AQI Widget Code

aqi.js

// Displays Air Quality Index based on station data from
// aqicn.org
//
// Requires an API token: https://aqicn.org/data-platform/token/#/
//
// Configuration: configure the widget "Parameter" with a query string
// containing the station name and API token, e.g:
// station=Burnaby North Eton, British Comlumbia, Canada&token=12345
//
// based on widget code by Jason Snell <[email protected]>
// https://gist.github.com/jasonsnell/4b458e2775e11ff7dd8b21dd26aa504e
// based on code by Matt Silverlock
// gradient routine contributed by Rob Silverii

const API_URL = "https://api.waqi.info/feed";
const qs = (s) =>
  JSON.parse(
    '{"' +
      decodeURI(s)
        .replace(/"/g, '\\"')
        .replace(/&/g, '","')
        .replace(/=/g, '":"') +
      '"}'
  );

async function getSensorData() {
  const params =
    (args && args.widgetParameter) || "station=shanghai&token=demo";
  const { token, station } = qs(params);
  console.log({ token, station });
  const url = `${API_URL}/${escape(station)}/?token=${token}`;
  let req = new Request(url);
  let json = await req.loadJSON();
  return json.data;
}

// Widget attributes: AQI level threshold, text label, gradient start and end colors, text color
const levelAttributes = [
  {
    threshold: 300,
    label: "Hazardous",
    startColor: "9e2043",
    endColor: "7e0023",
    textColor: "ffffff",
  },
  {
    threshold: 200,
    label: "Very Unhealthy",
    startColor: "8f3f97",
    endColor: "6f1f77",
    textColor: "ffffff",
  },
  {
    threshold: 150,
    label: "Unhealthy",
    startColor: "FF3D3D",
    endColor: "D60000",
    textColor: "ffffff",
  },
  {
    threshold: 100,
    label: "Unhealthy (S.G.)",
    startColor: "FFA63D",
    endColor: "D67200",
    textColor: "000000",
  },
  {
    threshold: 50,
    label: "Moderate",
    startColor: "ffff00",
    endColor: "cccc00",
    textColor: "000000",
  },
  {
    threshold: 0,
    label: "Good",
    startColor: "00e400",
    endColor: "00bb00",
    textColor: "000000",
  },
];

// Get level attributes for AQI
const getLevelAttributes = (level, attributes) =>
  attributes
    .filter((c) => level > c.threshold)
    .sort((a, b) => b.threshold - a.threshold)[0];

function calculateLevel(aqi) {
  let res = {
    level: "OK",
    label: "fine",
    startColor: "white",
    endColor: "white",
  };

  let level = parseInt(aqi, 10) || 0;

  // Set attributes
  res = getLevelAttributes(level, levelAttributes);
  // Set level
  res.level = level;
  return res;
}

async function run() {
  let wg = new ListWidget();
  wg.setPadding(20, 15, 10, 10);
  try {
    let data = await getSensorData();
    const { aqi } = data;
    let level = calculateLevel(aqi);
    let aqitext = aqi.toString();

    let startColor = new Color(level.startColor);
    let endColor = new Color(level.endColor);
    let gradient = new LinearGradient();
    gradient.colors = [startColor, endColor];
    gradient.locations = [0.0, 1];

    wg.backgroundGradient = gradient;

    let header = wg.addText("Air Quality");
    header.textColor = new Color(level.textColor);
    header.font = Font.regularSystemFont(15);

    let content = wg.addText(aqitext);
    content.textSize = 45;
    content.textColor = new Color(level.textColor);
    content.font = Font.semiboldRoundedSystemFont(45);

    let wordLevel = wg.addText(level.label);
    wordLevel.textColor = new Color(level.textColor);
    wordLevel.font = Font.boldSystemFont(15);

    let spacerOne = wg.addSpacer(10);

    let id = wg.addText(data.city.name);
    id.textColor = new Color(level.textColor);
    id.font = Font.mediumSystemFont(12);

    let updatedAt = data.time.s;
    let ts = wg.addText(`Updated ${updatedAt}`);
    ts.textColor = new Color(level.textColor);
    ts.font = Font.lightSystemFont(10);

    let spacerTop = wg.addSpacer();

    wg.url = data.city.url;
  } catch (e) {
    console.log(e);
    let err = wg.addText(`error: ${e}`);
    err.textSize = 10;
    err.textColor = Color.red();
    err.textOpacity = 30;
  }

  wg.presentSmall();
  Script.setWidget(wg);
  Script.complete();
}

await run();