I have an issue generating a chart with CanvasJS .
Basically I get the data from the API, I can see and check the JSON array but when I'm going to generate the dataPoint for the graph I get 2 errors: data invalid on the data field and NaN on the value field.
Can someone give me a hint?
// Fetching the data
fetch('https://example.com/my/endpoint').then(response => {
return response.json();
}).then(data => {
// Work with JSON data here
var jsonData = data;
// Generating Data Points
var dataPoints = [];
for (var i = 0; i <= jsonData.length - 1; i++) {
dataPoints.push({ y: new Date(jsonData[i].source_ts), x: Number(jsonData[i].xyzw) });
console.log(dataPoints);
}
var chart = new CanvasJS.Chart("chartContainer", {
data: [
{
dataPoints: dataPoints,
type: "line",
}
]
});
chart.render();
}).catch(err => {
throw new Error( 'Impossible to get data' );
});
Cheers
You were not intreating correctly over data
due to which you were getting y:null
and x:NaN
.
Content inside data
is array of objects inside an array ie [[{}, {}, {}...]]
so you need to iterate accordingly.
Use this code:
data.forEach(function(array) {
array.forEach(function(arrayItem) {
dataPoints.push({
y: new Date(arrayItem.source_ts),
x: Number(arrayItem.renewablesobligationconsumption)
});
});
});
Below is complete working example. Now your dataPoints
is ready, you can use it anywhere you want:
// Fetching the data fetch('https://example.com/my/endpoint').then(response => { return response.json(); }).then(data => { // Generating Data Points var dataPoints = []; data.forEach(function(array) { array.forEach(function(arrayItem) { dataPoints.push({ y: new Date(arrayItem.source_ts), x: Number(arrayItem.xyzw) }); }); }); console.log(dataPoints); var chart = new CanvasJS.Chart("chartContainer", { data: [{ dataPoints: dataPoints, type: "line", }] }); chart.render(); }).catch(err => { throw new Error('Impossible to get data'); });
<br/> <:-- Just so that JSFiddle's Result label doesn't overlap the Chart --> <div id="chartContainer" style="height; 300px: width; 100%;"></div>
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