doxa-maps/plugin-designs/pplr-data-maps/src/utils/pplrData.js

/**
 * pplrData.js — where this bundle's data files are served from.
 *
 * The maps were written against a page that served assets/data/ at the site root. Embedded, that
 * relative path resolves against the HOST page and 404s, so every fetch goes through dataUrl(),
 * which joins the tree's shared assets base (set once by the hub from resolveAssetsBase) with
 * pplr/<file>. The files are derived by ../scripts/build-data.mjs into data/pplr/.
 */
let base = './assets'
export function setDataBase(b) { if (b) base = String(b).replace(/\/+$/, '') }
export function dataUrl(file) { return base + '/pplr/' + file }

// d3 v7 is a page global here (as in the original build). Load it once, on first need.
let d3Promise = null
export function ensureD3() {
  if (typeof window === 'undefined' || window.d3) return Promise.resolve()
  if (!d3Promise) d3Promise = new Promise((res, rej) => {
    const s = document.createElement('script')
    s.src = 'https://cdn.jsdelivr.net/npm/d3@7/dist/d3.min.js'
    s.onload = () => res(); s.onerror = () => { d3Promise = null; rej(new Error('d3 failed to load')) }
    document.head.appendChild(s)
  })
  return d3Promise
}

// The 17 locale names per PG, split out of pg-points so the first paint stays small. Loaded on
// the first pin that opens a detail card.
let namesPromise = null
export function loadNames() {
  if (!namesPromise) namesPromise = fetch(dataUrl('pg-names.json'))
    .then((r) => { if (!r.ok) throw new Error('pg-names.json ' + r.status); return r.json() })
    .catch((e) => { namesPromise = null; throw e })
  return namesPromise
}

// The geocoder is a page global too (the original page carried a <script> tag). Load it once, on
// first need, and pick it BY ENGINE, as library/components/map-controls/GeocoderComponent.vue does:
// the Mapbox plugin under provider=mapbox, MapLibre's under provider=maplibre. A hard-coded Mapbox
// script made this the only request to api.mapbox.com in the keyless (maplibre) gallery.
export const GEOCODER = {
  mapbox:   { js: 'https://api.mapbox.com/mapbox-gl-js/plugins/mapbox-gl-geocoder/v5.0.0/mapbox-gl-geocoder.min.js',
              css: 'https://api.mapbox.com/mapbox-gl-js/plugins/mapbox-gl-geocoder/v5.0.0/mapbox-gl-geocoder.css',
              global: 'MapboxGeocoder' },
  maplibre: { js: 'https://cdn.jsdelivr.net/npm/@maplibre/maplibre-gl-geocoder@1/dist/maplibre-gl-geocoder.min.js',
              css: 'https://cdn.jsdelivr.net/npm/@maplibre/maplibre-gl-geocoder@1/dist/maplibre-gl-geocoder.css',
              global: 'MaplibreGeocoder' },
}
const geocoderPromises = {}
export function ensureGeocoder(provider = 'mapbox') {
  const g = GEOCODER[provider] || GEOCODER.mapbox
  if (typeof window === 'undefined' || window[g.global]) return Promise.resolve()
  if (!geocoderPromises[provider]) geocoderPromises[provider] = new Promise((res, rej) => {
    const s = document.createElement('script')
    s.src = g.js
    s.onload = () => res(); s.onerror = () => { delete geocoderPromises[provider]; rej(new Error('geocoder failed to load')) }
    document.head.appendChild(s)
  })
  return geocoderPromises[provider]
}

// The engine namespace that built THIS map (Popup, Marker, NavigationControl…). The views were
// written against the Mapbox global; under provider=maplibre that global does not exist and a
// `new mapboxgl.Popup` throws on the first pin click.
export function glFor(map) {
  if (typeof window === 'undefined') return undefined
  const ml = window.maplibregl
  if (ml && map && ml.Map && map instanceof ml.Map) return ml
  return window.mapboxgl || ml
}

// Verification handle (the gospel-resources __grState contract): what the ACTIVE view's map
// actually did, so a check can assert "loaded" rather than inferring it from missing requests.
// window.__pplrMap() -> { engine, loaded, styleLayers, pplrLayers }
export function exposeMap(map) {
  if (typeof window === 'undefined' || !map) return
  let loaded = false
  map.once('load', () => { loaded = true })
  window.__pplrMap = () => {
    let layers = []
    try { layers = map.getStyle()?.layers || [] } catch (_) {}
    return {
      engine: window.maplibregl && window.maplibregl.Map && map instanceof window.maplibregl.Map ? 'maplibre' : 'mapbox',
      // 'load' may already have fired before this listener was attached; a loaded style says so too
      loaded: loaded || !!(map.isStyleLoaded && map.isStyleLoaded()),
      styleLayers: layers.length,
      // sources this bundle added (not the basemap's): proof the view's own data reached the map
      dataSources: (() => { try { return Object.keys(map.getStyle()?.sources || {}).filter((k) => !/^(composite|mapbox|openmaptiles|natural_earth|ne2_shaded|maplibre)/i.test(k)).length } catch (_) { return 0 } })(),
    }
  }
}