Qml Weather▲
By default the application uses static test data to mimic a weather forecast. You can also obtain an application id from http://www.worldweatheronline.com/ to get access to weather API provided by World Weather Online. You can then give your application id as a parameter to the Qml Weather executable to make it use live data.
For example:
bin\qmlweather.exe 1234567890abcdef123456Running the Example▲
To run the example from Qt Creator, open the Welcome mode and select the example from Examples. For more information, visit Building and Running an Example.
Using Charts in Qt Quick Applications▲
The example application uses a ChartView and a some series to visualize weather data:
ChartView {
id: chartView
title: "Weather forecast"
BarCategoryAxis {
id: barCategoriesAxis
titleText: "Date"
}
ValueAxis{
id: valueAxisY2
min: 0
max: 10
titleText: "Rainfall [mm]"
}
ValueAxis {
id: valueAxisX
// Hide the value axis; it is only used to map the line series to bar categories axis
visible: false
min: 0
max: 5
}
ValueAxis{
id: valueAxisY
min: 0
max: 15
titleText: "Temperature [°C]"
}
LineSeries {
id: maxTempSeries
axisX: valueAxisX
axisY: valueAxisY
name: "Max. temperature"
}
LineSeries {
id: minTempSeries
axisX: valueAxisX
axisY: valueAxisY
name: "Min. temperature"
}
BarSeries {
id: myBarSeries
axisX: barCategoriesAxis
axisYRight: valueAxisY2
BarSet {
id: rainfallSet
label: "Rainfall"
}
}To get data with weather forecast data, we make an HTTP GET request to World Weather Online. We request the response in JSON data format.
// Make HTTP GET request and parse the result
var xhr = new XMLHttpRequest;
xhr.open("GET",
"http://free.worldweatheronline.com/feed/weather.ashx?q=Jyv%c3%a4skyl%c3%a4,Finland&format=json&num_of_days=5&key="
+ weatherAppKey);
xhr.onreadystatechange = function() {
if (xhr.readyState == XMLHttpRequest.DONE) {
var a = JSON.parse(xhr.responseText);
parseWeatherData(a);
}
}
xhr.send();The JSON response contains an array of forecast data:
// Loop through the parsed JSON
for (var i in weatherData.data.weather) {
var weatherObj = weatherData.data.weather[i];That is then used as input data for our series and a ListModel we use as a container for weather icon URLs:
// Store temperature values, rainfall and weather icon.
// The temperature values begin from 0.5 instead of 0.0 to make the start from the
// middle of the rainfall bars. This makes the temperature lines visually better
// synchronized with the rainfall bars.
maxTempSeries.append(Number(i) + 0.5, weatherObj.tempMaxC);
minTempSeries.append(Number(i) + 0.5, weatherObj.tempMinC);
rainfallSet.append(i, weatherObj.precipMM);
weatherImageModel.append({"imageSource":weatherObj.weatherIconUrl[0].value});