Why I cannot using cookies variable value outside the cookie.get function? - electron

Question

I just began to learning using electron.
I have set a cookie and I want using it value.
function getCookie(cname) {
var value = {
name: cname
};
session.defaultSession.cookies.get(value, function (error, cookies) {
let cookieStr = ''
for (var i = 0; i < cookies.length; i++) {
let info = cookies[i];
cookieStr += `${info.name}=${info.value};`;
console.log(info.value, info.name);
let somevalue = info.value;
}
console.log(cookieStr);
alert(somevalue); //alert 1
});
alert(somevalue); //alert 2
}
</script>
I got the cookieStr value in console.log.
Then in somewhere place, I want to use cookieStr value by calling getcookie(cname) but it keep undefined. How to use the cookie value outside the function?
I have tried display the value with 'alert 1' inside the cookie.get function and it is work. But, the 'alert 2' which outside cookie.get function keep displaying undefined.
Thank you

Answer 1

Reading cookies in electron is an asynchronous function. So its better to call the the function with a callback to return value. or else promisify the function.
function getCookie(cname,callback) {
var value = {
name: cname
};
session.defaultSession.cookies.get(value, function (error, cookies) {
let cookieStr = ''
for (var i = 0; i < cookies.length; i++) {
let info = cookies[i];
cookieStr += `${info.name}=${info.value};`;
console.log(info.value, info.name);
let somevalue = info.value;
}
callback(cookieStr);
});
//alert(somevalue); //alert 2
}
getCookie('test',function(returnValue){
//use the return value here
})