| 1 | // The deck's shape over yjs: root names and the small set of accessors |
| 2 | // ops, layout and view share — core/src/schema.rs's "roots and lookups" |
| 3 | // and "JSON <-> yrs values" sections. Every accessor is as tolerant as |
| 4 | // the core's: a key holding the wrong kind of value reads as absent, a |
| 5 | // non-map entry in an array of maps is skipped, never trapped on. |
| 6 | import * as Y from 'yjs' |
| 7 | import { readText } from './schema.mjs' |
| 8 | |
| 9 | export const ROOT_META = 'meta' |
| 10 | export const ROOT_SLIDES = 'slides' |
| 11 | export const ROOT_ASSETS = 'assets' |
| 12 | |
| 13 | /** The three root types. */ |
| 14 | export function roots (doc) { |
| 15 | return { |
| 16 | meta: doc.getMap(ROOT_META), |
| 17 | slides: doc.getArray(ROOT_SLIDES), |
| 18 | assets: doc.getMap(ROOT_ASSETS) |
| 19 | } |
| 20 | } |
| 21 | |
| 22 | export function getString (map, key) { |
| 23 | const v = map.get(key) |
| 24 | return typeof v === 'string' ? v : null |
| 25 | } |
| 26 | |
| 27 | export function getNumber (map, key) { |
| 28 | const v = map.get(key) |
| 29 | if (typeof v === 'number') return v |
| 30 | if (typeof v === 'bigint') return Number(v) |
| 31 | return null |
| 32 | } |
| 33 | |
| 34 | export function getMap (map, key) { |
| 35 | const v = map.get(key) |
| 36 | return v instanceof Y.Map ? v : null |
| 37 | } |
| 38 | |
| 39 | export function getArray (map, key) { |
| 40 | const v = map.get(key) |
| 41 | return v instanceof Y.Array ? v : null |
| 42 | } |
| 43 | |
| 44 | export function getFragment (map, key) { |
| 45 | const v = map.get(key) |
| 46 | return v instanceof Y.XmlFragment && !(v instanceof Y.XmlElement) ? v : null |
| 47 | } |
| 48 | |
| 49 | /** The maps of an array of maps, in order, as [index, map] pairs. */ |
| 50 | export function mapsOf (array) { |
| 51 | const out = [] |
| 52 | array.forEach((v, i) => { if (v instanceof Y.Map) out.push([i, v]) }) |
| 53 | return out |
| 54 | } |
| 55 | |
| 56 | /** The map in array whose id is id, as [index, map], or null. */ |
| 57 | export function findById (array, id) { |
| 58 | return mapsOf(array).find(([, m]) => getString(m, 'id') === id) ?? null |
| 59 | } |
| 60 | |
| 61 | // --- reading order (schema.rs, "reading order"; spec §2.2, §2.3, |
| 62 | // rulings 18 and 21) --- |
| 63 | // |
| 64 | // Both of the document's ordered arrays — the deck's slides and a |
| 65 | // slide's blocks — are SETS; the reading order is the `order` key on |
| 66 | // each map in them, with array index as the tie-break and as the rank |
| 67 | // of an entry that carries none. Reordering by moving array entries |
| 68 | // means deleting a map and inserting a copy, and a peer's edit in |
| 69 | // flight against the original is lost on merge (codex 4, at both |
| 70 | // levels); writing a number onto the map it already is loses nothing. |
| 71 | |
| 72 | /** The rank an entry sorts by: its order when a finite number, else its array index. */ |
| 73 | function rank (index, m) { |
| 74 | const n = getNumber(m, 'order') |
| 75 | return n !== null && Number.isFinite(n) ? n : index |
| 76 | } |
| 77 | |
| 78 | /** The maps of an ordered array (slides, a slide's blocks) in reading order, as [arrayIndex, map] pairs. */ |
| 79 | export function orderedMaps (array) { |
| 80 | return mapsOf(array).sort((a, b) => (rank(a[0], a[1]) - rank(b[0], b[1])) || (a[0] - b[0])) |
| 81 | } |
| 82 | |
| 83 | /** Whether any entry in the array carries an explicit order. */ |
| 84 | export function hasExplicitOrder (array) { |
| 85 | return mapsOf(array).some(([, m]) => { const n = getNumber(m, 'order'); return n !== null && Number.isFinite(n) }) |
| 86 | } |
| 87 | |
| 88 | /** Writes order 0..n-1 onto maps in the order given. */ |
| 89 | export function renumber (maps) { |
| 90 | maps.forEach((m, k) => m.set('order', k)) |
| 91 | } |
| 92 | |
| 93 | /** A plain object: a shared type rendered by content, a plain value as is. */ |
| 94 | function isPlainObject (v) { |
| 95 | return v !== null && typeof v === 'object' && !Array.isArray(v) && !(v instanceof Y.AbstractType) |
| 96 | } |
| 97 | |
| 98 | /** `Some(json)` when the value is a map (shared or plain), else null. */ |
| 99 | export function getObject (map, key) { |
| 100 | const v = map.get(key) |
| 101 | if (v instanceof Y.Map) return mapToJSON(v) |
| 102 | if (isPlainObject(v)) return anyToJSON(v) |
| 103 | return null |
| 104 | } |
| 105 | |
| 106 | export function anyToJSON (v) { |
| 107 | if (v === undefined) return null |
| 108 | if (typeof v === 'bigint') return Number(v) |
| 109 | if (Array.isArray(v)) return v.map(anyToJSON) |
| 110 | if (v instanceof Uint8Array) return Array.from(v) |
| 111 | if (isPlainObject(v)) { |
| 112 | const out = {} |
| 113 | for (const k of Object.keys(v)) out[k] = anyToJSON(v[k]) |
| 114 | return out |
| 115 | } |
| 116 | return v |
| 117 | } |
| 118 | |
| 119 | /** |
| 120 | * Any value the document holds, as JSON: a map as an object, an array |
| 121 | * as an array, a text fragment as its paragraphs, a text as its string. |
| 122 | */ |
| 123 | export function outToJSON (v) { |
| 124 | if (v instanceof Y.Map) return mapToJSON(v) |
| 125 | if (v instanceof Y.Array) return v.toArray().map(outToJSON) |
| 126 | if (v instanceof Y.XmlElement) return v.toString() |
| 127 | if (v instanceof Y.XmlFragment) return readText(v) |
| 128 | if (v instanceof Y.Text) return v.toString() |
| 129 | if (v instanceof Y.AbstractType) return null |
| 130 | return anyToJSON(v) |
| 131 | } |
| 132 | |
| 133 | export function mapToJSON (map) { |
| 134 | const out = {} |
| 135 | map.forEach((v, k) => { out[k] = outToJSON(v) }) |
| 136 | return out |
| 137 | } |
| 138 | |
| 139 | /** A deep copy of a map ready to insert elsewhere (yrs's as_prelim). */ |
| 140 | export function cloneMap (map) { |
| 141 | return map.clone() |
| 142 | } |
| 143 | |
amadan