Alternative for .then() after request()

Question

I'm new to NodeJS. I have an asynchronous function

request({url: 'url',json: true}, function (error, response, body) {});

I want to call a function only after this function is invoked. I can't call a .then() here. What are the other alternatives for this situation?

Answer 1

You could try something like this

return new Promise(resolve => {
    request({
        url: "",
        method: "",
        headers: {},
        json: true
    }, function (error, response, body) {
        if(!error)
            resolve(body);
    })
}).then(value => {
    // process value here
})

Answer 2

Just pass it as your callback function:

function callback (err, res, body) {
   // Do what needs to be done here. 
}    
request({ url: 'url', json: true, someParam: true }, callback);

At the beginning of your callback function, check if err exists and if so, handle the error.

This article might help you.

You can only call then if your asynchronous function returns a Promise. But before you get into Promises, you should know the basics about Node.js.