lazyflat/web/static/map.js

// lazyflat — Leaflet flat map
// A single Leaflet map instance; re-initialised after every HTMX swap of
// the Wohnungen body. Also flushes size when the view toggle flips from
// list to map (Leaflet needs invalidateSize on a hidden-then-shown map).

let mapInstance = null;
const BERLIN_CENTER = [52.52, 13.405];
const BERLIN_ZOOM = 11;

function initFlatsMap() {
  const el = document.getElementById("flats-map");
  if (!el || typeof L === "undefined") return;
  if (mapInstance) {
    try { mapInstance.remove(); } catch (e) {}
    mapInstance = null;
  }
  mapInstance = L.map(el).setView(BERLIN_CENTER, BERLIN_ZOOM);
  L.tileLayer("https://{s}.tile.openstreetmap.org/{z}/{x}/{y}.png", {
    attribution: "© OpenStreetMap",
    maxZoom: 18,
  }).addTo(mapInstance);

  let data = [];
  try {
    data = JSON.parse(el.dataset.flats || "[]");
  } catch (e) {
    console.warn("flats-map: bad JSON in data-flats", e);
  }

  const bounds = [];
  data.forEach((f) => {
    if (typeof f.lat !== "number" || typeof f.lng !== "number") return;
    const m = L.marker([f.lat, f.lng]).addTo(mapInstance);
    const rent = f.rent ? Math.round(f.rent) + " €" : "";
    const rooms = f.rooms ? f.rooms + " Zi" : "";
    const size = f.size ? Math.round(f.size) + " m²" : "";
    const meta = [rooms, size, rent].filter(Boolean).join(" · ");
    const safeAddr = (f.address || "").replace(/</g, "&lt;");
    const safeLink = (f.link || "#").replace(/"/g, "&quot;");
    m.bindPopup(
      `<b>${safeAddr}</b>` +
        (meta ? `<br>${meta}` : "") +
        `<br><a href="${safeLink}" target="_blank" rel="noopener">Zur Anzeige →</a>`,
    );
    bounds.push([f.lat, f.lng]);
  });
  if (bounds.length === 1) {
    mapInstance.setView(bounds[0], 14);
  } else if (bounds.length > 1) {
    mapInstance.fitBounds(bounds, { padding: [30, 30] });
  }
}

function flushMapSize() {
  if (mapInstance) {
    setTimeout(() => mapInstance.invalidateSize(), 50);
  }
}

function wireViewToggle() {
  document.querySelectorAll('input[name="view_mode"]').forEach((r) => {
    if (r.dataset.wired === "1") return;
    r.dataset.wired = "1";
    r.addEventListener("change", (e) => {
      try {
        localStorage.setItem("lazyflat_view_mode", e.target.value);
      } catch (err) {}
      flushMapSize();
    });
  });
}

function restoreView() {
  let stored = null;
  try {
    stored = localStorage.getItem("lazyflat_view_mode");
  } catch (err) {}
  if (!stored) return;
  const el = document.querySelector(
    `input[name="view_mode"][value="${stored}"]`,
  );
  if (el && !el.checked) {
    el.checked = true;
    flushMapSize();
  }
}

function onReady() {
  initFlatsMap();
  wireViewToggle();
  restoreView();
}
document.addEventListener("DOMContentLoaded", onReady);
document.body && document.body.addEventListener("htmx:afterSwap", onReady);