Node.JS https request return JSON

Question

I have a question about the Node.js HTTPS request. The request goes to a server,which will return a JSON response. Then I want to parse the response and store it in a variable and use it with other functions.

let obj=JSON.parse(response);
return obj;

The functions I have written:

let protocol="https";
let hostStr="www.example.com";
let pathStr="***";

let students=makeRequest("ABCDEFG","getStudents"));
console.log(students);

function makeRequest(token,method){    
       let obj='';
        let options={
            host:hostStr,
            path:pathStr,
            method:"POST",
            headers:{"Cookie":"JSESSIONID="+token}
        };
        let https=require(protocol);
        callback = function(response){
            var str='';

            response.on('data',function(chunk){
                str+=chunk;
            });

            response.on('end',function(){
                obj=JSON.parse(str);
            });
        }
        let request=https.request(options,callback);
        request.write('{"id":"ID","method":"'+method+'","params":{},"jsonrpc":"2.0"}');
        request.end();
        return obj;
    }

I hope you can help me

Answer 1

To do what you want you need to understand the asynchrone side of Javascript. What you do can't work because the string is updated in an asynchronous callback. I have fix the part that didn't work.

 let protocol="https"; let hostStr="www.example.com"; let pathStr="***"; makeRequest("ABCDEFG","getStudents")) .then(students => { // here is what you want console.log(students); }); function makeRequest(token,method){ return new Promise(resolve => { let obj=''; let options={ host:hostStr, path:pathStr, method:"POST", headers:{"Cookie":"JSESSIONID="+token} }; let https=require(protocol); callback = function(response){ var str=''; response.on('data',function(chunk){ str+=chunk; }); response.on('end',function(){ obj=JSON.parse(str); resolve(obj); }); } let request = https.request(options,callback); request.write('{"id":"ID","method":"'+ method +'","params":{},"jsonrpc":"2.0"}'); request.end(); }); } 

Here you can read more about asynchonous in javascript