0070. Stories as the flows of a diagram

Status: accepted (stories-player-and-stills change, 4 November 2026). Amends 0023 and 0024.

Context

On 4 November 2026 the owner asked for “scenes of animation” that tell several flows of one diagram, so that a reader sees each flow on the same drawing instead of a copy pasted elsewhere with one zone highlighted. The language already had it: a file may hold several story blocks for one diagram, and the canvas plays any of them (decision 0023). Three things were missing. The HTML player held one story per page (version: 2, one timeline), so a reader of a page could not pick a flow. A story could only be started in the text, so a person on the canvas wrote story … for … { scene … { } } by hand before the timeline offered anything. And the picture of a scene, the frame that goes into a slide or a document, was written one --at <time> at a time.

Decision

• Version 3 documents hold a list of stories. A story document carries stories, each with its id, title, description and timeline, in the order given, over views embedded once by diagram id; the document’s id, title and description are its first story’s, so a page of one story reads as before. storiesDocument builds it, leaves out a story whose views cannot be drawn and names it; none drawn gives no document. PLAYER_VERSION is 3, and the runtime reads versions 2 and 3: readPlayerDocument lifts a version 2 timeline into one story of one, so pages written before keep playing. An older runtime says a version 3 document is unreadable, as it does for version 1; a page that mixes fragments takes the runtime of its newest one.
• The Story picker belongs to the control bar. With more than one story the player shows a <select aria-label="Story"> before the scene picker. Picking a flow shows its first frame at 0 s, stopped (in the static view, its first scene’s final state), keeps the static view and the zoom, fills the scene picker, names the frame and the figure by the story, and announces “Story: