Cesiumjs Core Utilities

// WRONG (removed in v1.134)
const name = defaultValue(options.name, "default");
const opts = defaultValue(options, defaultValue.EMPTY_OBJECT);

// CORRECT (v1.134+)
import { Frozen } from "cesium";
const name = options.name ?? "default";
const opts = options ?? Frozen.EMPTY_OBJECT;

import { Resource } from "cesium";

// Static shorthand: accepts a URL string or options object
const jsonData = await Resource.fetchJson({ url: "https://api.example.com/data.json" });

// data: URIs work with Resource.fetchJson -- useful for inline GeoJSON or test fixtures
const dataUrl = "data:application/json," + encodeURIComponent(JSON.stringify(geojson));
const parsed = await Resource.fetchJson({ url: dataUrl });

// Instance-based: construct once, reuse for multiple fetches
const resource = new Resource({
  url: "https://api.example.com/features",
  queryParameters: { format: "json", limit: "100" },
  headers: { "Authorization": "Bearer my-token" },
});
const features = await resource.fetchJson();
const text = await resource.fetchText();           // string
const buffer = await resource.fetchArrayBuffer();  // ArrayBuffer
const blob = await resource.fetchBlob();           // Blob
const image = await resource.fetchImage();         // HTMLImageElement or ImageBitmap

import { Resource } from "cesium";

const api = new Resource({
  url: "https://tiles.example.com/{version}/tiles/{z}/{x}/{y}.png",
  templateValues: { version: "v2" },
  headers: { "X-Api-Key": "abc123" },
});

// getDerivedResource inherits headers, proxy, and retry settings
const tile = api.getDerivedResource({
  templateValues: { z: "10", x: "512", y: "384" },
});
const tileImage = await tile.fetchImage();

// Modify query parameters on an existing resource
resource.setQueryParameters({ access_token: "<access-token>" });
resource.appendQueryParameters({ extra: "param" });

import { Resource, DefaultProxy } from "cesium";

// Retry on specific HTTP status codes
const resource = new Resource({
  url: "https://api.example.com/unstable",
  retryAttempts: 3,
  retryCallback: (resource, error) => {
    if (error.statusCode === 429) {
      return new Promise((resolve) => setTimeout(() => resolve(true), 2000));
    }
    return false;
  },
});

// DefaultProxy appends the target URL as a query parameter
const proxied = new Resource({
  url: "https://external-server.com/data.json",
  proxy: new DefaultProxy("/proxy/"),
});
// Request goes to: /proxy/?https%3A%2F%2Fexternal-server.com%2Fdata.json

import { Resource } from "cesium";

const resource = new Resource({ url: "https://api.example.com/upload" });
const result = await resource.post(JSON.stringify({ name: "test" }), {
  headers: { "Content-Type": "application/json" },
});
// resource.put() works the same way

import { Color } from "cesium";

const red = Color.RED;                                        // frozen constant
const orange = Color.ORANGE;                                  // frozen constant
const royalBlue = Color.ROYALBLUE;                           // frozen constant
const forestGreen = Color.FORESTGREEN;                       // frozen constant
const crimson = Color.CRIMSON;                               // frozen constant
const custom = new Color(0.2, 0.6, 0.8, 1.0);               // float constructor
const blue = Color.fromCssColorString("#3498db");             // hex string
const semiRed = Color.fromCssColorString("rgba(255,0,0,0.5)"); // CSS rgba()
const coral = Color.fromBytes(255, 127, 80, 255);            // 0-255 bytes
const hsl = Color.fromHsl(0.58, 0.8, 0.5, 1.0);             // hue/sat/light
const bright = Color.fromRandom({                             // constrained random
  minimumRed: 0.75, minimumGreen: 0.75, minimumBlue: 0.75, alpha: 1.0,
});

import { Color } from "cesium";

const base = Color.fromCssColorString("#3498db");
const translucent = base.withAlpha(0.5);                // new Color with alpha
const lighter = base.brighten(0.3, new Color());        // requires result param
const darker = base.darken(0.3, new Color());
const css = base.toCssColorString();                    // "rgb(52,152,219)"
const hex = base.toCssHexString();                      // "#3498db"
const bytes = base.toBytes();                           // [52, 152, 219, 255]
const equal = Color.RED.equals(new Color(1.0, 0.0, 0.0, 1.0)); // true

import { Event } from "cesium";

const onDataReceived = new Event();

