weather-board/src/data.js

var d3 = require('d3')

export function readxml(xmldoc) {
    const forcast = xmldoc.childNodes[0]
    const data = forcast.children[1]

    // Time
    const times = data.getElementsByTagName('time-layout')[0]
    let startTimes = []
    for (let time of times.getElementsByTagName('start-valid-time')) {
        const date = new Date(time.textContent)
        startTimes.push(date)
    }
    let endTimes = []
    for (let time of times.getElementsByTagName('end-valid-time')) {
        const date = new Date(time.textContent)
        endTimes.push(date)
    }

    // Temperature
    let temperatures = []
    for (let temp_type of data.getElementsByTagName('temperature')) {
        if (temp_type.attributes.type.nodeValue === 'hourly') {
            for (let temp of temp_type.getElementsByTagName('value')) {
                const degC = (parseFloat(temp.textContent) - 32) * (5.0/9.0)
                temperatures.push(degC)
            }
        }
    }

    // Cloud Cover
    let cloudCover = []
    const clouds = data.getElementsByTagName('cloud-amount')[0]
    for (let cloud of clouds.getElementsByTagName('value')) {
        cloudCover.push(parseFloat(cloud.textContent))
    }

    // Precipitation
    let precip = []
    const probabilityOfPrecipitation = data.getElementsByTagName('probability-of-precipitation')[0]
    for (let prop of probabilityOfPrecipitation.getElementsByTagName('value')) {
        precip.push(parseFloat(prop.textContent))
    }
    let precipQPF = []
    const hourlyQPF = data.getElementsByTagName('hourly-qpf')[0]
    for (let qpf of hourlyQPF.getElementsByTagName('value')) {
        if (qpf.getAttribute('xsi:nil') === "true") {
            precipQPF.push(0)
        } else {
            precipQPF.push(parseFloat(qpf.textContent))
        }
    }

    // Map
    const nElements = startTimes.length

    let forcastData = []
    let cloudData = []
    let precipData = []
    let precipQPFData = []
    cloudData.push({
        date: startTimes[0],
        coverage: 0
    })
    precipData.push({
        date: startTimes[0],
        probability: 0
    })
    precipQPFData.push({
        date: startTimes[0],
        qpf: 0
    })
    for (var i = 0; i < nElements; i++) {
        const midtimeScale = d3.scaleTime()
            .domain([0, 1])
            .range([startTimes[i], endTimes[i]])
        const midpointTime = midtimeScale(0.5)
        forcastData.push({
            date: midpointTime,
            temp: temperatures[i]
        })
        cloudData.push({
            date: midpointTime,
            coverage: cloudCover[i]
        })
        precipData.push({
            date: startTimes[i],
            probability: precip[i]
        })
        precipData.push({
            date: endTimes[i],
            probability: precip[i]
        })
        precipQPFData.push({
            date: startTimes[i],
            qpf: precipQPF[i]
        })
        precipQPFData.push({
            date: endTimes[i],
            qpf: precipQPF[i]
        })
    }
    cloudData.push({
        date: endTimes[endTimes.length - 1],
        coverage: 0
    })
    precipData.push({
        date: endTimes[endTimes.length - 1],
        probability: 0
    })
    precipQPFData.push({
        date: endTimes[endTimes.length - 1],
        qpf: 0
    })

    return {
        startTimes: startTimes,
        endTimes: endTimes,
        temperature: forcastData,
        clouds: cloudData,
        precip: precipData,
        precipQPF: precipQPFData,
    }
}