I try to get data from the API and refresh the Pie chart on an Electron application page, but I can't refresh the value of the chart. The values on the chart never change. I tried this method with RGraph Gauge before and it worked, but with Electron doesn't refresh the value. What am I doing wrong? Thank you for your help. Screenshot of my electron application
<script>
const ipcRenderer = require("electron").ipcRenderer;
const {session} = require('electron').remote;
document.getElementById("backBtn").addEventListener("click",()=>{
ipcRenderer.send("btnBack","101");
});
temp = new RGraph.HorseshoeMeter({
id: 'temp',
min: 0,
max: 50,
value: 15,
options: {
colors: ["#3678c1", '#BED1E3'],
textColor: "#3678c1",
animationOptions: {frames: 60} // Doesn't need to be a string
}
}).draw();
hum = new RGraph.HorseshoeMeter({
id: 'hum',
min: 0,
max: 100,
value: 45,
options: {
colors: ["#3678c1", '#BED1E3'],
textColor: "#3678c1",
animationOptions: {frames: 60} // Doesn't need to be a string
}
}).draw();
iaq = new RGraph.HorseshoeMeter({
id: 'iaq',
min: 0,
max: 3000,
value: 1232,
options: {
colors: ["#3678c1", '#BED1E3'],
textColor: "#3678c1",
animationOptions: {frames: 60} // Doesn't need to be a string
}
}).draw();
async function getSessionInfo(){
let myPromise = new Promise(function(myResolve, myReject) {
session.defaultSession.cookies.get({name: "human_presence"}, (error,cookies)=>{
if(error){ myReject(error)}
if(cookies.length>0){
let arr = cookies[0];
if(arr.name === "human_presence" && ( (Date.now()-arr.expirationDate) < 600000)){
let obj = JSON.parse(arr.value);
myResolve(obj.accessToken);
}
else{ myResolve("Token bulunamadı")}
}
});
});
return await myPromise;
}
function httpCall(){
getSessionInfo().then(function (val){
let method = "GET";
let url = "http://localhost:4000/classroom/101";
let xmlHttpRequest = new XMLHttpRequest();
xmlHttpRequest.addEventListener("readystatechange", function() {
if(this.readyState === 4) {
console.log(this.responseText);
let obj = JSON.parse(this.responseText);
console.log(obj);
document.getElementById("dateTime-101").innerHTML = "Son Kayıt Zamanı : "+obj.created;
document.getElementById("NoS-101").innerHTML = "Öğrenci Sayısı : "+obj.NoS;
temp.value = parseInt(obj.Temp);
hum.value = parseInt(obj.Hum);
iaq.value = parseInt(obj.IAQ);
RGraph.redrawCanvas(temp.canvas);
RGraph.redrawCanvas(hum.canvas);
RGraph.redrawCanvas(iaq.canvas);
}
});
xmlHttpRequest.open(method, url);
xmlHttpRequest.setRequestHeader('Authorization', 'Bearer ' + val);
xmlHttpRequest.send();
})
}
window.onload = httpCall();
window.setInterval(function(){
httpCall();
}, 20000);
Here's my answer that was posted to the RGraph forum:
This is as a result of the HorseShoe meter not really being a 'real' RGraph chart object - but an adaptation of the Pie chart. As a result I think it's easier to just redraw the entire chart when you update it.
Here's some code:
<canvas id="cvs" width="400" height="400">[No canvas support]</canvas>
<script>
function draw (value)
{
RGraph.reset(document.getElementById('cvs'));
new RGraph.HorseshoeMeter({
id: 'cvs',
min: 0,
max: 10000,
value: value,
options: {
}
}).roundRobin();
}
delay = 2000;
function update ()
{
var value = Math.random(0, 1000);
draw(value * 10000);
// Call ourselves again
setTimeout(update, delay);
}
setTimeout(update, delay);
</script>
And here's a CodePen of the code: