Page methods

TODO: Complete reference for all page methods.

Methods to document:

• show(player) — whether to show the page
• context(player) — data for the template
• fields(player) — dynamic form fields
• validate(player) — custom validation
• timeout(player) — page timeout in seconds
• timeout_reached(player) — called on timeout
• may_proceed(player) — whether player can advance
• before_once(player) — runs once before showing
• before_always_once(player) — runs once before (no cache)
• after_once(player) — runs once after submission
• after_always_once(player) — runs once after (no cache)
• jsvars(player) — variables passed to JavaScript

For each method: - When it's called - Parameters - Return value - Example usage