Social preview card about the document, not the product

[HMarzban]

Status: raw idea. We have to discuss it and shape a plan before we build anything.

cc @edsaperia, @HMarzban

The idea

Edward Saperia suggested that the social preview of a pad link should be about the document, not about the product. He also proposed a first step: take the first sentence of the document and make it fit the card.

suggestion: it would be nice if the social preview was about the document rather than about the product

maybe we can take the first sentence of the document and make it fit

What we have today

• The preview title is the Pad title.
• The preview description is the description the owner set. Without one, it is a fixed product sentence.
• The preview image is one fixed product card for every pad (/icons/og-card-1280x640.png).
• A Private pad, or a blocked viewer, puts no title or description in the server response.
• The tags render on the server from _app.tsx, because the document shell does not render on the server.

Options to discuss

Nothing here is decided.

1. Text only. Use the first sentence as the description when the owner set none. The image stays the product card.
2. Text on the card. Draw the Pad title and the first sentence on a generated image. A small docs.plus mark stays on it.
3. Both.

The Documents list already pulls a heading and the first lines from a stored pad for its grid preview (documentGridPreview.ts). That code is prior art for the extraction.

Open questions

• What counts as the first sentence? What if the first block is an image, a list, or a heading?
• How do we make it fit? Where do we cut, and how long is the text? How do we handle right-to-left and non-Latin scripts?
• Who controls it? The owner already has a description field. Should the first sentence only fill an empty description?
• Anyone can edit an open pad, so anyone can change its first sentence. That text then shows on other sites. Do we accept this, or do we need a guard?
• A Private pad must never show content. Should it show the generic card?
• Chat apps and social sites keep a preview for a while. How stale can a card be after an edit? Can we version the image URL?
• A new pad has no stored text until its first save. What does the first share show?
• Where does the extraction run, and do we cache it? Every crawl hits the pad page.
• How much docs.plus branding stays on the card?

Next step

Talk it through in this thread. When we pick an option, we open an issue for it.