Returning value from callback within Meteor.method

Question

I am running into something I don\'t understand with Meteor. I have this method, which takes a query, sends it to amazon, and then in the callback of that function I try to

Answer 1

You need to use Future to achieve your goal.

How to use future since Meteor 0.6?

Meteor.startup(function () {
 Future = Npm.require('fibers/future');

 // use Future here
}

Your method rewritten with Future:

Meteor.methods({
 'search': function(query) {

    var future = new Future();

    amazon.execute('ItemSearch', {
            'SearchIndex': 'Books',
            'Keywords': query,
            'ResponseGroup': 'ItemAttributes'
    }, function(results) {
       console.log(results);

       future["return"](results)

    });

    return future.wait();
 }
});

Now it should work.

Meteor.call('search', 'harry potter', function(error, response) {
   if(error){
    console.log('ERROR :', error);
   }else{
    console.log('response:', response);
   }

});

If you want to learn more about Future library I recommend watching screencast

---

Update on 26/12/2017

I just wanted to update this answer as you can achieve the same thing using promise and so, get rid of the "fibers" depedencies :)

An example is worth a thousand words

import scrap from 'scrap';

Meteor.methods({
    'hof.add'(el) {
        check(el, {
            _link: String
        });

        const promise = getHofInfo(el._link)
            .then((inserter) => {
                inserter.owner = Meteor.userId();
                Hof.insert(inserter);
                return true;
            })
            .catch((e) => {
                throw new Meteor.Error('500', e.message);
            });
        return promise.await();
    }
});


function getHofInfo(_link) {
    return new Promise((resolve, reject) => {
        scrap(_link, function (err, $) {
            if (err) {
                reject(err);
            } else {
                const attakers = $('#report-attackers').find('li').text();
                const defender = $('#report-defenders').find('li').text();
                const _name = attakers + ' vs ' + defender;
                const _date = new Date();
                resolve({ _name, _date, _link });
            }
        });
    });
}