Linkability

This file has ideas only, so far. Comments welcome.

Scenarios

  • soduku app:
    • want to share the board layout, but not my progress so far
    • want to transfer my progress to another device
  • a wikipedia-like app:
    • follow links to other topics
    • have links from other apps (e.g. search) to a specific subsection of a topic
  • an instant-messenger app:
    • bookmark specific group conversations
  • a social network app:
    • link to specific posts
    • link to social network constructs like user lists (twitter), communities (g+), walls (fb), users…
  • an IDE
    • want to save a particular state of open windows, maybe to share with other developers
  • Navigation app
    • want to link to different modes of the app: nav mode, search page, personal profile, settings, etc
    • want to link to specific points of interest, either public (restaurant) or private (home, work, saved locations)
    • want to link to a specific map location, zoom level, direction, angle, time of day (for shadows), route (for navigation)
    • want to link to a destination in nav mode (without a route)
  • Podcast app
    • want to link to a specific view (e.g. in doggcatcher, feeds, audio, video, news...)
    • want to link to a specific podcast (maybe independently of the app)
    • want to link to a specific time in a specific episode of a specific podcast
    • save ui state (e.g. size of ui area vs podcast list in doggcatcher, scroll position in a list, specific settings window being on top of specific tab at a specific scroll position, etc)
  • News app
    • categories
    • articles
    • sets of categories
    • sets of categories + a selected category + a scroll position
    • app sections (e.g. Newsstand’s Explore vs Read Now vs My Library)
    • specific settings in the settings section of the app
  • Code Review Tools
    • a specific code review
    • a specific file in a specific code review
    • code review plus scroll position
    • specific comment
    • the state of the UI, such as which changes are visible, which comments are expanded, sort settings, filter settings, etc; whether the settings window is open, what tab it’s open to, what field is focused…

UI

  • Sharing current state to another device using NFC: just put the phones together, the active app(s?) serialise their state to a “URL” and that is sent to the other device
  • App exposes a “permalink” or “get link” UI that exposes a string you can Share (a la Android’s Share intent) or copy and paste.
  • An accessibility tree should expose the URL of each part of the app so that a user with an accessibility tool can bookmark a particular location in the app to jump to it later.

Thoughts

  • Seems like you link to three kinds of things:
    • different in-app concepts, which might be shared across apps
      • specific posts in a social network
      • users
      • particular game board starting configurations, game levels
      • wikipedia topics
      • search results
      • POIs in a map
      • videos on Vimeo, YouTube, etc
      • a code review / CL / pull request
      • a comment on a code review
      • a file in a code review
      • a comment in a blog post
      • telephone numbers
      • lat/long coordinates
      • podcasts
    • different top-level parts of the app (shallow state)
      • e.g. in Facebook, linking to the stream; in G+, linking to the communities landing page, etc
      • in a maps app, the mode (satellite, navigation, etc)
    • deep state
      • the current state of a particular game board, e.g. all the piece positions in chess, all the current choices in soduku...
      • what windows are open, what field is focused, what widgets are expanded, the precise view of a 3D map, etc
      • subsection of a topic in wikipedia (scroll position)
  • Since almost every app is going to have app-specific items, we need to make the item space trivially extensible (no registry, no fixed vocabulary). This means that common items (e.g. lat/long coordinates, podcasts) will probably evolve conventions organically within communities rather than in a centralised fashion
  • We don’t have to use URLs as they are known today, but doing so would leverage the existing infrastructure which might be valuable

Ideas

  • Two kinds of URLs: application state, and “things”.
  • Application state URLs consist of an identifier for the app, plus a blob of data for how to open the app
  • Thing URLs identify a thing, either by string name, opaque identifier, or more structured data (e.g. two comma-separated floating point numbers for lat/long).
  • Thing URLs have a label saying what they are, e.g. “poi” or “geo” or “cl-comment” or something.
  • Maybe “apps” are just things, and going to an app is like picking that app thing from the system app, the same way you’d pick a post from a social network app.