Game with independently caching levels

This ServiceWorker web app demo will be a game where each level is a different cache group.

You can go ahead and do this however you wish; a good example would be a 2D platformer based on levels. Each level could have it's own ServiceWorker cache, when a user is visiting the app levels are cached in separate caches (maybe the next 2/3 levels?) which will then be ready for them to load and play as soon as they complete the previous level.

More Information / Requirements

• User visited page that was cached in a ServiceWorker cache, the site decides to show them the cached data straight away for performance, then update with fresh data when/if it arrives.

• User visits game’s url

  • If first visit
    • Loading screen delivered (as normal html)
    • Assets for menu screens and non-level specific behaviour (physics engine etc) downloaded and cached
      • If any request fails, error message (not browser UI) shown to user
  • Menu screen shown (using cached assets)
  • Send versions of game logic / menus & each cached level to server, server returns items that are out of date
    • if fail, abort these steps
    • If game logic / menus are out of date
      • Fetch new assets
      • If any request fails, do not cache, abort these steps
      • Once all assets are fetched, cache’em
    • for each out of date level, delete from cache
  • For each undownloaded level (with priority to earlier levels)
    • Download some kind of manifest for level, containing version, level structure and additional assets required
    • Request any additional resources indicated by manifest
    • Once the manifest and all resources have downloaded, commit to cache
    • If any request fails, do not cache, fail silently

• User clicks “play”

  • Level select screen fetched from cache and shown
  • Download progress/success/failure of levels indicated
  • User clicks on level whose download has failed or in progress
    • See “Starting uncached level”
  • User clicks on cached level
    • See “Starting cached level”

• Starting uncached level

  • Show loading screen
  • Restart download if failed
  • Download level data & cache as specified earlier (see “For each undownloaded level”)
  • If succeed
    • See “Starting cached level”
  • Else
    • Show reason as error message

• Starting cached level

  • Load level from cache & begin having fun
  • On level complete
    • If next level cached
      • See “Starting cached level”
    • Else
      • See “Starting uncached level”

Special Requirement

In this demo we have a special requirement for those of you who want to do something extra: one of the levels should go through an 'update'. The expected behaviour is the user should only be able to play an 'updated' level when 100% of the level has been cached. Of course it will be difficult for us to replicate this, so please go through the experience and just document the results as a .md file!

Questions

If you have questions please ask them in the issues. Just start a new issue with your question.