Add chart loading management

static/chartManager.js

@@ -0,0 +1,49 @@
+export let currentLoad = null;
+const loadInfo = new Map();
+
+export function newLoad(container) {
+  if (currentLoad) {
+    abortLoad(currentLoad);
+  }
+  reset(container);
+  const controller = new AbortController();
+  const token = { controller, charts: new Map() };
+  loadInfo.set(token, token);
+  currentLoad = token;
+  return token;
+}
+
+export function abortLoad(token) {
+  const info = loadInfo.get(token);
+  if (!info) return;
+  info.controller.abort();
+  info.charts.forEach(chart => {
+    try {
+      chart.destroy();
+    } catch (e) {}
+  });
+  loadInfo.delete(token);
+  if (currentLoad === token) {
+    currentLoad = null;
+  }
+}
+
+export function registerChart(token, id, chart) {
+  const info = loadInfo.get(token);
+  if (info) {
+    info.charts.set(id, chart);
+  } else {
+    chart.destroy();
+  }
+}
+
+export function reset(container) {
+  if (!container) return;
+  container.querySelectorAll('canvas').forEach(c => {
+    const chart = Chart.getChart(c);
+    if (chart) {
+      chart.destroy();
+    }
+  });
+  container.innerHTML = '';
+}