// addEventListener returns a removal function
const removeListener = onDataReceived.addEventListener((data) => {
  console.log("Received:", data);
});

onDataReceived.raiseEvent({ id: 1, value: "test" }); // invoke all listeners
removeListener(); // unsubscribe

import { EventHelper } from "cesium";

const helper = new EventHelper();
helper.add(viewer.selectedEntityChanged, (entity) => {
  console.log("Selected:", entity?.name);
});

// clock.onTick fires every animation frame; enable the clock with shouldAnimate
viewer.clock.shouldAnimate = true;
helper.add(viewer.clock.onTick, (clock) => { /* per-frame logic */ });

helper.add(viewer.scene.globe.tileLoadProgressEvent, (queueLength) => {
  console.log("Tiles loading:", queueLength);
});

// Remove all listeners at once (e.g., in a destroy method)
helper.removeAll();

import { EventHelper, Color, Cartesian3 } from "cesium";

let tickCount = 0;
const label = viewer.entities.add({
  position: Cartesian3.fromDegrees(-30.0, 30.0),
  label: {
    text: "Ticks: 0",
    showBackground: true,
    backgroundColor: Color.BLACK.withAlpha(0.7),
    fillColor: Color.WHITE,
    font: "24px monospace",
  },
});

const helper = new EventHelper();
viewer.clock.shouldAnimate = true;
helper.add(viewer.clock.onTick, () => {
  tickCount++;
  label.label.text = "Ticks: " + tickCount;
});

import { RequestScheduler } from "cesium";

RequestScheduler.maximumRequests = 64;            // global max (default: 50)
RequestScheduler.maximumRequestsPerServer = 12;   // per-server max (default: 18)

// Override for known HTTP/2 servers
RequestScheduler.requestsByServer = {
  "api.cesium.com:443": 32,
  "assets.cesium.com:443": 32,
};

import { RuntimeError, formatError, Cesium3DTileset } from "cesium";

try {
  const tileset = await Cesium3DTileset.fromUrl("https://example.com/tileset.json");
  viewer.scene.primitives.add(tileset);
} catch (error) {
  if (error instanceof RuntimeError) {
    console.error("Failed to load tileset:", error.message);
  } else {
    console.error(formatError(error)); // extracts name, message, stack
  }
}

import { defined, clone, combine } from "cesium";

// defined: returns true if value is neither null nor undefined
if (defined(entity.billboard)) {
  entity.billboard.scale = 2.0;
}

// clone: shallow by default, pass true for deep
const obj = clone({ a: 1, nested: { b: 2 } }, true);

// combine: merge objects, first arg's keys take precedence
const merged = combine({ size: 20 }, { size: 10, color: "red" });
// { size: 20, color: "red" }

import { createGuid, buildModuleUrl } from "cesium";

const id = createGuid(); // "xxxxxxxx-xxxx-4xxx-yxxx-xxxxxxxxxxxx"

// Resolve paths relative to Cesium installation
const iconUrl = buildModuleUrl("Assets/Textures/maki/marker.png");

import { objectToQuery, queryToObject, getExtensionFromUri, getBaseUri } from "cesium";

const qs = objectToQuery({ key1: "value 1", key2: ["x", "y"] });
// "key1=value%201&key2=x&key2=y"

const parsed = queryToObject("key1=value%201&key2=x&key2=y");
// { key1: "value 1", key2: ["x", "y"] }

getExtensionFromUri("https://example.com/model.glb?v=2"); // "glb"
getBaseUri("https://example.com/data/model.glb");          // "https://example.com/data/"

import { destroyObject } from "cesium";

class MyWidget {
  constructor(viewer) {
    this._handler = new Cesium.ScreenSpaceEventHandler(viewer.canvas);
  }
  isDestroyed() { return false; }
  destroy() {
    this._handler.destroy();
    return destroyObject(this);
  }
}

import { AssociativeArray } from "cesium";

const items = new AssociativeArray();
items.set("building-1", { height: 50 });
items.set("building-2", { height: 80 });

items.get("building-1");       // { height: 50 }
items.contains("building-1");  // true

// Iterate without per-frame allocations
const values = items.values;
for (let i = 0; i < values.length; i++) { /* process values[i] */ }

items.remove("building-1");
items.removeAll();