta tags in HTML output
- Add og:image:alt meta tag for better accessibility

This improves SEO and social media previews by including
article categorization tags and image descriptions.
2025-11-07 19:39:02 +01:00

161 lines
5.0 KiB
TypeScript

import WebSocket from 'ws'
;(globalThis as unknown as { WebSocket?: typeof WebSocket }).WebSocket ??= WebSocket
import { RelayPool } from 'applesauce-relay'
import { nip19 } from 'nostr-tools'
import { AddressPointer } from 'nostr-tools/nip19'
import { NostrEvent, Filter } from 'nostr-tools'
import { Helpers } from 'applesauce-core'
import { extractProfileDisplayName } from '../../lib/profile.js'
import { RELAYS } from '../../src/config/relays.js'
import type { ArticleMetadata } from './ogStore.js'
const { getArticleTitle, getArticleImage, getArticleSummary } = Helpers
async function fetchEventsFromRelays(
relayPool: RelayPool,
relayUrls: string[],
filter: Filter,
timeoutMs: number
): Promise<NostrEvent[]> {
const events: NostrEvent[] = []
await new Promise<void>((resolve) => {
const timeout = setTimeout(() => resolve(), timeoutMs)
relayPool.request(relayUrls, filter).subscribe({
next: (event) => {
events.push(event)
},
error: () => resolve(),
complete: () => {
clearTimeout(timeout)
resolve()
}
})
})
return events.sort((a, b) => b.created_at - a.created_at)
}
export async function fetchArticleMetadataViaRelays(naddr: string): Promise<ArticleMetadata | null> {
const relayPool = new RelayPool()
try {
const decoded = nip19.decode(naddr)
if (decoded.type !== 'naddr') {
return null
}
const pointer = decoded.data as AddressPointer
const relayUrls = pointer.relays && pointer.relays.length > 0 ? pointer.relays : RELAYS
const [articleEvents, profileEvents] = await Promise.all([
fetchEventsFromRelays(relayPool, relayUrls, {
kinds: [pointer.kind],
authors: [pointer.pubkey],
'#d': [pointer.identifier || '']
}, 7000),
fetchEventsFromRelays(relayPool, relayUrls, {
kinds: [0],
authors: [pointer.pubkey]
}, 5000)
])
if (articleEvents.length === 0) {
return null
}
const article = articleEvents[0]
const title = getArticleTitle(article) || 'Untitled Article'
const summary = getArticleSummary(article) || 'Read this article on Boris'
const image = getArticleImage(article) || '/boris-social-1200.png'
// Extract 't' tags (topic tags) from article event
const tags = article.tags
?.filter((tag) => tag[0] === 't' && tag[1])
.map((tag) => tag[1])
.filter((tag) => tag.length > 0) || []
// Generate image alt text (use title as fallback)
const imageAlt = title || 'Article cover image'
let authorName = pointer.pubkey.slice(0, 8) + '...'
if (profileEvents.length > 0) {
const displayName = extractProfileDisplayName(profileEvents[0])
if (displayName && !displayName.startsWith('@')) {
authorName = displayName
} else if (displayName) {
authorName = displayName.substring(1)
}
}
return {
title,
summary,
image,
author: authorName,
published: article.created_at,
tags: tags.length > 0 ? tags : undefined,
imageAlt
}
} catch (err) {
console.error('Failed to fetch article metadata via relays:', err)
return null
}
}
export async function fetchArticleMetadataViaGateway(naddr: string): Promise<ArticleMetadata | null> {
try {
const controller = new AbortController()
const timeout = setTimeout(() => controller.abort(), 2000)
const url = `https://njump.to/${naddr}`
console.log(`Fetching from gateway: ${url}`)
const resp = await fetch(url, {
redirect: 'follow',
signal: controller.signal
})
clearTimeout(timeout)
if (!resp.ok) {
console.error(`Gateway fetch failed: ${resp.status} ${resp.statusText} for ${url}`)
return null
}
const html = await resp.text()
console.log(`Gateway response length: ${html.length} chars`)
const pick = (re: RegExp) => {
const match = html.match(re)
return match?.[1] ? match[1].trim() : ''
}
const title = pick(/<meta[^>]+property=["']og:title["'][^>]+content=["']([^"']+)["']/i) ||
pick(/<title[^>]*>([^<]+)<\/title>/i)
const summary = pick(/<meta[^>]+property=["']og:description["'][^>]+content=["']([^"']+)["']/i)
const image = pick(/<meta[^>]+property=["']og:image["'][^>]+content=["']([^"']+)["']/i)
console.log(`Parsed from gateway - title: ${title ? 'found' : 'missing'}, summary: ${summary ? 'found' : 'missing'}, image: ${image ? 'found' : 'missing'}`)
if (!title && !summary && !image) {
console.log('No OG metadata found in gateway response')
return null
}
return {
title: title || 'Read on Boris',
summary: summary || 'Read this article on Boris',
image: image || '/boris-social-1200.png',
author: 'Boris'
}
} catch (err) {
console.error('Failed to fetch article metadata via gateway:', err)
if (err instanceof Error) {
console.error('Error details:', err.message, err.stack)
}
return null
}
}