I'm newbie in javascript and I have a problem to parse Json
I read the similar question but none of them give me a correct answers.
in my code there are below functions that should parse a json file called wifi.txt when page loading.
function responsewifi(){
if(this.readyState==4 && this.status ==200){
myobj = JSON.parse(this.responseText);
document.getElementById("SSID").value = myobj.SSID;
document.getElementById("APKEY").value = myobj.APKEY;
document.getElementById("ESPAPNAME").value = myobj.ESPAPNAME;
document.getElementById("ESPAPKEY").value = myobj.ESPAPKEY;
var wifimodes = myobj.wifimode;
if(wifimodes=="STAmode"){document.getElementById("STAmode").checked = true;}
if(wifimodes=="APmode"){document.getElementById("APmode").checked = true;}
if(wifimodes=="MULTImode"){document.getElementById("MULTImode").checked = true;}
}
}
function processwificonfig()
{
regwifi.open("get","wifi.txt",true);
regwifi.onreadystatechange = responsewifi;
regwifi.send();
}
processwificonfig();
the problem is that when page load the code myobj = JSON.parse(this.responseText); doesn't work and its below code doesn't work too.
I try consol.log and alert("test") in every line of top code but just code before myobj = JSON.parse(this.responseText); work correctly
I get the following error
Uncaught SyntaxError: Unexpected end of JSON input
at JSON.parse (<anonymous>)
at XMLHttpRequest.responsewifi
myobj is a var
I code this for a NODEMCU ESP8266 project.
thanks you F. Müller
I write this answer for who has this problem as me
I tried for about 2 days to solve this problem
as F. Müller said problem was finding a correct json file
I realized that in spiffs memory of esp8266 there is a slash/ before files name
here I have to write
regwifi.open("get","/wifi.txt",true);
instead of
regwifi.open("get","wifi.txt",true);
in processwificonfig() function
and thats it
Try working with this... use as starting point:
<!DOCTYPE html>
<html lang="en">
<head>
<title>test</title>
</head>
<body>
<p id="SSID"></p>
<p id="APKEY"></p>
<p id="ESPAPNAME"></p>
<p id="ESPAPKEY"></p>
<script>
const xhr = new XMLHttpRequest(),
method = "GET",
url = "wifi.txt";
xhr.open(method, url, true);
xhr.onreadystatechange = function () {
if(xhr.readyState === XMLHttpRequest.DONE) {
var status = xhr.status;
if (status === 0 || (status >= 200 && status < 400)) {
// The request has been completed successfully
// console.log(xhr.responseText);
myobj = JSON.parse(xhr.responseText);
document.getElementById("SSID").innerText = myobj.SSID;
document.getElementById("APKEY").innerText = myobj.APKEY;
document.getElementById("ESPAPNAME").innerText = myobj.ESPAPNAME;
document.getElementById("ESPAPKEY").innerText = myobj.ESPAPKEY;
// wifimodes next...
} else {
console.log('Oh no! There has been an error with the request!');
}
}
};
xhr.send();
</script>
<!-- wifi.txt file content:
{
"SSID": "777",
"APKEY": "333",
"ESPAPNAME": "neo",
"ESPAPKEY": "222"
}
-->
</body>
</html>