How to fetch XML with fetch api

I'm trying to making a weather app that displays the weather and the temperature of many days of the week. I'm currently using openweathermap api for such task, the thing is that the information that I want (that is the date of the weather) only comes in xml format. Since I'm rebuilding it in ES6(ES2015) for academic reasons I wanted to also use the fetch api but since the fetch method parses it, it just delivers an error. so how can i fetch it or mby there is a better way to do it.

let apis = {
    currentWeather: { //get user selected recomendation weather
        api:"http://api.openweathermap.org/data/2.5/forecast/daily?lat=",
        parameters: "&mode=xml&units=metric&cnt=6&APPID=/*api key*/",
        url: (lat, lon) => {
            return apis.currentWeather.api + lat + "&lon=" + lon +
                   apis.currentWeather.parameters
        }
    }
};
function getCurrentLoc() { 
    return new Promise((resolve, reject) =>  navigator.geolocation
                                             .getCurrentPosition(resolve, reject))
}
function getCurrentCity(location) {
    const lat = location.coords.latitude;
    const lon = location.coords.longitude;
    return fetch(apis.currentWeather.url(lat, lon))
    .then(response => response.json())
    .then(data => console.log(data))
}
getCurrentLoc()
.then( coords => getCurrentCity(coords))

Solution 1:

Using native DOMParser getCurrentCity(location) can be written:

function getCurrentCity(location) {
    const lat = location.coords.latitude;
    const lon = location.coords.longitude;
    return fetch(apis.currentWeather.url(lat, lon))
        .then(response => response.text())
        .then(str => new window.DOMParser().parseFromString(str, "text/xml"))
        .then(data => console.log(data));
}

Solution 2:

I guess the error is coming from this function: response => response.json() since the response is not a valid JSON object (it's XML).

As far as I know, there is no native XML parser for fetch, but you can handle the response as text and use a third party tool to do the actual parsing, for example jQuery has a $.parseXML() function.

It will look something like:

function getCurrentCity(location) {
    const lat = location.coords.latitude;
    const lon = location.coords.longitude;
    return fetch(apis.currentWeather.url(lat, lon))
        .then(response => response.text())
        .then(xmlString => $.parseXML(xmlString))
        .then(data => console.log(data))
}