Things the PHP library does

So far, it looks like the H5P (Editor) Server does the following things: (boxes indicate what currently support)

• stores and serves libraries / content types (actual persistence is done in the plugin)
• stores and serves content (actual persistence is done in the plugin)
  • (mostly supported) CRUD operations on contents (=content.json and parts of h5p.json)
  • manages file uploads (= images, video etc.)
• store user state (for continuing later)
• AJAX endpoint for the editor (see AJAX Endpoint)
• backend communication with the H5P hub (see Communication with the H5P Hub)
  • register the site
  • send usage statistics
  • get information about content types on the hub
  • download and install new content types / updates of content types on user request
• validation of packages (structural integrity and conformity of content and libraries)
• validation of content against library semantics (+ filter html to prevent cross-site-scripting (XSS) vulnerabilities.)
• manage and check editor tokens (to make sure you have access rights to a session)
• logging & statistics generation: e.g. use of libraries by author, view of embedded content etc. (see h5p-php-library:h5p-event-base.class.php for a list of events)
• alter library files, semantics (allows site admins to change libraries without hacking the actual files; very useful)
• allows downloading h5p packages ("exporting" content)
• provide embed option for content (as div and as iframe)
• support copy & paste in the editor
• admin site / functionality (settings? +library management (what libraries of which version are installed & used how often; add libraries manually, update content of a specific library version))
• (partly supported) check permissions of users (install libraries, download h5p package, embed h5p package, create restricted, update libraries, install recommended, copy h5p?)
• cache assets (aggregates all css and js files into two big files to decrease http requests; done in h5p-php-library:h5p-default-storage.class.php->cacheAssets(...))