Scriptable widget for Luftdaten.info

Luftdaten.js

// Variables used by Scriptable.
// These must be at the very top of the file. Do not edit.
// icon-color: cyan; icon-glyph: database;

const warningColor = new Color("#E50000")
const legendFont = 12
const valueFont = 24
const timeFont = 8

let sensor = 1721
let param = args.widgetParameter
if (param != null && param.length > 0) {
    sensor = param
}

const widget = new ListWidget()
const sensorValues = await fetchsensorValues()
await createWidget()

// used for debugging if script runs inside the app
if (!config.runsInWidget) {
    await widget.presentSmall()
}
Script.setWidget(widget)
Script.complete()

// build the content of the widget
async function createWidget() {

    widget.backgroundColor = new Color("#38b5ad", 1.0)

    const logoImg = await getImage('luftdaten-logo.png')

    widget.setPadding(16,6,6,6)

    // logo
    const logoImageStack = widget.addStack()
    logoImageStack.addSpacer()
    const wimg = logoImageStack.addImage(logoImg)
    wimg.imageSize = new Size(50,50)
    logoImageStack.addSpacer()

    // p1 value
    let row = widget.addStack()
    row.addSpacer()

    let column = row.addStack()
    column.layoutVertically()

    const p1Text = column.addText("PM10")
    p1Text.font = Font.mediumRoundedSystemFont(legendFont)
    p1Text.textColor = Color.white()

    const p1Value = column.addText(sensorValues[0].toString())
    p1Value.font = Font.mediumRoundedSystemFont(valueFont)
    if (sensorValues[0] > 30) {
        p1Value.textColor = warningColor
    } else {
        p1Value.textColor = Color.black()
    }
    row.addSpacer()

    // p2 value
    let row2 = widget.addStack()
    row2.addSpacer()

    let column2 = row2.addStack()
    column2.layoutVertically()

    const p2Text = column2.addText("PM2.5")
    p2Text.font = Font.mediumRoundedSystemFont(legendFont)
    p2Text.textColor = Color.white()

    const p2Value = column2.addText(sensorValues[1].toString())
    p2Value.font = Font.mediumRoundedSystemFont(valueFont)
    if (sensorValues[1] > 30) {
     p2Value.textColor = warningColor
    } else {
     p2Value.textColor = Color.black()
    }
    row2.addSpacer()

    // timestamp
    const timestampStack = widget.addStack()
    timestampStack.addSpacer()
    const timestr = sensorValues[2].replace(' ', 'T')
    const date = new Date(timestr + '+00')
    let timestampText = timestampStack.addText(date.toLocaleString())
    timestampText.font = Font.mediumRoundedSystemFont(timeFont)
    timestampText.textColor = Color.white()
    timestampStack.addSpacer()
}

async function fetchsensorValues() {
    let url
    let counter = 0
    url = 'https://data.sensor.community/airrohr/v1/sensor/' + sensor + '/'
    const req = new Request(url)
    const apiResult = await req.loadJSON()
    let p1
    let p2
    for (var i in apiResult[0].sensordatavalues) {
        if (apiResult[0].sensordatavalues[i].value_type == 'P1')
            p1 = apiResult[0].sensordatavalues[i].value
        else if (apiResult[0].sensordatavalues[i].value_type == 'P2')
            p2 = apiResult[0].sensordatavalues[i].value
    }
    return [p1, p2, apiResult[0].timestamp]
}

// get images from local filestore or download them once
async function getImage(image) {
    let fm = FileManager.local()
    let dir = fm.documentsDirectory()
    let path = fm.joinPath(dir, image)
    if (fm.fileExists(path)) {
        return fm.readImage(path)
    } else {
        // download once
        let imageUrl
        switch (image) {
            case 'luftdaten-logo.png':
                imageUrl = "https://luftdaten.info/wp-content/uploads/2018/01/luftdaten_logo_partner.png"
                break
            default:
                console.log(`Sorry, couldn't find ${image}.`);
        }
        let iconImage = await loadImage(imageUrl)
        fm.writeImage(path, iconImage)
        return iconImage
    }
}

// helper function to download an image from a given url
async function loadImage(imgUrl) {
    const req = new Request(imgUrl)
    return await req.loadImage()
}