sirrow
953664ff1c
Bluesky renders no link card of its own. Its PDS never fetches the page behind a URL, so a post whose record has no app.bsky.embed.external shows the link as bare text; every client that shows a card builds it before posting. We only built one for YouTube, so every other link arrived on bluesky with nothing attached. preview.go now reads the Open Graph tags of an ordinary page and turns them into the same card: og:title and og:description, falling back to the twitter:* tags and then to <title> and meta description, with og:image fetched as the thumbnail. YouTube keeps its oEmbed path, which answers with the handful of fields a card needs rather than the megabyte of markup the watch page is. Only the head of a page is read, and parsing stops at <body>, since preview tags belong above it and a truncated page still yields what was read. Pages are decoded through x/net/html/charset rather than assumed to be UTF-8, which Japanese pages served as Shift_JIS are not. The thumbnail is resolved against the URL the body came from, so a relative og:image survives a redirect. Requests now name the bot in a User-Agent, which some sites want before serving preview tags at all. fetch grew a byte limit and now reports the media type and final URL its body came with, which is what the thumbnail needs to name and resolve itself. Checked against go.dev, Japanese Wikipedia and a YouTube video. Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
21 KiB
21 KiB